CROSSING BOUNDARIES 50th International Symposium on Novelties in Textiles 10th Conference on Information and Graphic Arts Technology PROCEEDINGS 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 50th International Symposium on Novelties in Textiles 10th Conference on Information and Graphic Arts Technology PUBLISHER University of Ljubljana, Faculty of Natural Sciences and Engineering Department of Textiles, Graphic Arts and Design Chair of Textile and Clothing Engineering Chair of Information and Graphic Arts Technology EDITORS Marija Gorjanc, Brigita Tomšič, Helena Gabrijelčič Tomc, Urška Vrabič Brodnjak EDITORIAL BOARD Marija Gorjanc, Brigita Tomšič, Helena Gabrijelčič Tomc, Urška Vrabič Brodnjak TECHNICAL EDITOR Tara Tkalec COVER DESIGN Tara Tkalec Authors take the sole responsibility for the content of their work. May 2025 Kataložni zapis o publikaciji (CIP) pripravili v Narodni in univerzitetni knjižnici v Ljubljani COBISS.SI-ID 236746243 ISBN 978-961-7189-20-9 (PDF) ORGANIZER University of Ljubljana, Faculty of Natural Sciences and Engineering Department of Textiles, Graphic Arts and Design Chair of Textile and Clothing Engineering Chair of Information and Graphic Arts Technology 50th International Symposium on Novelties in Textiles ORGANISING COMMITTEE Chair: • Marija Gorjanc University of Ljubljana, Slovenia Members: • Barbara Golja University of Ljubljana, Slovenia • Mateja Kert University of Ljubljana, Slovenia • Klara Kostajnšek University of Ljubljana, Slovenia • Nina Čuk University of Ljubljana, Slovenia • Barbara Luštek Preskar University of Ljubljana, Slovenia SCIENTIFIC COMMITTEE Chair: • Brigita Tomšič University of Ljubljana, Slovenia Members: • Matejka Bizjak University of Ljubljana, Slovenia • Andrej Demšar University of Ljubljana, Slovenia • Petra Eva Forte Tavčer University of Ljubljana, Slovenia • Almira Sadar University of Ljubljana, Slovenia • Barbara Simončič University of Ljubljana, Slovenia • Živa Zupin University of Ljubljana, Slovenia • Ahmet Cay Ege University, Izmir, Turkey • Özgür Ceylan Eskisehir Technical University, Eskişehir, Turkey • Ada Ferri Politecnico di Torino, Torino, Italy • Igor Jordanov Saints Cyril and Methodius University of Skopje, Skopje, Macedonia • Daiva Mikučionienė Kaunas University of Technology, Kaunas, Lithuania • Maja Radetić University of Belgrade, Belgrade, Serbia • Snežana Stanković University of Belgrade, Belgrade, Serbia • Torsten Textor Reutlingen University, Reutlingen, Germany • Antoneta Tomljenović University of Zagreb, Zagreb, Croatia 10th Conference on Information and Graphic Arts Technology ORGANISING COMMITTEE Chair: • Helena Gabrijelčič Tomc University of Ljubljana, Slovenia Members: • Jon Brce University of Ljubljana, Slovenia • Gregor Franken University of Ljubljana, Slovenia • Matevž Hribernik University of Ljubljana, Slovenia • Gašper Mesojedec University of Ljubljana, Slovenia • Marica Starešinič University of Ljubljana, Slovenia • Veronika Štampfl University of Ljubljana, Slovenia • Tara Tkalec University of Ljubljana, Slovenia • Primož Weingerl University of Ljubljana, Slovenia • Barbara Luštek Preskar University of Ljubljana, Slovenia PROGRAMME AND REVIEW COMMITTEE Chair: • Urška Vrabič Brodnjak University of Ljubljana, Slovenia Members: • Jure Ahtik University of Ljubljana, Slovenia • Primož Fijavž University of Ljubljana, Slovenia • Jože Guna University of Ljubljana, Slovenia • Klemen Možina University of Ljubljana, Slovenia • Tomislav Cigula University of Zagreb Croatia • Anne Blayo Grenoble INP – Pagora, France • Jesenka Pibernik University of Zagreb, Croatia • Sanja Mahović Poljaček University of Zagreb, Croatia • Magdolna Pal University of Novi Sad, Serbia • Iva Jestratijević University of North Texas, Texas, USA • Dimitrina Todorova University of Chemical Technology and Metallurgy – Sofia, Bulgaria • Suzana Parreira University of Lisbon, Portugal • Gerry Leonidas University of Reading, United Kingdom • Maja Brozović University of Zagreb, Croatia • Igor Majnarić University of Zagreb, Croatia • Iva Šarčević University of Zagreb, Croatia • Nemanja Kašiković University of Novi Sad, Serbia • Živko Pavlović University of Novi Sad, Serbia • Ivana Tomić University of Novi Sad, Serbia • Marketa Držkova University of Pardubice, Czech Republic • Ivana Tartaro Bujak Ruđer Bošković Institute, Croatia • Anna Witek- Krowiak Wroclaw University of Science and Technology, Poland • Smarak Bandyopadhyay Institute of Agrophysics (IA PAS), Poland • Irma Puškarević Wichita State University, Kansas, USA SPONSORS: CONTENTS KEYNOTE LECTURES Closing the loop: application of transformative sustainability pedagogy and action research to implement scalable zero textile waste model at a university campus Iva Jestraijević.......................................................................................................................................................15 Living in a container Dan Podjed............................................................................................................................................................16 Innovating the skies: Pipistrel’s composite revolution with textiles, advanced materials and 3D techniques in aviation Ingrid Heuffel Berginc............................................................................................................................................21 ISNT INVITED LECTURES BETI‘s transformation from a labour–intensive to a development–and innovation –oriented company Petra Kovačič...........................................................................................................................................25 Innovative material and ethics exploration in fashion: the work of Tina Gorjanc Tina Gorjanc Safhalter..............................................................................................................................26 TEXTILE FIBERS Analysis of silkworm bombyx mori l. cocoons made after flat spinning Tatjana Rijavec, Alenka Šalej Lah and Rebeka Lucijana Berčič..............................................................35 Degumming of silk produced in Slovenia Petra Forte Tavčer, Maša Šturm and Tatjana Rijavec..............................................................................42 Dimensional stability of silk blend knitted fabrics Sabina Gabrovšek and Živa Zupin...........................................................................................................47 SUSTAINABLE AND ECO-FRIENDLY TEXTILE MATERIALS Natural protection of bacterial cellulose during incubation Linda Ogrizek, Janja Lamovšek, Franci Čuš and Marija Gorjanc...........................................................55 Vegan leather wallet made with apple waste Ismet Ege Kalkan, Günseli Aksoy Oral, Ayşegül İlkentapar, Figen Temiz-Dişlioğlu, Nurcan Tiryaki, Sena Şahin and Umut Kivanc Sahin...............................................................................61 Characterization of melt-extruded PA 6 filaments modified with ZnO nanoparticles Anja Ludaš Dujmić, Sanja Ercegović Ražić, Andrea Jurov, Bernarda Marković, Nino Dimitrov and Ivona Vidić Štrac.........................................................................................................65 UV radiation protection of cotton and wool functionalised with hop leaves Sebastijan Šmid, Nika Pirš, Klara Močenik and Marija Gorjanc...............................................................71 Pigment printing with dye extracts from invasive alien plants Maja Klančnik and Katarina Lampič.........................................................................................................77 SMART AND FUNCTIONAL TEXTILES Polypropylene nonwoven material modified with (3-aminopropyl) trialkoxysyloxane and Ag-based nanoparticles Darka Marković, Brigita Tomšič, Vanja Tadić, Tatjana Ilic-Tomic, Barbara Simončič and Maja Radetić......................................................................................................................................87 Multifunctional TiO based coatings for advanced textile applications 2 Mohammad Mamunur Rashid, Barbara Simončič, Ivan Jerman and Brigita Tomšič...............................93 The research journey: investigating the role of textile properties in bacterial adhesion Nina Čuk, Barbara Simončič, Klara Kostajnšek, Matejka Bizjak, Rok Fink and Brigita Tomšič.............100 Environmentally friendly TiO2/graphitic carbon nitride nanocomposite for multifunctional cotton fabric Dominika Glažar, Brigita Tomšič, Danaja Štular, Ivan Jerman, Raghuraj S. Chouhan and Barbara Simončič............................................................................................................................105 Development of self-cleaning viscose fabric functionalized with a titanium dioxide-coupled reduced graphene oxide in combination with chitosan Klara Močenik, Barbara Simončič and Brigita Tomšič.............................................................................112 Fabrication of durable electroconductive fibrous composites for wearable electronics Alenka Ojstršek and Laura Jug...............................................................................................................117 Eco-friendly hydrophobic textiles: a shift from PFAS to sustainable bio-polymers Barbara Golja, Blaž Stres, Uroš Novak, Blaž Likozar and Anja Verbič...................................................123 Sustainable flame retardant solutions: tuning ammonium phytate concentration for silk coatings Maja Blagojevič, Barbara Simončič, Ivan Jerman, Ana Drinčić and Brigita Tomšič................................130 Kombucha-extract-mediated green synthesis of silver nanoparticles for antibacterial silk textiles Nika Pirš, Barbara Simončič, Rok Fink and Brigita Tomšič....................................................................137 Functionalization of silk with green chitosanꟷaloe veraꟷessential oil composite for medical application Laura Cimperman, Barbara Simončič, Rok Fink and Brigita Tomšič......................................................143 Application of inclusion complexes β-cyclodextrin-citrus essential oil in the printing procedure on cotton fabric Sandra Flinčec Grgac, Daria Katinić, Ana Sutlović and Ana Palčić........................................................149 Formation of halochromic polyamide/elastane knitted fabric by screen printing method Mateja Kert and Špela Jerebic...............................................................................................................155 Durability of thermochromic ink printed on textile Diana Gregor-Svetec and Tina Flerin.....................................................................................................162 The auxetic properties of woven fabric Klara Kostajnšek, Sebastijan Šmid, Nuša Klančar and Matejka Bizjak..................................................167 INNOVATIVE CHEMICAL TEXTILE PROCESSING Hydrophilicity and capilarity of cotton fabric cationized during mercerization process Anita Tarbuk, Ivona Nemčić and Tihana Dekanić...................................................................................173 The role of trisodium phosphate in enhancing acidic dyeing of nylon fabrics Gaye Duman, Özgür Baki̇, Mert Bakirli and Güngör Durur.....................................................................179 Comparison of inkjet printing with reactive dyes on cotton fabric impregnated with alginate or polyacrylate thickener Petra Forte Tavčer..................................................................................................................................185 Trials of dry-air fixation of digitally printed reactive dyes on cotton fabrics Petra Forte Tavčer..................................................................................................................................191 Colourfastness properties of digitally printed pigments on cotton/lycra knitted fabric Mateja Kert, Egzona Rukovci and Petra Eva Forte Tavčer.....................................................................199 Research of the amount of fibres fragments shedding in washing process of a standard 50/50% pes/cotton knitted fabric Agata Vinčić, Tanja Pušić, Ana Šaravanja and Lamia Farhat.................................................................206 INNOVATIVE TEXTILE PROCESSING, DIGITALISATION AND INDUSTRY 5.0 Computerized creation of novelty weaves Dušan Peterc.........................................................................................................................................213 Creating a database for operation list in garment production process Selma Imamagić, Anica Hursa Šajatović and Bosiljka Šaravanja..........................................................220 TEXTILE BASED COMPOSITES AND TECHNICAL TEXTILES The influence of the layer structure on the durability of textile laminates Dunja Šajn Gorjanc and Barbara Golja..................................................................................................227 Bibliometric analysis of textile waste research Danica Dolničar and Irena Sajovic.........................................................................................................232 COMFORT AND QUALITY CONTROL OF TEXTILES Influence of the woven fabrics surface hairiness on their electrical resistance under different atmospheric conditions Juro Živičnjak and Antoneta Tomljenović................................................................................................242 Comparison of absorbency propperties of disposable and reusable sanitary padstitle of the paper Blažka Kumer and Živa Zupin.................................................................................................................249 TEXTILE AND CLOTHING DESIGN Sustainable practices in Slovenian fashion landscape Tanja Devetak........................................................................................................................................256 From urban streets to sandy shores: exploring the “city to beach” trend in fashion Özgür Ceylan, Emel Aydin, Irmak Taş, Nesligül Kiliç, Neval Ergun, Aslihan Arpinar and Tuğçe Kaynak..................................................................................................................................262 Innovating together: digital fashion learning through collaboration Marjeta Čuk, Elena Fajt, Alenka More, Nastja Sagadin Grmek and Tanja Nuša Kočevar......................268 Sustainability at KOTO Nastja Sagadin Grmek............................................................................................................................274 Design of a maternity collection with multifunctional properties Öykü Elmas, Ekin Üstem and Ecem Alagöz...........................................................................................280 Design of a sleepwear collection with cooling effect Ecem Alagöz, İsmet Ege Kalkan and Umut Kivanç Şahin......................................................................285 Use of japanese knotweed in woven textiles Kristi Komel and Katja Burger Kovič.......................................................................................................289 Bauhus inspired home textiles and cardboard modular furniture for children Tasja Videmšek and Katja Burger Kovič.................................................................................................295 TEXTILE EDUCATION Service learning in textile, clothing and fashion education Alenka Pavko Čuden, Barbara Simončič, Brigita Tomšič, Klara Kostajnšek and Matejka Bizjak...........301 Texunite – Erasmus+ project on service learning in the field of sustainability in textile and fashion education Matejka Bizjak, Alenka Pavko Čuden, Barbara Simončič, Manuela Bräuning, Mirela Blaga, Zlatina Kazlacheva, Mustafa Ertekin, Dirk Höfer and Anne-Marie Grundmeier.....................................308 CIGT INVITED LECTURES Implementation of the EU packaging and packaging waste regulation (PPWR) for Slovenia and Europe: challenges and opportunities Gregor Lavrič.........................................................................................................................................315 Exploring sculptural realism through wax modeling and 3D printing: a personal artistic evolution Anna Sacher Santana............................................................................................................................319 USER INTERFACE AND USER EXPERIENCE Use of generative artificial intelligence tools in transforming design process Lovro Frece and Jure Ahtik.....................................................................................................................321 Engaging the senses: a study of synesthetic design in motion graphics Jesenka Pibernik, Jurica Dolić, Marta Jagačić and Filip Cvitić...............................................................327 Exploring AI-driven personalisation for emotional design: the impact of custom content on emotional connection Neda M. Keresteš, Tanja Radovanović, Ivana Tomić, Sandra Dedijer, Magdolna Pal, Jelena Kerac and Gala Golubović..........................................................................................................334 Analysis of the relevance and appeal of the visual presentation of meat products generated using artificial intelligence Lucija Brina Arvaj, Tatjana Šubic and Jure Ahtik.....................................................................................344 Inclusivity as a value in informal and formal primary school education - example of visualizing children’s user pathways Anja Sarjanović, Delfina Fileva, Melita Kožuh, Brita Mandelj, Alja Krklec and Helena Gabrijelčič Tomc..................................................................................................................351 DESIGN AND TYPOGRAPHY A bibliometric analysis of typography research Danica Dolničar, Klementina Možina and Irena Sajovic.........................................................................359 Typography study practices (letters and shapes: collection of typographic exercises) Domen Fras............................................................................................................................................368 Adapting book cover design based on its target group Nuša Gabrijel, Valentina Smej Novak and Klementina Možina..............................................................376 How comprehensibility of packaging symbols depends on the level of environmental awareness of consumers Anđela Brekalo, Ivana Čalić, Luka Ljuban, Marina Šuša, Antonela Zvonković, Dorotea Kovačević and Maja Brozović...................................................................................................382 Comparison of a self-created visual corporate identity with one generated by artificial intelligence Sara Mužar, Tanja Medved and Helena Gabrijelčič Tomc......................................................................390 PACKAGING Prospects for the future of printed packaging in the circular economy Csaba Horváth and László Koltai...........................................................................................................406 Paper bags made from annual plants Ana Štrucelj and Klemen Možina............................................................................................................415 Impacts of printed intelligent elements on cardboard packaging recyclability: method evaluation and findings Patricija Pevec, Tea Kapun and Diana Gregor Svetec...........................................................................423 Sustainable gift packaging: design guidelines based on eco-design principles Andreja Pogačar and Diana Gregor-Svetec...........................................................................................429 Designing cardboard packaging for ceramic product transportation and brand identity development Sandra Grlj and Urška Vrabič-Brodnjak..................................................................................................434 Sustainable production of bacterial nanocellulose from komagataeibacter xylinus using citrus peel and gamma irradiation Ivana Tartaro Bujak, Maro Bujak, Ivan Marić, Anđela Pustak, Mirjam Leskovšek and Urška Vrabič-Brodnjak.....................................................................................................................440 A global assessment of cosmetic packaging trends and consumer preferences Urška Vrabič-Brodnjak and Iva Jestratijević...........................................................................................446 Packaging papers’ antimicrobial properties through native chemical additives treatment or coating Urška Vrabič-Brodnjak, Dimitrina Todorova and Nikolay Yavorov..........................................................453 2D AND 3D PRINTING Enhancing printability and runnability related factors in various inkjet print heads while printed on various paper substrates Sandeep Boora and Anjan Kumar Baral................................................................................................460 Innovative approaches to color reproduction on 3D printed flat and low-relief surfaces Jon Brce, Matej Pivar and Deja Muck....................................................................................................467 Influence of low temperature on mechanical stability of inkjet prints Maša Šraj, Barbara Blaznik and Sabina Bračko....................................................................................475 Screen printing with dyes from invasive alien plants Maja Klančnik and Katarina Lampič.......................................................................................................480 Reproduction of colour patches on textile and paper materials Ana Mendizza and Raša Urbas..............................................................................................................489 PHOTOGRAPHY AND COLORIMETRY Comparative study of noise reduction techniques for photographic image enhancement Ivana Jurič, Ivana Tomić, Sandra Dedijer, Magdolna Pal, Nemanja Kašiković and Katarina Maričić.....498 Comparison of shadows created with geometric projection, 3D rendering and physical experiment for different photographic light sources Veronika Štampfl and Jure Ahtik.............................................................................................................504 Reflectance spectra reconstruction from flatbed scanner-based RGB values using artificial neural network Mihael Lazar and Aleš Hladnik................................................................................................................512 SUBSTRATES AND STANDARDIZATION Slovenian institute for standardization and work of technical committees graphic technology, packaging - sales and grouped and pulp, paper, board and products Mojca Lampič.........................................................................................................................................521 Starch-based films reinforced with bacterial nanocellulose as PH indicators in smart packaging Sanja Mahović Poljaček, Tamara Tomašegović, Igor Karlovits, Urška Kavčič and Gregor Lavrič..........527 Screen-printed irreversible thermochromic indicators utilising single and mixed leuco dye systems Eva Pogorelc, Marta Klanjšek Gunde, Ondrej Panák and Raša Urbas..................................................534 Environmentally friendly coatings and their effect on thermochromic printing ink functionality Teodora Lukavski, Rahela Kulčar, Marina Vukoje, Katarina Itrić Ivanda and Tomislav Cigula................540 The visual appearance of pearlescent pigments coated with cellulose nanocrystal (CNC) binder Mirica Karlovits, Urška Kavčič, Blaž Likozar and Uroš Novak................................................................547 Colour stability of reversible thermochromic composite Katarina Jenko, Marta Klanjšek Gunde, Ondrej Panák and Raša Urbas...............................................553 The influence of the metallic substrate‘s embossing process and the possibility of printing white electroink Igor Majnarić, Meri Huljev, Stanko Bauk and Filip Macan.......................................................................559 Influence of glycerol concentration on the wetting properties of the methylcellulose coating Tomislav Cigula, Teodora Lukavski, Marina Vukoje, Rahela Kulčar and Katarina Itrić Ivanda...............570 COMPUTER GENERATED GRAPHICS AND ANIMATION From video to character animation for 3D theater production: a pilot study Tamara Ilić, Bojan Banjanin and Jelena Kerac.......................................................................................575 Visualizations in computer graphic – a collaborative bridge between museum and higher education research institution Tanja Nuša Kočevar, Aleksandra Nestorović and Helena Gabrijelčič Tomc...........................................581 Interpretation of stop-motion animation in 3D computer technique Ivana Pika Schlegl, Andrej Iskra and Tanja Nuša Kočevar.....................................................................588 Widespread visualizations with 3D technologies Boris Beja, Lan Fabjan, Tis Loris Lavrič, Eva Lap and Žiga Ceglar........................................................594 KEYNOTE LECTURES ORAL PRESENTATION CLOSING THE LOOP: APPLICATION OF TRANSFORMATIVE SUSTAINABILITY PEDAGOGY AND ACTION RESEARCH TO IMPLEMENT SCALABLE ZERO TEXTILE WASTE MODEL AT A UNIVERSITY CAMPUS Iva Jestraijević1 1University of North Texas, Texas, United States To address the textile industry’s waste issues, textile waste (TW) prevention programs are crucial. The Transformative Sustainability Pedagogy (TSP) approach has been praised for using educational interventions to create transformational sustainability learning in higher education settings. From the TSP perspective, university campuses, as living labs, represent perfect conditions for conducting action research providing students opportunities to “get their hands dirty” while trying to find solutions for existing problems that go far beyond the classroom. This study contributes to the scholarship on sustainability education in the postsecondary textile and apparel field by providing practical guidance on embedding TSP and action research into the purposeful creation of a campus wide TW prevention project. In March 2024, action research was undertaken by a faculty member at a large Southwestern university to support transformative learning about TW prevention through a yearlong campus project geared towards the collection and redirection of TW from local communities and landfills through creative reuse, recycling, donation, and swap events. This project had four main objectives: 1.) to use campus as a living laboratory for testing and implementing solutions for circular, closed-loop TW systems; 2.) to engage students in action research in which students were taught how to collect, sort, manage, and divert TW during one school year; 3.) to collect data on TW diversion rates iteratively assessing social and environmental benefits of the project; 4.) to propose tested, scalable and replicable solutions to tackle TW on a university campus. The results demonstrated the high effectiveness of the zero TW project and TSP. Within a year, the achieved environmental impact included over 8,280 collected items which resulted in the diversion of 2.2 tons (4840 pounds) of textiles from local landfills. Social impact accounted for 67% of collected items that were given back to those in need. In financial terms, this would be equivalent to $13,558.21 of monetary savings that would be otherwise spent if all recipients of free garments purchased them in a thrift store. The project engaged 200 student volunteers, while close to 600 students attended thrifting and sorting events. Researchers collected 224 written reflections where students unanimously commented on how participation in this project transformed their awareness of TW issues, their attitudes, and behaviors. Students echoed numerous benefits that this project created. Specifically, 45% of comments praised the environmental impact of the project, 25% praised the accessibility to clothing the initiative offered, 57% valued the community-building, and 15% made note of financial relief. The identified advantages of living lab and TSP are many. First, this project offers practical and tangible benefits as items recovered are reused and they are prevented from entering a landfill. Second, project offers replicable models for other educational institutions. Third, TSP, in the context of live labs, presents a powerful tool that can transform a campus from a passive to an active environment for teaching and learning. Lastly, this project opened a door for community building, fostering a sense of belonging and shared purpose among individuals that otherwise would not be connected. Keywords: zero textile waste, Transformative Sustainability Pedagogy, university campus, textile waste sorting, community building 15 ORAL PRESENTATION LIVING IN A CONTAINER Dan Podjed1 1Research Center of the Slovenian Academy of Sciences and Arts, Institute of Slovenian Ethnology, Slovenia Abstract: This article examines the container as a metaphor for globalization, standardization and isolation in a time of unprecedented technological development. Through an ethnographic case study of the earthquake in Petrinja, Croatia, it shows how containers have become a central element in the organization of human life in times of crisis and beyond. Using examples ranging from post-earthquake settlements to shopping malls and stadiums, the article argues that containers symbolize a broader societal trend towards modular, interchangeable and increasingly alienated lives within predefined boundaries – both in physical and digital reality. The discussion establishes a link between this „container life“ and broader processes of globalization, late capitalism and digital isolation, suggesting that our existence is becoming increasingly compartmentalized – physically, digitally, social-ly, ideologically and spiritually. Keywords: container; globalization; standardization; isolation; post-disaster recovery 1. INTRODUCTION In an era defined by the movement of goods, ideas, and people, the container has become one of the central sym-bols of globalization. Emerging from the post-WWII drive for efficiency and compatibility, it embodies the pursuit of standardization and homogenization that characterizes global interconnectedness. However, the container is not just a technical and industrial innovation; instead, it can be understood as a “homogenizing machine,” shap-ing economies, societies, cities, settlements, and even individual ways of living. From the standardized ports of international trade to the ad hoc container settlements, the container has infiltrated daily existence far beyond its original logistical function. This paper, based on ethnographic field research, carried out in 2023, explores the metaphorical meaning of containers, drawing connections between their use in post-disaster locations and their broader significance in a world increasingly organized into modular, isolated, and interchangeable units. In doing so, it asks whether “con-tainerization” reflects deeper social transformations toward alienation, standardization, and life within ever more rigid boundaries and confined structures. 2. THEORETICAL BACKGROUND The image of universality, standardization, and homogenization, represented by a container, is important for un-derstanding the phenomenon associated with globalization. Creating comparability is a central feature of global-ization, explains Thomas Hylland Eriksen (2014) and points to shipping containers as a prerequisite for modern globalization that is just as important as the launch of the first communications satellites. Why did the container change the world so much? Before standardized containers were introduced in shipping, goods were loaded directly from trucks or trains onto ships. In the mid-1950s, Malcolm McLean, a truck driver, came up with an innovation: he designed a standard-sized container to make it easier to load and transport goods, thereby contributing to the standardization of transport. He succeeded, and today containers are a key element of global trade. The vast majority of goods transported abroad are shipped in containers that are loaded and unloaded at specialised ports and terminals around the world. Standardisation also includes the introduction of automated container handling systems, which further increase efficiency and reduce costs (Levinson 2006). The logistics of producing, moving and selling the contents of containers is comparable all over the world. The con- 16 tainer is therefore effectively a “homogenizing machine” (Eriksen 2014: 70) that is transforming the world, perhaps even more than many other high-tech devices. 3. CONTAINER LIFE IN PETRINJA, CROATIA The study presented in this paper is based on ethnographic research conducted after the 2020 earthquake in Petrinja, Croatia. The main part of the field research was conducted in March 2023, when the author of this paper contacted residents of container settlements and individual container houses through interviews and participant observation. The location was selected for the research as part of a wider study of isolated people and communi-ties in Slovenia and Croatia. The location became particularly important for the research as a part of Croatia was hit by a natural disaster in 2020. On 29 December that year, the region, which was already struggling, was hit by a devastating earthquake measuring 6.2 on the Richter scale. The epicenter was about three kilometers from Petrinja, Croatia, a small town with a population of around 15,000. The consequences of the earthquake were devastating, with more than 40,000 houses and infrastructure facilities in the broader region of Banija damaged or destroyed, and the total financial damage estimated at €5.5 billion (Kersten-Pejanić 2022: 103). The earthquake, which destroyed towns, villages, and hamlets in Banija, forced many locals to seek shelter in temporary dwellings – either in containers placed in front of their homes or in container settlements built in Petrinja, Glina, and Sisak. At the beginning of 2021, three large settlements resembling refugee camps and similar structures erected in crisis areas around the world sprang up on the outskirts of Petrinja. The settlements were built on vacant lots, many of which have connectivity and accessibility issues, mainly due to dilapidated roads. The next problem for the residents of the settlements was overcrowding, as individuals often had to share their place with other people. Figure 1: Consequences of the earthquake in Petrinja (photo credit: Dan Podjed, March 2023) Containers have – as presented more in-depth in other publications (see, e.g., Peternel & Podjed 2024) – left their mark on the image of Petrinja, and the “outsiders” are greeted by a huge “homogenizing machine” when they arrive in the town and park next to a huge temporary building that had been erected a few months after the earth-quake to provide essential infrastructure for the residents of the container settlement: shops, restaurants, cafés... The scene is even more surprising because of the design of the complex, which could have been found anywhere, as it resembles similar “non-places” (Augé 1992) elsewhere in the world. The complex, somewhat paradoxically and ironically named the Center of New Life (Croatian: Centar novog života), was built in September 2021, nine months after the earthquake. It consists of 168 shipping containers and houses 50 companies, which employed 17 163 people at the time of the study. The building, painted in a striking red, black, and white pattern, was soon un-officially named by locals Šarengrad, meaning “Colorful City.” Some found the structure interesting and attractive when it was first erected, while others insisted that they would never set foot in such a grotesque building, as it did not fit into their home environment. Figure 2: Center of New Life, constructed of 168 shipping containers, in Petrinja, Croatia (photo credit: Dan Podjed, March 2023) 4. OTHER EXAMPLES OF CONTAINERIZATION What if our lives have become “container lives” – even beyond the post-earthquake sites and the physical reali-ty? Perhaps the online social media have made people isolated in different digital “containers,” which Eli Pariser (2012) calls “filter bubbles.” In them, people mainly see themselves and their own problems, forgetting about the world beyond the mental barrier designed to “filter” information. When we start perceiving the world from such a perspective, the container is in fact turned in the central metaphor of the present world. Things we use and eat come to us in containers. We throw things away when they have served their purpose, and food leftovers that we do not eat also end up in containers. People who find themselves in distress and have no roof over their heads after an earthquake or other natural disaster are put in containers. Even the construction workers who come from abroad to help rebuild infrastructure after a disaster find shelter in them. However, containers are not just grim dwellings where people find shelter in times of crisis. They are also objects of desire, especially when they are converted into “mobile homes” where families can enjoy their holidays by the sea. In Qatar, shipping containers were even used to build a magnificent football stadium, which hosted the 2022 World Cup. The central idea behind the construction of this facility, called Stadium 974, was that it would be dis-mantled after the event and the containers used for other temporary structures and buildings. (The number 974 in the name of this huge structure was not chosen at random, as it represents the number of shipping containers used to build it, and is also Qatar’s international dialing code.) The shipping container was therefore a central, but perhaps overlooked, metaphor for an event watched by a billion and a half people around the world. 18 Figure 3: Stadium 974 during the 2022 FIFA World Cup, Doha, Qatar (photo credit: Wikipedia, CC BY-SA 4.0) 5. CONCLUSION After all, containers are also a kind of everyday dwelling, i.e., apartments and houses that are becoming increas-ingly standardized and uniform, where people are often confined and isolated, even though they are actually next to each other. In apartments in reinforced concrete blocks and high-rises, they can hear their neighbors, and the whole building echoes when someone is renovating their apartment and drilling into the walls with a power tool. The constitutive idea behind them is that people can be physically close to each other, but remain isolated and anonymous, or – as Karl Marx argued – alienated from the community and work, which divides the individual himself and transforms him into an automatic mechanism for performing a partial task (Marx 1961: 410). Such individualisation leads not only to the automatization of work, but also to general alienation – as if we were all locked in boxes, making even those who are physically close to us seem like strangers (cf. Krašovec 2021 with a similar discussion of alienation from work and existence, as well as the “alienization of capital” in the age of new technological solutions). From this perspective, containers could also predict the future. Perhaps in the era of late capitalism, which is turn-ing into “technofeudalism” (Varoufakis 2023), such dwellings represent ideal units for living and working, which can take place entirely within a container. As mentioned, containers bring people things and food, and then they throw their trash into containers, and in a container called a coffin, they leave this world. This is another reason why life is becoming increasingly containerized – and consequently isolated within the pre-defined boundaries. 19 6. ACKNOWLEDGEMENTS: The paper is a result of the research project J6–4610 and the research program P6–0088, supported by the Slo-venian Research and Innovation Agency. Preliminary results presented in the paper were published in Slovenian language in the author‘s book Crisolation (Podjed 2024). 7. REFERENCES: Augé, M. 1992. Non-places: Introduction to an Anthropology of Supermodernity. Le Seuil: Verso. Eriksen, T. H. 2014. Globalization: The Key Concepts (2nd edition). London & New York: Bloomsbury. Kersten-Pejanić, R. 2022. “The Good, the Bad, and the Needy: Discourses of Helpfulness after the 2020 Earthquakes in Croatia.” Comparative Southeast European Studies 70 (1): 103–124. Krašovec, P. 2021. Tujost kapitala [Alien Capital]. Ljubljana: Sophia. Levinson, M. 2006. The Box: How the Shipping Container Made the World Smaller and the World Economy Bigger. Princeton (NJ): Princeton University Press. Marx, K. 1961 (1867). Kapital – Kritika politične ekonomije: Proces produkcije kapitala (volume 1, book 1). Ljubljana: Cankarjeva založba. Pariser, E. 2012. The Filter Bubble: How the New Personalized Web Is Changing What We Read and How We Think. New York: Penguin Books. Peternel, L. & Podjed, D. 2025. “Container Life in Post-earthquake Croatia.” Focaal (online first): 1–14. Available at: https://doi.org/10.3167/ fcl.2024.100702 Podjed, D. 2024. Krizolacija: Znanstveno branje o izoliranih ljudeh [Crisolation: Scientific Reading about Isolated People]. Ljubljana: Založba ZRC. Varoufakis, Yanis. 2023. Technofeudalism: What Killed Capitalism. London: The Bodley Head. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Dan Podjed Research Center of the Slovenian Academy of Sciences and Arts Institute of Slovenian Ethnology Novi trg 2 1000 Ljubljana, Slovenia +386 31 820 198 dan.podjed@zrc-sazu.si 20 ORAL PRESENTATION INNOVATING THE SKIES: PIPISTREL’S COMPOSITE REVOLUTION WITH TEXTILES, ADVANCED MATERIALS AND 3D TECHNIQUES IN AVIATION Ingrid Heuffel Berginc Pipistrel, d.o.o., Slovenia The revolution of new technologies and development is reflected in Pipistrel’s efforts to push boundaries. One of the company’s greatest achievements is the Velis Electro, the world’s first certified electric aircraft. Since 2022, Pipistrel has been part of Textron Inc., enabling further advancements in cutting-edge technologies, high-quality systems, and sustainable aviation solutions. A key milestone in 2025 marks progress in the development of advanced, sustainable, and multifunctional unmanned aerial systems with the Nuuva V300 (eVTOL UAV)—a revolutionary autonomous electric vertical takeoff and landing (eVTOL) aircraft. Designed for cargo logistics and delivery, it offers 10 times greater efficiency than today’s helicopters, requires no runways, and enhances safety and reliability through Pipistrel’s certified electric motors. Humanity has always faced risks, and unidentified, overlooked, or poorly managed risks often lead to errors. In aviation, where technological processes are highly complex and follow precisely defined timeframes, even the smallest mistake can have serious consequences. At Pipistrel, we are acutely aware of this, which is why we strive for the highest safety standards, continuous technological improvements, and meticulously controlled procedures. Our goal is to ensure that innovations in sustainable aviation not only drive progress but also guarantee the highest possible level of safety for everyone involved in air traffic. An essential tool for enhancing safety culture and quality at Pipistrel is our Safety Management System (SMS), which enables early risk detection and error management. Additionally, our Quality Assurance System, aligned with EASA aviation regulations, ensures compliance with industry standards. To achieve the required quality standards in aircraft component manufacturing (fuselage, wings, etc.), Pipistrel uses various advanced materials. Understanding material structure and properties and conducting quality tests are critical. The materials used in Pipistrel aircraft are modern composite materials—consisting of two or more different materials at a macroscopic level. These materials offer low weight, high strength, dimensional stability under extreme conditions, and corrosion resistance. The two main production technologies used are: wet lamination and prepreg technology. Prepreg (pre-impregnated fibers) are composite materials where fibers are already impregnated with resin in a controlled environment. This process ensures higher repeatability, improved mechanical performance, and reduced risk of errors as the materials cure under high temperature and pressure in an autoclave. Prepreg is commonly used in high-performance aircraft and complex structures. To ensure quality control, both destructive and non-destructive testing methods are employed during the composite part manufacturing process. A crucial quality characteristic is the adhesion between the matrix and the reinforcement element, which ensures the final strength of the composite product. In addition to composite parts, 3D printing technology is also used in Pipistrel aircraft components. HP’s Multi Jet Fusion (MJF) technology has revolutionized design and production processes, enabling the manufacture of complex components that would be impossible to create using traditional methods. 21 3D-printed parts are mechanically equivalent to injection-molded plastic, isotropic, waterproof, and airtight, without requiring additional tooling—a 3D model is sufficient. The key advantage of 3D printing is the ability to produce complex parts in a single piece, simplifying manufacturing and reducing aircraft production time. Other benefits include weight savings, increased precision, improved aesthetics, and the elimination of additional subassembly steps. Overall, 3D printing enhances the quality, durability, and adaptability of aircraft components, representing a significant step forward in modernizing aviation manufacturing. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Ingrid Heuffel Berginc Pipistrel d.o.o. Goriška cesta 50a 5270 Ajdovščina Slovenia info@pipistrel-aircraft.com 22 INVITED LECTURES 29–30 May 2025, Ljubljana, Slovenia SESSION-INVITED LECTURE ORAL PRESENTATION BETI‘S TRANSFORMATION FROM A LABOUR–INTENSIVE TO A DEVELOPMENT–AND INNOVATION–ORIENTED COMPANY Petra Kovačič1 1BETI textile industry d.o.o., Slovenia Abstract: Beti is a leading European manufacturer of sustainable and functional dyed yarn. The beginnings of the company Beti date back to the year 1959. Over the years, Beti has specialized in the production of polyamide and polyester yarn. Beti yarn is exported all over the world from Europe, North America, North Africa, Middle East and even to Asia. Besides the traditional markets of Italy, France and United States, we have strengthened our presence in Central and Northern Europe in the last years. The main users of Beti‘s yarn are manufacturers in the sportswear, fashion, technical and medical textile industries who are committed to achieving sustainability goals. Leading sports and fashion brands are setting ambitious sustainability targets, such as reaching 50% sustainable product lines by the end of 2025. Beti‘s development activities are strategically aligned with these development objectives, in order to support clients‘ sustainability efforts while enhancing competitive market position. The most recent research projects are focused on development of: i) yarn with a low carbon footprint to reduce water, energy, dyestuff and chemical consumption, ii) advanced functional yarn for smart textiles, iii) yarns for thermo-regulation, iv) a distinctive collection of Slovenian sustainable underwear considering circular design principles. In Beti we are aware that every small innovation in processes, products and technologies contributes to more efficient, sustainable, and value-driven future. With everyday research activities Beti is thus transitioning from a labor-intensive to a development- and innovation oriented company. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Petra Kovačič BETI textile industry d.o.o. Tovarniška cesta 2 8330 Metlika, Slovenia +386 7 36 38 128 petra.kovacic@beti.si 25 29–30 May 2025, Ljubljana, Slovenia SESSION-INVITED LECTURES ORAL PRESENTATION INNOVATIVE MATERIAL AND ETHICS EXPLORATION IN FASHION: THE WORK OF TINA GORJANC Tina Gorjanc Safhalter1 1Freelance designer, Slovenia Abstract: Wearable design is evolving alongside other design disciplines by increasingly integrating scientific methods to tackle urgent ethical and sustainability challenges. Tina Gorjanc’s work exemplifies this transforma-tive shift, blending biotechnology and scientific data analysis with experimental material innovation to challenge conventional materials and spark critical discussions on design-related ethics. Through her projects, Gorjanc questions traditional perceptions of sustainability and ethical design, pushing the boundaries of what is possible, implementable or acceptable. This presentation seeks to illuminate her work’s methodology and design thinking, showcasing how design within planetary boundaries can redefine creativity, responsibility, and innovation in the modern design landscape. Keywords: Holistic Design, Material Innovation, Critical Fashion 1. INTRODUCTION Tina Gorjanc critiques the idea of “silver bullet” solutions in sustainable fashion and advocates for ethically sour-ced and environmentally appropriate materials tailored to specific contexts. Her designs challenge industry nor-ms, promoting higher ethical standards and holistic sustainability without greenwashing, which is becoming in-creasingly particularly important in an industry often criticized for its dependence on unsustainable resources, exploitative labour, and profit-driven practices. 2. COLLABORATION BETWEEN SCIENCE AND DESIGN A cornerstone of Gorjanc‘s work is her ability to bridge the creative and scientific domains through effective col-laboration with scientists. Her partnerships with material scientists and researchers have allowed her to explore experimental technologies that might otherwise remain confined to laboratories. By adopting this interdisciplinary approach, she advances material innovation and underscores the role of design as a tool for science communi-cation. Gorjanc demonstrates how designers can act as mediators, translating complex scientific concepts into tangible artefacts that engage the public and provoke critical debate. Figure 1: Pure Human Documentary poster 26 29–30 May 2025, Ljubljana, Slovenia 2.1 Pure Human The Pure Human project exemplifies Gorjanc‘s commitment to ethical and innovative material design. By creating speculative artefacts—such as leather bags and jackets derived from human genetic material—she explores how biotechnology can produce bespoke materials while addressing provocative ethical and legal questions around ownership and the commodification of human biology. Figure 2: Tattooed leather jackets mimic inked skin alteration techniques Figure 3: The pigmented product exploits the ability of the TYR gene to promote the production of the pigment melanin. The stimulation of the gene’s performance is achieved with biological agents. Depending on the amount of the applied agent, the accumulated melanin can appear on a more minor (freckles) or larger (moles) scale. While controversial, Pure Human has drawn critical attention to how biotechnology could transform material pro-duction, particularly in industries like fashion, which heavily rely on animal-based resources. The project redefines traditional notions of materiality, encouraging designers and consumers to reconsider the origins and ethical im-plications of the materials they use and wear. 27 29–30 May 2025, Ljubljana, Slovenia Figure 4: Pure Human material-making process The project operates outside traditional commercial frameworks and relies on speculative design principles. This approach assesses how effectively Pure Human navigates the space between current realities and potential fu-ture scenarios. In doing so, Gorjanc challenges entrenched assumptions about material use and product roles in everyday life, fostering a reimagining of materials in a more ethically conscious future. Figure 6: Pure Human whole project display 2.2 Phylogenetic Atelier With Phylogenetic Atelier, Gorjanc redefines the future of bio-based design. Her participation in renowned events such as Science Gallery Dublin, Artez 2018, and the London Design Festival highlights her commitment to brid-ging biotechnology and mainstream conversations. These projects push the boundaries of innovation by chal-lenging conventional material lifecycles tied to specific timelines. Using cutting-edge scientific techniques akin to those in science fiction, Phylogenetic Atelier showcases bio-fabricated materials as transformative solutions to critical issues like resource scarcity. Figure 7: Phylogenetic Atelier whole project display In collaboration with Revive & Restore, a California-based research lab focused on reviving extinct species, Gorjanc explores sustainable approaches to lab-grown leather. One notable initiative involves recreating „de-ex-tinct“ passenger pigeon leather—achieved without rebounding the extinct bird for over 100 years. 28 29–30 May 2025, Ljubljana, Slovenia Figure 8: Passenger pigeon blueprint This project allows audiences to critically examine the potential impacts of such designs before their commercial introduction, guiding development and aligning with sustainable and ethical objectives. Figure 9: Glove from pigeon leather, which replicates the de-extinct pigeon skin 2.3 Ceros Beyond speculative design, Gorjanc is committed to raising public awareness about artificially inflated material values and their broader implications. Featured in publications like Dezeen, The Guardian (Jones,2016) and Vice Media (Cole, 2017), she addresses misconceptions about biotechnological processes, tackling fears of „playing God“ and the ethical challenges of genetic modification and artificial material creation. Ceros represents a transition from speculation to tangible innovation, demonstrating how dark design can foster positive creativity by addressing enduring challenges. During the COVID-19 pandemic, Gorjanc developed a biologically identical alternative to rhino horn in her makeshift home studio, using readily available chemicals. This project critiques the luxury market’s obsession with rhino horn while exposing the ethical issues surrounding wildlife trafficking. 29 29–30 May 2025, Ljubljana, Slovenia Figure 10: Ceros material sample By sparking thoughtful discourse, Ceros invites viewers to reflect critically on these controversies, fostering curio-sity about laws, political systems, ethics, values, and the broader implications of material culture. It demonstrates how design can be critical for envisioning a more ethical and socially conscious future. Figure 11: Beaded bracelet from Ceros material Figure 12: Grinding down bracelet beads for consumption, believed to cure disease in Chinese medicine 30 29–30 May 2025, Ljubljana, Slovenia 3. VISION FOR THE FUTURE OF DESIGN Gorjanc envisions a future where materials are sustainably sourced and designed to integrate seamlessly into both natural ecosystems and commercial systems. To achieve this, she adopts a multilayered approach. Along-side her provocative conceptual projects, she has launched a creative studio and consultancies that offer more practical, tangible solutions for immediate implementation. 3.1 Material Libraries And Resources For Other Designers As a permanent Learning Department associate at ITS Arcademy—the Museum of Art in Fashion in Trieste—and through collaborations, including mentoring students from London’s fashion universities, Gorjanc actively shares her expertise in innovative material design. She focuses on advancing material fabrication methods that reduce reliance on nonrenewable resources while delivering high-performance alternatives. By considering the entire lifecycle of materials—from creation to disposal—Gorjanc curates bespoke material lib-raries for institutions and individuals. This process includes defining sustainable terminology, categorizing areas of interest, and vetting material suppliers. Her work challenges designers to adopt a holistic, systems-thinking approach to material innovation. Gorjanc’s vision aligns with regenerative design principles, where materials are viewed not merely as products but as interconnected components of broader ecological systems. Her efforts encourage designers to embrace sustainability and creativity in tandem. 3.2 Critical Animal The creative studio operates on the foundation of the consumer vs. citizen paradox, which highlights the dis-connect between discussing societal issues as responsible citizens and acting as consumers who shape reality through their purchasing habits. The studio bridges expert knowledge with the public‘s struggle to navigate infor-mation overload, fostering dialogue and critical engagement around ethical and sustainable uses of animal-based materials. Gorjanc’s studio adopts a multifaceted approach to design. It collaborates with one of the world’s largest leather trade shows to repurpose deadstock, spearheads recycling initiatives, and creates designs that connect materials to their origins through texture and shape. Additionally, the studio focuses on designing customizable, interchan-geable objects, encouraging consumers to adapt or modify items instead of discarding them for new ones. This approach reduces waste and challenges traditional consumption patterns, promoting a more sustainable, mindful relationship with materials. Figure 13: Crock bag 31 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSION Tina Gorjanc’s work showcases the transformative power of design when guided by ethics, innovation, and a sen-se of responsibility. She challenges students and emerging designers to push beyond traditional boundaries and explore the vast potential of materials, demonstrating that design is not only about creating aesthetically pleasing products but also about addressing real-world challenges like resource scarcity and ethical dilemmas. Through projects like Pure Human, Phylogenetic Atelier, and Ceros, Gorjanc encourages rethinking the relation-ship between design, science, and society. Her work provokes ideas and invites the public to explore speculative concepts that can drive meaningful change. She emphasizes that a designer’s role is to challenge conventions, question assumptions, and lead discussions on issues that shape the future. By embracing interdisciplinary thinking and a holistic approach, designers can redefine materiality, create sustai-nable solutions, and contribute to an ecosystem where products are not merely objects but integral parts of a more ethical and sustainable world. Gorjanc’s vision calls us to think critically, use design as a tool for positive change, and take responsibility for creating with purpose. 5. REFERENCES Mitrović, I., Auger, J., Hanna, J., Helgason, I. (2019) ‘Speculations: Beyond Human-Centered Design’, in Beyond Speculative Design: Past – Present – Future, pp. 207-210. Split: SpeculativeEdu; Arts Academy, University of Split. Beaussart , M. (2019) ‘The self-donor workshop’ in HIGGS, Issue 3. London: Higgs Beaussart , M. (2019) ‘Phylogenetic Atelier’, in HIGGS, Issue 2. London: Higgs Beaussart , M. (2019) ‘Pure Human 0.01’, HIGGS, Issue 1. London: Higgs Dustman, E. A. (2017) ‘Art + Science | Culture’, E-Squared Magazine, Issue 3. SSN 2474-3984. Guttridge-Hewitt M. (2017) ‘Future Forecast’, in Design Exchange Magazine, Issue 14. Lončar, T. (2024) ‘In Search of a Better Future: Designer Profile’, Vogue Adria, March issue. Studio FranklinTill (2018) Viewpoint #41 - The Tactility Issue, pp.39 Gorjanc, T., Nicolaides, N. (2019) ‘Harvest’, MLitt Curatorial Practice, Glasgow School of Art. Gorjanc, T. (2019) ‘Searching For The New Luxury’, Artez Journal: Fashion Colloquium, Artez University Arnhem. Berden, B. (2016) ‘Pure Human: Leather Alternatives Inspired by Biological Systems’, Trend Tablet. Available at: https://www.trendtablet. com/48147-pure-human-by-tina-gorjanc/ (Accessed: 04 November 2024). Cole, S. (2017) ‘The Future of Textiles: Biofabrication and Innovation’, Vice Media. Available at: https://www.vice.com/en/article/mbz54v/the-future-of-textiles-tina-gorjanc (Accessed: 04 November 2024). Delmage, L. (2019) ‘Are We Playing God Too Much?’, Metal Magazine. Available at: https://metalmagazine.eu/post/tina-gorjanc-are-we-playing-god-too-much (Accessed: 04 November 2024). Jones, J. (2016) ‘Reimagining Materials: The Work of Tina Gorjanc’, The Guardian. Available at: https://www.theguardian.com/artanddesign/ tina-gorjanc-bio-design (Accessed: 04 November 2024). Mitrović, M. (2021) ‘Interview with Tina Gorjanc: Exploring the Intersection of Fashion and Biotechnology’. Available at: https:// speculativeedu.eu/interview-tina-gorjanc/ (Accessed: 04 November 2024). Paton, E. (2016) ‘Emerging Biodesign Trends’, New York Times. Available at: https://www.nytimes.com/tina-gorjanc-bio-design (Accessed: 04 November 2024). Rodríguez Fernández, C. (2019) ‘Self-Donor Workshop: Creating Biodesign Solutions’, Metal Magazine. Available at: https://metalmagazine.eu/en/post/interview/tina-gorjanc (Accessed: 04 November 2024). Tucker, E. (2016) ‘The Rise of Biodesign’, Dezeen. Available at: https://www.dezeen.com/tina-gorjanc-biodesign (Accessed: 04 November 2024). Wharry, J. (2019) ‘Tina Gorjanc Interview: Are We Pushing the Boundaries of Design?’ Available at: https://www.geraldinewharry.com/ getinspired/tina-gorjanc-interview-xt4kt (Accessed: 04 November 2024). Gorjanc, T. (2016) Exploring the Intersection of Design and Biotechnology: New Materials for Sustainable Fashion. PhD thesis, Central Saint Martins, University of the Arts London. Pfeiffer, K. (2024) Redeeming Making? Biodesign and the Hope for Better Production. PhD Thesis, University College London. Submitted for Doctor of Philosophy 13 November 2023, Corrected 4 March 2024. 32 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHOR Corresponding author: Tina Gorjanc Safhalter Education in the field of culture and art Tina Gorjanc Šafhalter s.p. Bernetičeva ulica 2, 6000 Koper, Slovenia +38668632170 gorjanc.tina@gmail.com 33 TEXTILE FIBERS 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION ANALYSIS OF SILKWORM BOMBYX MORI L. COCOONS 29–30 May 2025, Ljubljana, Slovenia MADE AFTER FLAT SPINNING Tatjana Rijavec1, Alenka Šalej Lah1 and Rebeka Lucijana Berčič2 ANALYSIS OF SILKWORM 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Bombyx mori L. COCOONS MADE AFTER 2University of Ljubljana, Veterinary Faculty, Slovenia FLAT SPINNING Abstract: The silkworm Bombyx mori L. normally produces a three-dimensional cocoon to protect itself during 1 Tatjana RIJAVEC , Alenka ŠALEJ LAH 1 , Rebeka Lucijana BERČIČ 2 the metamorphosis to pupa and moth. Such normal cocoons (NC) differ from cocoons made by caterpillars after they are included in flat spinning where they extrude major part of liquid silk. In this preliminary study of silkworm 1 University of Ljubljana, Faculty of Natural Sciences and Engineering flat-spinning process the silkworm larvae were enabled to naturally complete their life cycle after flat spinning. 1 University of Ljubljana, Veterinary Faculty More than 60% of the live larvae completed their life cycle with the formation of cocoons after three days of flat spinning. The analysis of these cocoons (AFSCs) shows that silkworms extruded (produced) about 0.35 g silk/ Abstract: The silkworm caterpillar Bombyx mori L. normally produces a three-dimensional cocoon to protect larvae after flat spinning and about 0.24 g/insect when they firmed cocoons. itself during transformation to pupa and moth. Such normal cocoons (NC) differ from cocoons made by caterpillars after they are included in flat spinning where they extrude major part of liquid silk. In this preliminary study of silkworm flat-spinning process the caterpillars were enabled to naturally complete their life cycle after Keywords: flat spinning. More than 60% of alive caterpillars after three days of flat spinning finished their life cycle with cocoon shape, effective rate of rearing, silk shell, silk floss. making cocoons. The analysis of these cocoons (AFSCs) show that caterpillars extruded about 0.35 g silk/insect after flat spinning and about 0.24 g/insect when they firmed cocoons. Keywords: cocoon shape, effective rate of rearing, silk shell, silk floss. 1. INTRODUCTION The silkworm Bombyx mori L. normally produces a three-dimensional cocoon to protect itself during transforma 1 INTRODUCTION - tion to pupa and moth. Such cocoons are usually referred to as normal cocoons (NC). When the is placed on a The silkworm caterpillar Bombyx mori L. normally produces a three-dimensional cocoon to protect itself during flat surface, it deposits the liquid silk jet on it, forming a two-dimensional structure named as a flat cocoon (FC). transformation to pupa and moth. Such cocoons are usually called normal cocoons (NC). When the caterpillar The possibility of the formation of FC by the Bombyx mori L. has attracted the interest of textile designers (Essig, is placed on a flat surface, it deposits the liquid silk jet on it, forming a two-dimensional structure named as a 2025). FC is a kind of "laid scrim", in which the straightened threads are laid one on top of the other in a specific flat cocoon (FC). The possibility of forming FC by Bombyx mori L. caterpillars has attracted the interest of pattern and glued together, rather than intertwined as in weaving or knitting. Due to the biocompatibility of fibroin textile designers (Essig, 2025). FC is a kind of "laid scrim", where the straightened threads are laid one on top and sericin, FCs are also interesting for technical applications, especially in the medical field (Wu et al., 2022, of the other in a specific pattern and glued together, rather than intertwined as in weaving or knitting. FCs are Wang et al., 2024). also interesting for technical applications, especially in the medical field (Wu et al., 2022, Wang et al., 2024), due to the biocompatibility of fibroin and sericin. This is a preliminary study on optimizing the silkworm flat-spinning process, with the goal of enabling the natural completion of the silkworm life cycle after flat spinning. This is a preliminary study on optimizing the silkworm flat-spinning process, with the goal of enabling the Therefore, we let the moth in a cocoon to secrete a liquid to partly dissolve the cocoon and exit from it. The studied cocoons were made after flat spinning – we called them natural completion of the silkworm life cycle after flat spinning. Therefore, we let the moth in a cocoon to secrete after-flat-spinning cocoons, AFSCs. On the Figure 1 moth that has left the AFSC through the opening (brown area) a liquid to partly dissolve the cocoon and exit from it. The studied cocoons were made after flat spinning – we (a), a cocoon with silk floss (b), a cleaned cocoon (c) and an exuvia of levitation of pupae (left) and caterpillar called them after-flat-spinning cocoons, AFSCs. On the Figure 1 moth that has left the AFSC through the (middle) extracted from the cut cocoon and silk shell (right) (d) are shown. opening (brown area) (a), a cocoon with silk floss (b), a cleaned cocoon (c) and an exuvia of levitation of pupae (left) and caterpillar (middle) extracted from the cut cocoon and silk shell (right) (d) are shown. a) b) c) (d) Figure 1 Figure 1 : Moth (a), after-flat-spinning cocoon (AFSC) (b), and its parts (c, d). : Moth (a), after-flat-spinning cocoon (AFSC) (b), and its parts (c, d). 2 EXPERIMENTAL 2.1 Materials In October 2024, Prof. Marija Jenko created two artistic sculptures with Bombyx mori L. caterpillars (Jenko, four cardboard boxes with mulberry leaves and branches (Box 1–Box 4 in Figure 2); we also received a certain 35 2025). After three days, she and Mojca Košir stopped the silkworms from spinning and transferred them into number (70) of caterpillars and placed them in individual cardboard and plastic compartments (Box 5 in Figure 2) to pupate and transform into butterflies, completing their natural life cycle (Figure 3). 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL 2.1 Materials The genetic material (eggs of an European silkworm hybrid) was provided by the Institute of Sericulture, CREA, Padova, Italy. Silkworm eggs were hatched and larvae reared until the end of 5th instar by Rebeka Lucijana Berčič, who transported them to NTF UL just before the start of pupation. In October 2024, Prof. Marija Jenko created two artistic sculptures with silkworm Bombyx mori L. (Jenko, 2025). After three days, she and Mojca Košir stopped the larvae from spinning and transferred them into four cardboard boxes with mulberry leaves and twigs (Box 1–Box 4 in Figure 2); we also received a certain number (70) of larvae and placed them in individual card 29–30 May 2025, Ljubljana, Slovenia -board and plastic compartments (Box 5 in Figure 2) so that they would pupate and transform into butterflies, thus completing their natural life cycle (Figure 3). AFSC - Box 1 AFSC - Box 2 AFSC - Box 3 AFSC - Box 4 AFSC - Box 5 Figure 2: After-flat-spinning of silkworms Bombyx mori L. in boxes. Figure 2: After-flat-spinning of silkworms Bombyx mori L. in boxes. Box 1 Box 2 Box 3 Box 4 36 29–30 May 2025, Ljubljana, Slovenia AFSC - Box 1 AFSC - Box 2 AFSC - Box 3 AFSC - Box 4 AFSC - Box 5 Figure 2: After-flat-spinning of silkworms Bombyx mori L. in boxes. Box 1 Box 2 Box 3 Box 4 Box 5 Figure 3: After-flat-spinning cocoons (AFSC), moths, pupas, dead caterpillars, and exuviahs in boxes. Figure 3: After-flat-spinning cocoons (AFSC), moths, pupas, dead larvae, and exuviahs in boxes. 2 2.2 Methods After about four weeks, the boxes were opened and analysed their contents: butterflies, larvae, cocoons (AFSC) and incomplete cocoons were sorted and photographed (Figure 3). The outer floss layer was removed from each AFSC, and then the dimensions of the clean AFSCs were measured at the thickest and thinnest points with a cal-liper, each clean AFSC was weighed on an analytical balance, the AFSC was opened by using surgical scissors, and the silk shell separated from the remains of the insect. The silk shells were also weighted and assessed the shapes of the AFSCs. 37 2.2 Methods (AFSC), and incomplete cocoons were sorted and photographed (Figure 3). From each AFSC was removed 29–30 May 2025, Ljubljana, Slovenia the outer floss layer, and then the dimensions of clean AFSCs were at the thickest and thinnest points After about four weeks the boxes were opened and analysed their contents: butterflies, caterpillars, cocoons scissors, and separated the silk shell from the remains of the insect. The silk shells were also weighted and After about four weeks the boxes were opened and analysed their contents: butterflies, caterpillars, cocoons assessed the shapes of the AFSCs. (AFSC), and incomplete cocoons were sorted and photographed (Figure 3). From each AFSC was removed measured with a calliper, weighed each clean AFSC on an analytical balance, opened AFSC by using surgical 2.2 Methods Calculation of an effective rate of rearing AFSCs by number: the outer floss layer, and then the dimensions of clean AFSCs were at the thickest and thinnest points Calculation of an effective rate of rearing AFSCs by number: measured with a calliper, weighed each clean AFSC on an analytical balance, opened AFSC by using surgical scissors, and separated the silk shell from the remains of the insect. The silk shells were also weighted and 𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁 𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 assessed the shapes of the AFSCs. = × 100 (%) (1) 𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁 𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑁𝑁𝑁𝑁 𝑐𝑐𝑐𝑐𝑎𝑎𝑎𝑎𝑐𝑐𝑐𝑐𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑐𝑐𝑐𝑐𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑁𝑁𝑁𝑁𝐴𝐴𝐴𝐴 𝑁𝑁𝑁𝑁𝑜𝑜𝑜𝑜𝑎𝑎𝑎𝑎𝑁𝑁𝑁𝑁𝑚𝑚𝑚𝑚 𝑎𝑎𝑎𝑎𝑖𝑖𝑖𝑖𝑐𝑐𝑐𝑐𝑜𝑜𝑜𝑜 𝑁𝑁𝑁𝑁𝑜𝑜𝑜𝑜𝑏𝑏𝑏𝑏𝑁𝑁𝑁𝑁𝐴𝐴𝐴𝐴 For statistical analysis, one-way ANOVA was used (Statgraphics Centurion XV, Version 15.1.02). Calculation of an effective rate of rearing AFSCs by number: For statistical analysis, one-way ANOVA was used (Statgraphics Centurion XV, Version 15.1.02). 3 RESULTS AND DISCUSSION 𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁 𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴 𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 = × 100 (%) (1) 𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁 𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑁𝑁𝑁𝑁 𝑐𝑐𝑐𝑐𝑎𝑎𝑎𝑎𝑐𝑐𝑐𝑐𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑐𝑐𝑐𝑐𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑁𝑁𝑁𝑁𝐴𝐴𝐴𝐴 𝑁𝑁𝑁𝑁𝑜𝑜𝑜𝑜𝑎𝑎𝑎𝑎𝑁𝑁𝑁𝑁𝑚𝑚𝑚𝑚 𝑎𝑎𝑎𝑎𝑖𝑖𝑖𝑖𝑐𝑐𝑐𝑐𝑜𝑜𝑜𝑜 𝑁𝑁𝑁𝑁𝑜𝑜𝑜𝑜𝑏𝑏𝑏𝑏𝑁𝑁𝑁𝑁𝐴𝐴𝐴𝐴 3. RESULTS AND DISCUSSION From 300 caterpillars 293 were involved in the flat-spinning process for the creation of artistic sculptures, of For statistical analysis, one-way ANOVA was used (Statgraphics Centurion XV, Version 15.1.02). From 300 larvae 293 were involved in the flat-spinning process for the creation of artistic sculptures, of which in five boxes (Figure 2). Seven (7) from 300 caterpillars were not included in the flat-spinning but were let to 3 RESULTS AND DISCUSSION make normal cocoons (NC), four of them were measured (data presented as NC). which 11 died during flat-spinning (3.75%), and 282 survived and were included in after-flat-spinning cocooning established average ERRn was 62.8%: min. 60% for Boxes 1 and 4 and max. 67% for Box 5. Shifa (Shifa, 2015) Mult-yel and Mult-wh races of silkworm Bombyx mori L in normal cocoon spinning prpcess. From survived 282 caterpillars transferred after flat-spinning into boxes (Figure 1) 177 caterpillars made cocoons (AFSCs). These data were used for calculation an effective rate of rearing of AFSCs by number states the lowest ERRn of 54.17% for Korea-3 and the highest ERRn 92.0% for Mult-yel and Mult-wh races of Under favourable conditions, a moth emerges from the cocoon and in a cocoon, shell remains only an exuvia. (ERRn) (Figure 4a): the established average ERRn was 62.8%: min. 60% for Boxes 1 and 4 and max. 67% silkworm Analysed remains of the insects in AFSCs from the Boxes 1, 2, 4 and 5 (Figure 4b) show that 73.3% moths Bombyx mori L in normal cocoon spinning process. for Box 5. Shifa (Shifa, 2015) states the lowest ERRn of 54.17% for Korea-3 and the highest ERRn 92.0% for left the AFSCs: from 66.7% (Box 1) to 87.5% (Box 4) where FSCs contained only exuviae. Data on insect Mult-yel and Mult-wh races of silkworm Bombyx mori L in normal cocoon spinning prpcess. Under favourable conditions, a moth emerges from the cocoon and in a cocoon, shell remains only an exuvia. remains in normal cocoons (NC) are not available, as NC are collected and dried for the pupae suffocated, to Analysed remains of the insects in AFSCs from the Boxes 1, 2, 4 and 5 (Figure 4b) show that 73.3% moths left stop the silkworm's life cycle. Our research offering a more humane approach to this insect, as it enables to Under favourable conditions, a moth emerges from the cocoon and in a cocoon, shell remains only an exuvia. the AFSCs: from 66.7% (Box 1) to 87.5% (Box 4) where FSCs contained only exuviae. Data on insect remains preserve the silkworm's life cycle. Spinning in boxes with mulberry branches and leaves proved to be Analysed remains of the insects in AFSCs from the Boxes 1, 2, 4 and 5 (Figure 4b) show that 73.3% moths in normal cocoons (NC) are not available, as NC are collected and dried for the pupae suffocated, to stop the comfortable for caterpillars but there was more opportunity for the emergence double AFSCs (made by two left the AFSCs: from 66.7% (Box 1) to 87.5% (Box 4) where FSCs contained only exuviae. Data on insect silkworm’s life cycle. Our research offers a more humane approach to this insect, as it enables to preserve the caterpillars) (Figure 5) with higher mass of AFSCs and silk shells. remains in normal cocoons (NC) are not available, as NC are collected and dried for the pupae suffocated, to silkworm's life cycle. Spinning in boxes with mulberry twigs and leaves proved to be beneficial for the caterpillars cocoons (NC), four of them were measured (data presented as NC). cocoons (AFSCs). These data were used for calculation an effective rate of rearing of AFSCs by number in five boxes (Figure 2). Seven (7) from 300 caterpillars were not included in the flat-spinning but were let to (ERRn) (Figure 4a): the established average ERRn was 62.8%: min. 60% for Boxes 1 and 4 and max. 67% make normal cocoons (NC), four of them were measured (data presented as NC). From survived 282 larvae transferred after flat-spinning into boxes (Figure 1) 177 larvae made cocoons (AFSCs). for Box 5. Shifa (Shifa, 2015) states the lowest ERRn of 54.17% for Korea-3 and the highest ERRn 92.0% for These data were used for calculation an effective rate of rearing of AFSCs by number (ERRn) (Figure 4a): the boxes (Figure 2). Seven (7) from 300 larvae were not included in the flat-spinning but were let to make normal From 300 caterpillars 293 were involved in the flat-spinning process for the creation of artistic sculptures, of From survived 282 caterpillars transferred after flat-spinning into boxes (Figure 1) 177 caterpillars made which 11 died during flat-spinning (3.75%), and 282 survived and were included in after-flat-spinning cocooning 11 died during flat-spinning (3.75%), and 282 survived and were included in after-flat-spinning cocooning in five but there were more opportunities for the emergence of double AFSCs (made by two caterpillars) (Figure 5) with 101 caterpillars (35.82%) of 282 all caterpillars included in flat spinning did not make AFSCs; they made only stop the silkworm's life cycle. Our research offering a more humane approach to this insect, as it enables to a higher mass of AFSCs and silk shells. silk floss, they died or transformed into pupa without making AFSCs and later to moth in the boxes. preserve the silkworm's life cycle. Spinning in boxes with mulberry branches and leaves proved to be comfortable for caterpillars but there was more opportunity for the emergence double AFSCs (made by two caterpillars) (Figure 5) with higher mass of AFSCs and silk shells. 101 larvae (35.82%) of 282 all larvae included in flat spinning did not make AFSCs; they made only silk floss, they died or transformed into pupa without making AFSCs and later to moth in the boxes. 101 caterpillars (35.82%) of 282 all caterpillars included in flat spinning did not make AFSCs; they made only silk floss, they died or transformed into pupa without making AFSCs and later to moth in the boxes. a) b) Figure 4: Effective rate of rearing AFSCs by number (ERRn) (a), and remains in AFSCs (b) a) b) 3 Figure 4: Effective rate of rearing AFSCs by number (ERRn) (a), and remains in AFSCs (b) Figure 4: Effective rate of rearing AFSCs by number (ERRn) (a), and remains in AFSCs (b) 3 38 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia NC and AFSCs naturally dried at room temperature were analysed. The mass of NC with a dead larvae was NC and AFSCs naturally dried at room temperature were analysed. The mass of NC with a dead caterpillar 0.4735 g, its shell 0.2132 g (45.03% of NC mass); the average mass of NCs with exuviae was 0.3128 g, of shell was 0.4735 g, its shell 0.2132 g (45.03% of NC mass); the average mass of NCs with exuviae was 0.3128 g, NC and AFSCs naturally dried at room temperature were analysed. The mass of NC with a dead caterpillar 0.2823 g (Figure 5). A lower casing weight may be the result of the larvae dying before the completion of the bur-of shell 0.2823 g (Figure 5). A lower casing weight may be the result of the caterpillar dying before the was 0.4735 g, its shell 0.2132 g (45.03% of NC mass); the average mass of NCs with exuviae was 0.3128 g, rowing process. completion of the burrowing process. Large differences in mass were found between AFSCs (Figure 5): mass of AFSCs was between 0.054 g and 1.464 g (average 0.315 g), mass of silk shell was between 0.064 g and 0.884 g (average 0.207 g). Extremely -tremely high masses are due to the double cocoons. The lowest masses were recorded in cocoons left by moths. high masses are due to double cocoons. The lowest masses were recorded in cocoons left by moths. Average 1.464 g (average 0.315 g), mass of silk shell was between 0.064 g and 0.884 g (average 0.207 g). Extremely The average mass of the exuviae (of pupa and larvae) were only 0.02 g. These cocoons were extremely thin and mass of exuviae (of pupa and caterpillar) were only 0.02 g. These cocoons were extreme thin and light with high masses are due to double cocoons. The lowest masses were recorded in cocoons left by moths. Average completion of the burrowing process. Large differences in mass were found between the AFSCs (Figure 5): the mass of the AFSCs was between 0.054 Large differences in mass were found between AFSCs (Figure 5): mass of AFSCs was between 0.054 g and g and 1.464 g (average 0.315 g), mass of silk shell was between 0.064 g and 0.884 g (average 0.207 g). The ex of shell 0.2823 g (Figure 5). A lower casing weight may be the result of the caterpillar dying before the light with silk shell of only 0.0717 g or thick and heavy with shell mass of 0.3151 g. Silk shell presented on average silk shell of only 0.0717 g or thick and heavy with shell mass of 0.3151 g. Silk shell presented on average mass of exuviae (of pupa and caterpillar) were only 0.02 g. These cocoons were extreme thin and light with 91.9% of these cocoons mass. This means that not only the amount of liquid silk in the glands is important for 91.9% of these cocoons mass. This means that not only is the amount of liquid silk in the glands important for silk shell of only 0.0717 g or thick and heavy with shell mass of 0.3151 g. Silk shell presented on average cocoon formation and the successful completion of the silkworm's life cycle, but that there are also other environ cocoon formation and the successful completion of the silkworm's life cycle, but there are also other -91.9% of these cocoons mass. This means that not only is the amount of liquid silk in the glands important for mental factors that stimulate or inhibit the silkworm's activity. environmental factors that stimulate or inhibit the silkworm's activity. cocoon formation and the successful completion of the silkworm's life cycle, but there are also other environmental factors that stimulate or inhibit the silkworm's activity. Figure 5 Figure 5: Distribution of silk shells and after flat spinning cocons (AFSCs) mass : Distribution of silk shells and after flat spinning cocons (AFSCs) mass The average length of cocoons was 30.7 mm, the minimum length was 24.99 mm, and the maximum length The average length of cocoons was 30.7 mm, the minimum length was 24.99 mm, and the maximum length Figure 5 : Distribution of silk shells and after flat spinning cocons (AFSCs) mass The average length of cocoons was 30.7 mm, the minimum length was 24.99 mm, and the maximum length was was 60.36 mm (Figure 6a). 60.36 mm (Figure 6a). was 60.36 mm (Figure 6a). A distinctive feature of the cocoon shape was its flatness, which was defined by the aspect ratio of the cocoon width (the quotient between the major and minor width of a cocoon). The closer the aspect ratio is to 1, the A distinctive feature of the cocoon shape was its flatness, which was defined by the aspect ratio of the cocoon A distinctive characteristic of the cocoon shape was its flatness, which was defined by the aspect ratio of the cocoon width more evenly thick the cocoon is, and higher values mean greater flattening of the cocoon. The best-formed width (the quotient between the major and minor width of a cocoon). The closer the aspect ratio is to 1, the (the quotient between the major and minor width of a cocoon). The closer the aspect ratio is to 1, the more evenly thick the cocoons were in Boxes 2 and 4, while the worst were in Box 1. We did not determine the reasons because we cocoon is, and higher values mean greater flattening of the cocoon. The best-formed cocoons were in Boxes 2 and 4, while the more evenly thick the cocoon is, and higher values mean greater flattening of the cocoon. The best-formed did not analyze the size of the boxes or the amount of leaves and branches in them. worst were in Box 1. The reasons for this could not be determined as we did not analyze the size of the boxes or the amount cocoons were in Boxes 2 and 4, while the worst were in Box 1. We did not determine the reasons because we of leaves and twigs in them. did not analyze the size of the boxes or the amount of leaves and branches in them. a) b) a) Figure 6: Dimensions of NC and AFSCs b) Figure 6: Figure 6: Dimensions of NC and AFSCs Dimensions of NC and AFSCs 4 4 39 29–30 May 2025, Ljubljana, Slovenia From the ANOVA statistical test (Table 1), it was confirmed that the place of post-flat cocoon formation has no significant influence in terms of the number of cocoons, but it has influence on cocoon mass. Since the P-value of the F-test is less than 0.05, it is statistically significant that minor is associated with lower cocoon shell mass. Table 1: ANOVA Dependent variable Factor F-ratio p-value Boxes Length of cocoons 1.11 0.4486 Boxes Major width 1.32 0.3046 Boxes Minor width 1.23 0.3818 Boxes Cocoon mass 16.97 0.0188 Boxes Shell mass 0.78 0.7153 Shell mass Length 1.65 0.1540 Shell mass Cocoon mass 7.40 0.0611 Shell mass Major width 1.96 0.0944 Shell mass Minor width 6.66 0.0012 4. CONCLUSION The main findings of the experiment are listed in the Table 2. Tin order to plan a successful flat spinning process, an analysis of the larvae before and after flat spinning should be included. At the end, it is also necessary to de-termine the quality and usability of the whole silk after the silkworm's life cycle is complete. Table 2: Summary of cocoon analysis made by post-flat cocoon formation Properties Values Number of alive larvae included in flat spinning 278 Number of after flat spinning cocoons (AFSCs) 181 Effective rate of rearing by number 63.67% Silk floss (all floss/floss per cocoon) 19.94 g/0.07 g Shells (all shells/shell per cocoon) 42.69 g/0.24 g Raw silk (all floss and shells/floss and shell per co- coon) 62.63 g/0.35 g 5. REFERENCES Jenko, M. 2025. “Sviloprejke, živa materija v umetniških procesih.” Tekstilec 68(SI2): 114−115. Shifa, K., Tilahun, A., Terefe, M., Ibrahim, A., Birtu, K., Menbere, S. 2015. “Evaluation of different strains of mulberry silkworms /Bombyx mori L. / for their adaptability and silk yield in Ethiopia”. Eth. J. Anim. Prod., 15(1)-2015:187-200. Wang, S., Wang, Y., Wang, Y., Liu, J., Liu, F., Dai, F., Li, J., and Li, Z. “Pollen-Modified Flat Silk Cocoon Pressure Sensors for Wearable Applications.” Sensors 24, no. 14 (July 19, 2024): 4698. https://doi.org/10.3390/s24144698. Wu, B., Tong, X., Cheng, L., Jiang, S., Li, Z., Li, Z., Song, J., and Dai, F. “Hybrid Membrane of Flat Silk Cocoon and Carboxymethyl Chitosan Formed through Hot Pressing Promotes Wound Healing and Repair in a Rat Model.” Frontiers in Bioengineering and Biotechnology, 10 (November 1, 2022). https://doi.org/10.3389/fbioe.2022.1026876. 40 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHOR Corresponding author: Co-author(s): Prof. dr. Tatjana Rijavec Assist. Prof. dr. Rebeka Lucijana Berčič Faculty of Natural Sciences Veterinary Faculty Gerbičeva ulica 60 and Engineering University of Ljubljana University of Ljubljana Department of Textiles 1000, Ljubljana, Slovenia Graphic Arts and Design rebekalucijana.bercic@vf.uni-lj.si +386 1 4779 240 Snežniška 5 1000, Ljubljana, Slovenia Assist. dr. Alenka Šalej Lah University of Ljubljana tatjana.rijavec@ntf.uni-lj.si and Engineering Department of Textiles, +386 1 200 32 24 Faculty of Natural Sciences Graphic Arts and Design Snežniška 5 1000, Ljubljana, Slovenia +386 1 200 32 89 alenka.salejlah@ntf.uni-lj.si 41 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION DEGUMMING OF SILK PRODUCED IN SLOVENIA Petra Forte Tavčer1, Maša Šturm1 and Tatjana Rijavec1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Silk degumming is the process of removing sericin, a gummy protein, from silk fibres. This is typically achieved through hydrolytic or enzymatic methods, breaking down sericin’s peptide bonds. The goal is to pro-duce silk that is softer, shinier, and more lustrous. Raw silk, obtained from various Slovenian silk growers, was treated in aqueous solutions with the addition of various chemicals, soap, sodium carbonate, citric acid, and urea under different conditions. Both fibres unwound from cocoons and whole cocoons were treated. Experiments were also conducted on lower quality, damaged, or incompletely developed cocoons. The rate of the degumming was assessed by weighing the fibres before and after treatment and observing them under an electron microscope. Keywords: silk, yarn, cocoon, degumming 1. INTRODUCTION Silk, a natural biopolymer synthesised primarily by silkworms and certain other species, has excellent mechanical strength, aesthetic properties and biocompatibility (Altman, 2003). These properties make it very versatile and enable applications in the textile industry and biomedicine (Aramwit, 2010). Silk fibres produced by the silkworm Bombyx mori L. consist mainly of two proteins, fibroin and sericin. Fibroin is the structural protein that forms the core of silk fibres. Fibroin consists of repeating amino acid sequences, mainly glycine (45%), alanine (30%) and serine (12%), which allow tight packing into β-sheet structures that provide strength and elasticity (Altman et al., 2003). Sericin is a water-soluble protein that coats the fibroin core and acts as a natural adhesive. It is rich in amino acids such as serine, aspartic acid and threonine, which give it hygroscopic and protective properties (Aramwit, 2010). In recent years, silk fibroin has attracted much attention in various fields such as biomedicine, tissue engineering, food processing, photochemistry and biosensing due to its remarkable biocompatibility, machinability and chemical modifiability (Huang, 2023). Sericin has also become a research focus among new natural biomedical materials due to its good moisture absorption, membrane-forming property, antioxidant capacity, antibacterial capacity, tyrosinase inhibition, cell adhesion and proliferation activity, low immunogenicity, hypoglycemic effect and other properties. (Zhi-Lin Zhao, 2020) The removal of sericin from the surface of silk fibres is called degumming. This can be achieved by physical, chemical or enzymatic methods. Alkaline solutions (e.g. sodium carbonate) or soaps are commonly used to dis-solve sericin. Although effective, excessive concentrations of chemicals can damage fibroin (Kweon, 2001). Spe-cific enzymes such as proteases selectively degrade the sericin without damaging the fibroin. This method is more environmentally friendly and preserves the mechanical properties of the silk (Aramwit, 2010). Techniques such as ultrasound, microwave-assisted steam degumming (Pan et al., 2024) or high-pressure processes remove the sericin mechanically (Altman, 2003). Degumming considerably improves the texture, lustre and quality of the silk. Degummed silk is used extensively for luxury textiles and medical applications, including sutures, scaffolds and drug delivery systems. The efficien-cy of degumming has a direct impact on the biocompatibility and functionality of silk, especially in biomedical applications (Aramwit, 2010). The choice of degumming method can have a significant impact on the molecular weight, structure, morphology and properties of silk fibroin and is therefore crucial for both textile and non-textile 42 29–30 May 2025, Ljubljana, Slovenia applications (Vyas, 2015, Zhu, 2022). As part of a bilateral project (Berčič, 2021), several farmers from Slovenia started rearing silkworms and harvesting silk cocoons in 2015‒2021. They produced a considerable amount of high-quality silk cocoons, but some imperfect, damaged cocoons also occurred. The aim of our work was to in 29–30 May 2025, Ljubljana, Slovenia -vestigate how to extract fibroin from these imperfect cocoons. Various chemicals were used for degumming: soap, sodium carbonate, citric acid and urea under different working conditions. 2. METHODS farmers from Slovenia started rearing silkworms and harvesting silk cocoons in 2015‒2021. They produced a aim of our work was to investigate how to extract fibroin from these imperfect cocoons. Various chemicals The silk cocoons were produced in Slovenia in 2024, selected, dried for 24 hours at 60 °C and reeled up. The were used for degumming: soap, sodium carbonate, citric acid and urea under different working conditions. remains after reeling the cocoons were used for analysis. considerable amount of high 2.1 Materials and methods-quality silk cocoons, but some imperfect, damaged cocoons also occurred. The 2. METHODS The cocoons were opened manually with scissors and the pupa was removed. Before degumming, the cocoons 2.1 Materials and methods were yellowish in colour. Four to five cocoons with a total mass of about 1 g were processed together in the same The silk cocoons were produced in Slovenia in 2024, selected, dried for 24 hours at 60 °C and reeled up. The degumming bath. Figure 1 shows the silk covers of the cocoons after removal of the pupae. The cocoons were opened manually with scissors and the pupa was removed. Before degumming, the acetic acid were purchased from Sigma Aldrich. cocoons were yellowish in colour. Four to five cocoons with a total mass of about 1 g were processed together remains after reeling the cocoons were used for analysis. Four different degumming baths were prepared. The recipes are listed in Table 1. Sodium carbonate, urea and in the same degumming bath. Figure 1 shows the silk covers of the cocoons after removal of the pupae. Four different degumming baths were prepared. The recipes are listed in Table 1. Sodium carbonate, urea and acetic acid were purchased from Sigma Aldrich. Table 1: Recipes of the degumming baths Table 1: Recipes of the degumming baths No. Additive Concentration 1. No. Additive Concentration demineralized water 100% 1. 2. demineralized water 100% sodium carbonate 3 g/l 2. sodium carbonate 3 g/l 3. citric acid 1,5% 3. citric acid 1,5% 4. urea 60 g/l 4. urea 60 g/l The treatment was carried out in the Starlet-2 dyeing apparatus (DaeLim, Korea) at 98 °C and a liquor/fibre ratio ratio of 1:100 for 30, 60 and 90 minutes. After treatment, the silk fibres were removed from the degumming rinsed thoroughly with tap water. The fibres were then dried in the air. baths and rinsed thoroughly with tap water. The fibres were then dried in the air. The treatment was carried out in the Starlet-2 dyeing apparatus (DaeLim, Korea) at 98 °C and a liquor/fibre of 1:100 for 30, 60 and 90 minutes. After treatment, the silk fibres were removed from the degumming baths and a) b) c) Figure 1 Figure 1: Silk shells before (a), during (b) and after (c) treatment : Silk shells before (a), during (b) and after (c) treatment 2.2 Analyses 2.2 Analyses The amount of sericin removed was determined by weighing the silk shells before and after treatment and lating the remaining ratio of fibres to removed material as a percentage. Photomicrographs of untreated and all The amount of sericin removed was determined by weighing the silk shells before and after treatment and calcu- calculating the remaining ratio of fibres to removed material as a percentage. Photomicrographs of untreated treated samples were taken using a scanning electron microscope (Jeol 5610, Japan). and all treated samples were taken using a scanning electron microscope (Jeol 5610, Japan). 3. RESULTS AND DISCUSSION Figure 2 shows the proportion of sericin removed from the silk cocoons. It can be seen that the proportion of sericin removed is high in all treatments, ranging from 15 % to 23 %. The highest removal occurred in the treatment with sodium carbonate and citric acid, while less sericin was removed in the treatment with water 43 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS AND DISCUSSION Figure 2 shows the proportion of sericin removed from the silk cocoons. It can be seen that the proportion of sericin removed is high in all treatments, ranging from 15 % to 23 %. The highest removal occurred in the treatment with sodium carbonate and citric acid, while less sericin was removed in the treatment with and urea. No clear time dependence was observed, suggesting that a shorter treatment duration of 30 to 60 water and urea. No clear time dependence was observed, suggesting that a shorter treatment duration of minutes was sufficient to remove most of the sericin. 30 to 60 minutes was sufficient to remove most of the sericin. 25 ) % s ( 20 bre fi m 15 ro ed f 10 ov m e re 5 nc ta bs 0 su 30 60 90 30 60 90 30 60 90 30 60 90 water sodium carbonate citric acid urea time (min)/ degumming bath Figure 2 Figure 2: The proportion of removed substance (sericin) from silk fibres during degumming. : The proportion of removed substance (sericin) from silk fibres during degumming. magnification, degummed silk fibres and fine fibrils can be seen in all treated samples, although the fibrils are shown for each sample: one at lower magnification (230x) and another at higher magnification (1600x). At lower magnification, degummed silk fibres and fine fibrils can be seen in all treated samples, although the more pronounced in the acetic acid treated samples. At higher magnification, some longitudinal damage to the fibrils are more pronounced in the acetic acid treated samples. At higher magnification, some longitudinal shown for each sample: one at lower magnification (230x) and another at higher magnification (1600x). At lower Figure 3 shows silk fibres before and after 90 minutes of degumming with different solutions. Two images are Figure 3 shows silk fibres before and after 90 minutes of degumming with different solutions. Two images are fibres is also visible, indicating that all treatments have caused some fibre damage. This damage may be due to damage to the fibres is also visible, indicating that all treatments have caused some fibre damage. This the high temperatures, long processing times and intense agitation during treatment. In order to obtain high-qual-damage may be due to the high temperatures, long processing times and intense agitation during treatment. ity silk threads, the degumming process must be optimised. In order to obtain high-quality silk threads, the degumming process must be optimised. 44 3 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia SEM photo of silk fibres at 230x SEM photo of silk fibres at 1600x magnification magnification untreated water soda citric acid urea Figure 3 Figure 3: Microphotographs of silk fibres before and after 90 minutes of degumming with different solutions : Microphotographs of silk fibres before and after 90 minutes of degumming with different solutions at 230x at 230x and 1600 x magnification. and 1600x magnification. 4 45 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSION We can conclude that damaged cocoons can be degummed using the same methods as raw silk threads. The sericin is effectively removed, resulting in fibres that can be spun into pure silk threads or used in blends with other textile fibres. The sericin removed from the fibres, which remains in the degumming bath, could also be recycled. During processing, the fibres are damaged, so the processes need to be adapted accordingly. Further research will determine the properties of the cleaned fibres and their potential applications. 5. ACKNOWLEDGEMENT We would like to thank Assoc. Prof. Dr. Rebeka Lucijana Berčič from the Inštitut za svilogojstvo in svilarstvo Re-beka Lucijana Berčič, zasebni zavod za raziskave from Maribor. 6. REFERENCES Altman, G. H., Diaz, F., Jakuba, C., et al. 2003. “Silk-based biomaterials.” Biomaterials 24(3): 401-416. Aramwit, P., Kanokpanont, S., Nakpheng, T., et al. 2010. “The effect of sericin removal on the properties of regenerated silk fibroin films.” International Journal of Molecular Sciences 11(12): 4650-4661. Berčič, R. L. 2021. »Influence of feeding silkmoth (Bombyx mori L.) hybrid larvae with leaves of old local Hungarian and Slovenian mulberry (Morus alba L.) genotypes on the development and health status of larvae«: project code : OTKA SNN 116993 : report. Budapest: University of Veterinary Medicine Budapest. Kweon, H. Y., Ha, H. C., Um, I. C., et al. 2001. “Physical properties of silk fibroin/chitosan blend films.” Journal of Applied Polymer Science 80(7): 928-934. Pan, M., Jin, Y., Ye, Y., Jiang, W., Zhu, L., & Lu, W. 2024. »An efficient and eco-friendly method for removing sericin using microwave-assisted steam degumming.« Environmental Technology & Innovation 35: 103674. Vyas, S., Shukla, S. R. 2015. “Comparative study of degumming of silk varieties by different techniques.” The Journal of The Textile Institute 107: 191 - 199. Zhu, L., Lin, J., Pei, L. et all. 2015 “Recent Advances in Environmentally Friendly and Green Degumming Processes of Silk for Textile and Non-Textile Applications.” Polymers 14(4): 659. Rastogi, S., Kandasubramanian, B. 2020. “Processing trends of silk fibres: Silk degumming, regeneration and physical functionalization.” The Journal of The Textile Institute 111(12): 1794-1810. Zhao, Z.L., Zhang, Y.Q. 2020. “Greener degumming production of layered sericin peptides from a silkworm cocoon and their physicochemical characteristics and bioactivities in vitro.” Journal of Cleaner Production 261: 121080 Huang, L.L., Shi, J.F., Zhou, W., Zhang Q. 2023. “Advances in Preparation and Properties of Regenerated Silk Fibroin.” International Journal of Molecular Sciences 24(17): 13153. Allardyce, B. J. et all., 2015. “The impact of degumming conditions on the properties of silk films for biomedical applications.” Textile Research Journal 86(3): 275-287. ADDITIONAL DATA ABOUT AUTHOR Corresponding author: Co-authors: Petra Forte Tavčer Tatjana Rijavec Faculty of Natual Sciences Faculty of Natual Sciences and Engineering University of Ljubljana University of Ljubljana and Engineering Aškerčeva 12 Aškerčeva 12 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia tatjana.rijavec@ntf.uni-lj.si petra.forte@ntf.uni-lj.si Maša Šturm University of Ljubljana Faculty of Natual Sciences and Engineering Aškerčeva 12 1000 Ljubljana, Slovenia 46 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION DIMENSIONAL STABILITY OF SILK BLEND KNITTED FABRICS Sabina Gabrovšek1 and Živa Zupin1 1University of Ljubljana, Faculty of Natural Science and Technology, Slovenia Abstract: During knitting, the threads are under tension, which deforms the fabric. As soon as the fabric is remo-ved from the machine, it relaxes and its dimensions change. The aim of the research is to investigate the dimen-sional stability of knitted fabrics made from tussah silk blends, which can be used in various applications such as clothing, sportswear and more. Tussah silk is the most important wild silk used commercially. 16 different knitted fabrics were designed and produced from yarns consisting of four different silk blends with wool, cotton, lyocell and acrylic fibres and four different single jersey knit structures. The highest change in dimensional stability was achieved with knitted fabrics made from silk-wool blended yarn, the lowest with knitted fabrics made from a blend of cotton, acrylic and silk. The knitting structures have a small influence on the dimensional stability and other measured properties, but there is also a big difference between the dimensional stability of plain jersey and other structures with tuck stitches, which tend to be looser structures. Keywords: knitted fabrics, silk blends, structures of knitted fabrics, dimensional stability, thickness. 1. INTRODUCTION Tussah silk is the most important wild silk. Tussah silk is obtained from several species of silkworms of the genus Antheraea. These worms feed almost exclusively on the oak Quercus serrata. Despite the different species of worms that produce tussah silk, the cocoons are sufficiently uniform and produce a homogeneous material. The properties of the silk are more influenced by the climatic conditions. Tussah silk differs considerably in appearance from Bombyx mori silk. The cocoons of tussah silk have a greener colour and are covered with tufts of red hair, which is why bleaching and chemical treatment is often necessary. Wild silk is also irregular in width and is char-acterised by longitudinal stripes and flattened areas with horizontal stripes. Wild silk is less durable but is valued for its strength and resilience (Cook, 1993). Tussah silk not only has a luxurious and elegant appearance, but also has physical properties such as high strength and good stretchability (Wang, 2023). The dimensional stability of knitted fabrics is an important factor in the knitting industry. There are several factors that affect the dimensional stability as well as the shrinkage and spirality of knitted fabrics. Although factors such as fibre properties, stitch length, machine gauge, yarn twist and knitting tension causes dimensional variations, the most important factor that causes the spirality of a single jersey fabric is the relaxation of torsional stresses in the yarn (Hossain, 2012) During the knitting process, the yarns forming the fabric are constantly under stress. As a result, the fabric is more deformed on the machine than in its natural, relaxed state. When the fabric is removed from the machine, it has time to relax and overcome this tension. This form of relaxation can be easily recognised by the changed dimensions. For the same fabric structure, different yarn types have different effects on relaxation and physical properties (Quaynor, 2000). Dimensional changes occur either as shrinkage or expansion, but the predominant source of dimensional change in knitted fabrics is yarn relaxation. Due to the extensible nature of knitted fabrics, the limits of dimensional change in knitted fabrics are not considered as critical as in woven fabrics. Most dimen-sional changes due to relaxation shrinkage occur during the first wash cycle, with fabrics changing progressively with each subsequent wash cycle until stability is achieved (Van Amber, 2010). Different fibre blends also have different effects on the change in dimensional stability and other properties of knitted fabrics. Blending natural fibres with man-made fibres can offer the advantage of combining the good prop- 47 29–30 May 2025, Ljubljana, Slovenia erties of both fibre components, such as comfort, softness, strength, etc. The blend highlights the good properties of the fibres and minimises the bad ones (Pooja, 2021). The aim of the study is to compare the dimensional stability and the change in horizontal and vertical density of knitted fabrics, the change in thickness of different silk blend knitted fabrics and different structures after washing. 2. EXPERIMENTAL In our reserch, the dimensional stability of knitted fabrics made from silk blends was investigated. For this pur-pose, sixteen knitted fabrics were designed and produced on the Shima Sheiki SES 122 RT knitting machine with a gauge 12 E, using the same settings for all knitted fabrics. Four different silk blend yarns and four different single jersey structures were used. As the linear density of the yarns of the different materials was not the same for all yarns, two, three or four threads were used for one yarn to produce knitted fabrics. The materials used for the research are presented in Table 1 and the structures of the knitted fabrics are presented in Table 2. The knit-ted fabrics were washed five times under the same conditions. The washing was carried out in a Gorenje Wavw active washing machine, in the sports programme at 30°C and 800 revolutions. 18 ml of a commercially available detergent was used for each wash cycle. The washing time was 39 minutes. After each wash cycle, the samples were dried horizontally. For the purpose of the study horizontal and vertical density was measured on the raw samples, after the first wash and after the five washes. The horizontal and vertical densities (Dh and Dv) were determined by counting the loops over a length of 20 mm. Table 1: Presentation of the materials used in the research. Sample Material Material Tt* yarn No. of threads Total Tt* code (tex) in knitted fabric (tex) 1 2 3 SE/WO 70 % tussah silk, 30 % wool 58.8 1 58.8 4 5 6 7 CLY/SE 70 % lyocell 30 % tussah 40 2 80 silk 8 9 10 35 % cotton, 35 % acrylic, 29.4 CO/PAN/SE 30 % tussah silk 3 88.2 11 12 13 14 15 CO/SE 70 % cotton, 30 % tussah 20 4 80 silk 16 *TT – LINEAR DENSITY OF YARNS 48 29–30 May 2025, Ljubljana, Slovenia Table 2: Presentation of the knitted structures used in the research. Name of structure Single jersey (SJ) Single piqué (SP) Single fang (SF) honeycomb (H) Structure 29–30 May 2025, Ljubljana, Slovenia No. of sample 1, 5, 9, 13 2, 6, 10, 14 3, 7, 11, 15 29–30 May 2025, Ljubljana, Slovenia 4, 8, 12, 16 The change in dimensional stability was measured in accordance with the standard EN ISO 5077:2008 (Textiles - Determination of dimensional change in washing and drying). Dimensional stability was measured after each The change in dimensional stability was measured in accordance with the standard EN ISO 5077:2008 wash. Longitudinal and vertical markings were applied to the samples. The length in the longitudinal direction (Textiles - Determination of dimensional change in washing and drying). Dimensional stability was measured was 50 cm and in the vertical direction 35 cm, as the samples were very wide. Three measurements were carried after each wash. Longitudinal and vertical markings were applied to the samples. The length in the longitudinal The change in dimensional stability was measured in accordance with the standard EN ISO 5077:2008 out for each sample. The dimensional stability was calculated according to equation 1, where l direction was 50 cm and in the vertical direction 35 cm, as the samples were very wide. Three measurements (Textiles - Determination of dimensional change in washing and drying). Dimensional stability was measured is the length washed measured after washing and drying and l were carried out for each sample. The dimensional stability was calculated according to equation 1, where after each wash. Longitudinal and vertical markings were applied to the samples. The length in the longitudinal is the length measured before washing: original l direction was 50 cm and in the vertical direction 35 cm, as the samples were very wide. Three measurements washed is the length measured after washing and drying and l original is the length measured before washing: l 𝑙𝑙𝑙𝑙 𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜−𝑙𝑙𝑙𝑙𝑤𝑤𝑤𝑤𝑜𝑜𝑜𝑜𝑤𝑤𝑤𝑤ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 washed is the length measured after washing and drying and l dimensional change (%) = original is the length measured before washing: ∙ 100 (1) 𝑙𝑙𝑙𝑙 𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 were carried out for each sample. The dimensional stability was calculated according to equation 1, where dimensional change (%) = 𝑙𝑙𝑙𝑙 𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜−𝑙𝑙𝑙𝑙𝑤𝑤𝑤𝑤𝑜𝑜𝑜𝑜𝑤𝑤𝑤𝑤ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 ∙ 100 (1) The area dimensional stability was also calculated using equation 2: 𝑙𝑙𝑙𝑙 𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 The area dimensional stability was also calculated using equation 2: The area dimensional stability was also calculated using equation 2: ( 𝑙𝑙𝑙𝑙 𝐻𝐻𝐻𝐻𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 ∙𝑙𝑙𝑙𝑙 𝑉𝑉𝑉𝑉𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 ) −𝑙𝑙𝑙𝑙 𝐻𝐻𝐻𝐻𝑤𝑤𝑤𝑤𝑜𝑜𝑜𝑜𝑤𝑤𝑤𝑤ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒∙𝑙𝑙𝑙𝑙𝑉𝑉𝑉𝑉𝑤𝑤𝑤𝑤𝑜𝑜𝑜𝑜𝑤𝑤𝑤𝑤ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒) area dimensional change (%) = ∙ 100 2 𝑙𝑙𝑙𝑙 𝐻𝐻𝐻𝐻𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 ∙𝑙𝑙𝑙𝑙𝑉𝑉𝑉𝑉𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 The thickness of the knitted fabric was measured on the raw samples, after the first and after five washes with 𝑙𝑙𝑙𝑙 𝐻𝐻𝐻𝐻𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 ∙𝑙𝑙𝑙𝑙 𝑉𝑉𝑉𝑉𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 2 area dimensional change (%) = (𝑙𝑙𝑙𝑙𝐻𝐻𝐻𝐻𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜∙𝑙𝑙𝑙𝑙𝑉𝑉𝑉𝑉𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜)−𝑙𝑙𝑙𝑙𝐻𝐻𝐻𝐻𝑤𝑤𝑤𝑤𝑜𝑜𝑜𝑜𝑤𝑤𝑤𝑤ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒∙𝑙𝑙𝑙𝑙𝑉𝑉𝑉𝑉𝑤𝑤𝑤𝑤𝑜𝑜𝑜𝑜𝑤𝑤𝑤𝑤ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒) ∙ 100 2 a pressure of 20 cN/cm . The thickness of the knitted fabric was measured according to the standard SIST EN The thickness of the knitted fabric was measured on the raw samples, after the first and after five washes with a After five washes, the mass per unit area of the knitted fabric was measured in accordance with the standard a pressure of 20 cN/cm 2 . The thickness of the knitted fabric was measured according to the standard SIST EN SIST EN 12127: 1999 (Textiles - Fabrics - Determination of mass per unit area using small samples). ISO 5084:1999 (Textiles - Determination of thickness of textiles and textile products). The thickness of the knitted fabric was measured on the raw samples, after the first and after five washes with pressure of 20 cN/cm ISO 5084:1999 (Textiles - Determination of thickness of textiles and textile products). 2 . The thickness of the knitted fabric was measured according to the standard SIST EN ISO 5084:1999 (Textiles - Determination of thickness of textiles and textile products). After five washes, the mass per unit area of the knitted fabric was measured in accordance with the standard After five washes, the mass per unit area of the knitted fabric was measured in accordance with the standard SIST All knitted fabrics were produced with the same set density (yarn feed tension, cam setting and take-down EN 12127: 1999 (Textiles - Fabrics - Determination of mass per unit area using small samples). 3. RESULTS WITH DISCUSSION SIST EN 12127: 1999 (Textiles - Fabrics - Determination of mass per unit area using small samples). 3. RESULTS WITH DISCUSSION tension), but have different degrees of relaxation after knitting due to differences in the knitted structure and the material used. This influences the different horizontal (Dh) and vertical density (Dv) of the knitted samples. All knitted fabrics were produced with the same set density (yarn feed tension, cam setting and take-down As can be seen in Table 3, the highest horizontal density was found in plain single jersey structures (SJ), while tension), but have different degrees of relaxation after knitting due to differences in the knitted structure and All knitted fabrics were produced with the same set density (yarn feed tension, cam setting and take-down tension), the opposite, the highest density is achieved with honeycomb structures and the lowest with plain simple single As can be seen in Table 3, the highest horizontal density was found in plain single jersey structures (SJ), while jersey structures. These results show that the structure has a major influence on the horizontal and vertical 3. the lowest was achieved with single fang (SF) and honeycomb structures (H). While in vertical density shows the material used. This influences the different horizontal (Dh) and vertical density (Dv) of the knitted samples. RESULTS WITH DISCUSSION but have different degrees of relaxation after knitting due to differences in the knitted structure and the material density of knitted fabrics, much more than the material used. Single jersey (SJ) is the simplest knitted structure the lowest was achieved with single fang (SF) and honeycomb structures (H). While in vertical density shows used. This influences the different horizontal (Dh) and vertical density (Dv) of the knitted samples. As can be seen where all stitches are the same, while the structures with more tuck stitches are more stretchy in width and the opposite, the highest density is achieved with honeycomb structures and the lowest with plain simple single in Table 3, the highest horizontal density was found in plain single jersey structures (SJ), while the lowest was more compressed vertically. density of knitted fabrics, much more than the material used. Single jersey (SJ) is the simplest knitted structure jersey structures. These results show that the structure has a major influence on the horizontal and vertical achieved with single fang (SF) and honeycomb structures (H). While in vertical density shows the opposite, the where all stitches are the same, while the structures with more tuck stitches are more stretchy in width and highest density is achieved with honeycomb structures and the lowest with plain simple single jersey structures. Our research has shown that dimensional stability varies greatly depending on the structure and material used. more compressed vertically. These results show that the structure has a major influence on the horizontal and vertical density of knitted fabrics, All knitted fabric samples produced shrank after washing. As expected, the greatest change in dimensional much more than the material used. Single jersey (SJ) is the simplest knitted structure where all stitches are the stability, both horizontally and vertically, was observed after the first washing and drying of the fabrics. The Our research has shown that dimensional stability varies greatly depending on the structure and material used. same, while the structures with more tuck stitches are more stretchy in width and more compressed vertically. samples shrank by 8 to 20 % in the horizontal direction and by 4 to 16 % in the vertical direction. After further All knitted fabric samples produced shrank after washing. As expected, the greatest change in dimensional Our research has shown that dimensional stability varies greatly depending on the structure and material used. All seen in Figures 1 and 2. samples shrank by 8 to 20 % in the horizontal direction and by 4 to 16 % in the vertical direction. After further knitted fabric samples produced shrank after washing. As expected, the greatest change in dimensional stability, washes, the shrinkage is not as high but depends on the type of structure and the material used, as can be stability, both horizontally and vertically, was observed after the first washing and drying of the fabrics. The both horizontally and vertically, was observed after the first washing and drying of the fabrics. The samples shrank The shrinkage is generally highest in the horizontal direction. This can also be confirmed from the literature seen in Figures 1 and 2. washes, the shrinkage is not as high but depends on the type of structure and the material used, as can be (Quaynor, 1999), which states that silk fabrics actually tend to stretch in the lengthwise direction (negative shrinkage). Figure 3, which shows the area dimensional stability confirms that the highest shrinkage in both The shrinkage is generally highest in the horizontal direction. This can also be confirmed from the literature directions is observed in knitted fabrics made of silk-wool blends, followed by knitted fabrics made of cotton-(Quaynor, 1999), which states that silk fabrics actually tend to stretch in the lengthwise direction (negative silk blends, while knitted fabrics made of lyocell and silk blends as well as cotton, acrylic and silk blends show shrinkage). Figure 3, which shows the area dimensional stability confirms that the highest shrinkage in both the least change in dimensional stability. One of the reasons for the highest shrinkage of silk and wool blends directions is observed in knitted fabrics made of silk-wool blends, followed by knitted fabrics made of cotton-49 is the dimensional instability of the wool. The flake structure of the wool led to a slight flattening of the knitted silk blends, while knitted fabrics made of lyocell and silk blends as well as cotton, acrylic and silk blends show fabric after the four and five washes, which resulted in even greater shrinkage. The structure and properties of the least change in dimensional stability. One of the reasons for the highest shrinkage of silk and wool blends the wool have a major influence on the properties of the knitted fabric in the silk/wool blend, even though the is the dimensional instability of the wool. The flake structure of the wool led to a slight flattening of the knitted 29–30 May 2025, Ljubljana, Slovenia by 8 to 20 % in the horizontal direction and by 4 to 16 % in the vertical direction. After further washes, the shrink-age is not as high but depends on the type of structure and the material used, as can be seen in Figures 1 and 2. The shrinkage is generally highest in the horizontal direction. This can also be confirmed from the literature (Quay-nor, 1999), which states that silk fabrics actually tend to stretch in the lengthwise direction (negative shrinkage). Figure 3, which shows the area dimensional stability confirms that the highest shrinkage in both directions is observed in knitted fabrics made of silk-wool blends, followed by knitted fabrics made of cotton-silk blends, while knitted fabrics made of lyocell and silk blends as well as cotton, acrylic and silk blends show the least change in dimensional stability. One of the reasons for the highest shrinkage of silk and wool blends is the dimensional instability of the wool. The flake structure of the wool led to a slight flattening of the knitted fabric after the four and five washes, which resulted in even greater shrinkage. The structure and properties of the wool have a major influence on the properties of the knitted fabric in the silk/wool blend, even though the proportion of wool in the blend is only 30%. Due to the high proportion of silk, a greater number of washes may also be required to achieve a fully relaxed state (Van Amber, 2010). One of the reasons why shrinkage is highest in silk-wool blends is also the linear density of the yarn. The linear density is the lowest and allows for more shrinkage because the structure is more porous and provides more room for shrinkage. Table 3: Horizontal and vertical density of knitted fabrics before washing and mass per unit area after five washes. Before washing Sample Dh (wales/2cm) C V Dv CV (%) Mass after 5 washes (g/ CV (%) (%) m2) (courses/2cm) 1 12.85 5.20 16.45 2.66 247.47 0.18 2 11.2 2.31 19.5 2.09 290.88 0.29 3 9.15 2.64 22.7 2.79 302.09 0.20 4 8.9 2.37 25.35 5.20 318.33 0.13 5 12.85 1.88 15.8 2.67 299.3 2.35 6 11 4.29 19.45 2.25 334.06 0.95 7 9.2 2.81 22.1 1.43 322.96 0.47 8 9.2 2.81 21.05 1.75 314.44 1.86 9 12.45 2.96 16.55 2.65 343.67 0.13 10 11.75 6.10 20.1 3.48 387.02 0.29 11 9.35 3.61 18.8 3.12 394.89 0.39 12 9.15 2.64 22.95 2.40 351.75 0.37 13 12.65 3.25 16.35 2.52 341.43 0.20 14 11.6 3.40 20.45 2.43 351.99 1.74 15 9,75 3,63 18,15 2,61 355,68 1,49 16 9,45 3,00 22,05 1,29 340,77 0,63 50 11 9.35 3.61 18.8 3.12 394.89 0.39 12 9.15 2.64 22.95 2.40 351.75 0.37 13 12.65 3.25 16.35 2.52 341.43 29–30 May 2025, Ljubljana, Slovenia 0.20 14 11.6 3.40 20.45 2.43 351.99 1.74 15 9,75 3,63 18,15 2,61 355,68 1,49 16 9,45 3,00 22,05 1,29 340,77 0,63 Figure 1: Change in dimensional stability of knitted Figure 2: Change in dimensional stability of knitted fabrics - horizontal before washing and after the 1st fabrics - vertical before washing and after the 1st and and 5 washes 5 washes Figure 3: Ara dimensional stability change of Figure 3: Change in the thickness of knitted fabrics st knitted fabrics after all five washes. before washing and after the 1 and 5 washes. High shrinkage is also achieved with knitted fabrics made from cotton-silk blends. The blend consists of 30% silk and 70% cotton, which can shrink during washing. Figures 1, 2 and 3 show that the knitted fabrics made from a cotton-silk blend shrinks the most in the horizontal and vertical directions after the first wash. After two, three and four washes there is only a slight change in dimensional stability, after five washes an expansion of the knitted fabrics is even observed in knitted structures with touch stiches. The least change in dimensional stability is observed in knitted fabrics made from acrylic and silk blends. One of the reasons for this is the proportion of 30% acrylic fibres, which are non-absorbent and do not tend to shrink after washing. This blend also has the highest linear density of the yarn and thus the most compact structure and therefore the least shrinkage. The knitted structure also has an influence on the dimensional stability of knitted fabrics. In the horizontal direc-tion, the greatest change in dimensional stability was observed in knitted fabrics with more tuck stitches, such as single fang (SF) and honeycomb (H) structures, while single jersey (SJ) fabrics showed the least shrinkage. The reason for this is the tuck stitches in the structure. In the horizontal direction, the tuck stitches shrink the structure of the knitted fabric and thus also influence the dimensional stability after washing. In the vertical direction, shrinkage after washing is highest in single jersey (SJ), while shrinkage is lower in tuck knitted structures. The more tuck stitches, the wider the fabrics; the lowest shrinkage is observed with single fang (SF) and honeycomb (H). Structures with tuck stitches are more stretchable in width, as tuck stitches are looser. The change in the thickness of the knitted fabric was also analysed after the first and after the five washes. The results showed that the thickness increased on average by slightly more than 20% after the first wash, depending on the structure and material of the knitted fabric, while the change in thickness after the five washes was only about 4% more than after the first wash. After the first wash, the thickness of the knitted fabric increased the most in wool-silk blends and cotton-silk blends, which also show the highest shrinkage. After the fifth wash, the 51 29–30 May 2025, Ljubljana, Slovenia thickness of wool and silk blends knitted fabrics increased significantly, while the increase in the other materials was minimal. The structure of the knitted fabric also has a major influence on the change in thickness. In general, knitted structures with tuck stitches have a higher increase in the thickness of the knitted fabrics, as structures with tuck stitches also have a higher shrinkage. In general, structures with tuck stitches are thicker than single jersey structures. The change in dimensional stability also has an effect on the mass per unit area, as can be seen in Table 3. Fab-rics with higher shrinkage also have a higher mass per unit area after five washes. 4. CONCLUSIONS The results of the study show how the different silk blend yarns used for the knitted fabrics and their structure in-fluence the physical properties, such as horizontal and vertical density, dimensional stability and thickness. It also shows how the different silk blends differ from each other and how the dimensional stability changes after each of the five washes. From the results, it can be concluded that the highest change in dimensional stability of the tested knitted fabrics is observed in knitted fabrics made from a blend of silk and wool, followed by knitted fabrics made from cotton and silk, while the lowest change in dimensional stability is observed in knitted fabrics made from cotton, acrylic and a silk blend. The knitted structure also has a major influence on physical properties such as horizontal and vertical density, mass per unit area and dimensional stability. As expected, the knitted fabrics with more tuck stitches shrink more than plain single jersey structures. The more tuck stitches, the looser the structure and the higher the shrinkage. The greatest change in dimensional stability was observed in the honeycomb structure and the single fang struc-ture. 5. REFERENCES Cook, G. 1993. Handbook of Textile Fibres. Shildon : Merrow. Hossain M., et al. 2012. “Impact of Various Yarn of Different Fiber Composition on the Dimensional Properties of Different Structure of Weft Knitted Fabrics.” International Journal of Textile and Fashion Technology (IJTFT) 2(1): 34–44. Jingyu Wang, Xinxi Liu. 2023. “Research on the Characteristics and Development of Liaoning Tussah Silk.” Frontiers in Art Research 5(6): 53–57. Pooja, Bains, S., Singh, P. 2021. “Evaluation of mechanical properties of oak tasar silk waste/viscose blended knitted fabrics.” The Pharma Innovation Journal 10(1): 735–738. Quaynor, L., Takahashi, M., Nakajima, M. 2000. “Effects of Laundering on the Surface Properties and Dimensional Stability of Plain Knitted Fabrics” Textile Research Journal 70(1): 28–35. Quaynor, L., Nakajima, M., Takahashi, M. 1999. “Properties of Silk and Silk-blend Knitted Fabrics”. Textile Research Journal 80(15): 1557–1568. Van Amber, R.R, Niven, B.E., Wilson, C. A. 2010. “Effects of Laundering and Water Temperature on the Properties of Silk and Silk-blend Knitted Fabrics”. Textile Research Journal 80(15): 1557–1568. 52 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHOR Corresponding author: Co-author(s): Živa Zupin Sabina Gabrovšek University of Ljubljana University of Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering, Department of Textiles, Department of Textiles, Chair of Textile Aškerčeva 12 1000 Ljubljana, Slovenia Graphic Arts and Design Graphic Arts and Design and Clothing Engineering sg6016@student.uni-lj.si Aškerčeva 12 1000 Ljubljana, Slovenia +386 1 200 23 00 ziva.zupin@ntf.uni-lj.si 53 SUSTAINABLE AND ECO-FRIENDLY TEXTILE MATERIALS 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION NATURAL PROTECTION OF BACTERIAL CELLULOSE DURING INCUBATION Linda Ogrizek1, Janja Lamovšek2, Franci Čuš2 and Marija Gorjanc3 1BION INSTITUTE Ltd., Slovenia 2Agricultural Institute of Slovenia, Slovenia 3University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Bacterial cellulose (BC) is a natural polymer with potential textile applications, but its industrial produc-tion faces challenges due to the fungal contamination during incubation. This study investigates natural bioactive compounds from avocado seeds and white grape bagasse (WGB) as sustainable BC culture media additives. BC was cultivated in three media: Hestrin-Schramm (HS), HS with ground avocado seeds (HS+AS), and WGB me-dium. WGB medium yielded the highest BC production (2.38 ± 0.12 g/L), significantly outperforming HS medium, while HS+AS inhibited BC production (0.20 ± 0.03 g/L). WGB medium exhibited high polyphenol content (476.8 ± 2.5 mg/L) and antioxidant activity (88.4 ± 0.2%), attributed to compounds like catechin and quercetin-3-gluco-side, which effectively inhibited fungal contamination. Morphological analysis showed compact fibrillar structures with fewer pores in WGB-produced BC. These findings highlight WGB’s polyphenol-rich profile as a sustainable solution for fungal contamination and enhanced BC production, offering a promising approach for eco-friendly industrial applications. Keywords: bacterial cellulose, natural protection, polyphenols, antioxidant activity. 1. INTRODUCTION Cellulose is the most widespread, renewable and commonly used natural polymer, mainly derived from plants, but can also be synthesized by bacteria, which represent an increasingly important sustainable source of cellulose (Seddiqi 2021). Bacterial cellulose (BC) has been investigated as an alternative material in several areas, includ-ing the textile industry (Ogrizek 2021; Ogrizek 2024). The potential use of BC in future textile applications ranges from simple clothing and accessories to wearable electronics (Nayak 2024). During the cultivation (incubation) of bacterial cellulose, especially when culturing under non-sterile conditions, e.g. in industry, fungal contamination can sometimes be detected, which is an undesirable infection and can significantly affect the quality of BC. As an option to limit contamination, the addition of sodium benzoate and potassium sorbate or lowering the acidity of the medium below pH 4 by adding citric acid and disodium hydrogen phosphate is recommended (Laavanya 2021; Quijano 2017; Revin 2018). However, plant extracts are widely recognized for their bioactive compounds, particularly phenolic groups, which exhibit antimicrobial properties against food pathogens and spoilage micro-organisms (Gonelimali 2018; Kaur 2021). Key antifungal constituents include phenolic compounds like gallic acid, flavonoids (e.g., catechin), and tannins, which disrupt microbial membranes and enzymatic pathways (Hsu 2021; Efenberger-Szmechtyk 2021). Natural antimicrobial agents can be derived from cultivated plants, such as thyme and rosemary, or from by-products like avocado seeds (Rojas-García 2022). Avocado seeds, a significant by-product of the avocado processing industry, account for approximately 16‒20% of the fruit’s mass and are rich in carbohydrates, polyphenols (e.g., catechins, flavonoids), and tannins, which exhibit strong antimicrobial and antioxidant properties (Pedreschi 2019; Zaki 2020). Their bioactivity varies with extraction methods, with water-based extractions demonstrating high antioxidant and antimicrobial efficacy (Nwaoguikpe 2011; Ong 2022). Grape bagasse, a by-product of winemaking, is a rich source of polyphenols, including phenolic acids (gallic and ellagic), flavonoids (catechin and epicatechin), proanthocyanidins, and stilbenes (Jug 2016; Troilo 2021). Poly-phenols in grape bagasse play a crucial role in protecting plants against pathogens, making them promising can-didates for antifungal and antibacterial applications. Approximately 60‒70% of total polyphenols are concentrated in the seeds, which are particularly rich in antioxidant compounds such as vitamin E, flavonoids, and stilbenes. 55 29–30 May 2025, Ljubljana, Slovenia The skin and pulp also contribute significant amounts of polyphenols, including flavonols (quercetin, kaempferol) 29–30 May 2025, Ljubljana, Slovenia and fibres (Jug 2016; Troilo 2021). 2. EXPERIMENTAL 2.1 BC PRODUCTION AND HARVEST flavonoids, and stilbenes. The skin and pulp also contribute significant amounts of polyphenols, including flavonols (quercetin, kaempferol) and fibres (Jug 2016; Troilo 2021). Bacterial cellulose was grown in different culture media as described in Table 1 below in Hestrin-Schramm (HS) medium, a modified HS medium with added ground avocado seed (HS+A) and white grape bagasse medium EXPERIMENTAL (WGB) using the procedure as described here (Ogrizek 2021). 1. BC PRODUCTION AND HARVEST Bacterial cellulose was grown in different culture media as described in Table 1 below in Hestrin-Schramm Table 1: (HS) medium, a modified HS medium with added ground avocado seed (HS+A) and white grape bagasse Procedures for BC preparation and labelling of samples were carried out according to the established protocol. medium (WGB) using the procedure as described here (Ogrizek 2021). Table 1: Procedures for BC preparation and labelling of samples were carried out according to the Medium Composition of medium Sample label established protocol. 20 g/L glucose Medium 5 g/L yeast extract Composition of medium Sample label Hestrin-Schramm 5 g/L peptone HS 4.5 g/L Na 20 g/L glucose distilled water to 1 L 5 g/L yeast extract HPO 2 4 Hestrin-Schramm 5 g/L peptone HS 20 g/L glucose 4.5 g/L Na 2 HPO4 Modified HS medium with added ground avocado 5 g/L yeast extract distilled water to 1 L seed 5 g/L peptone 20 g/L glucose HS+AS Modified HS medium with added ground avocado 4.5 g/L Na 5 g/L yeast extract HPO 2 4 White grape bagasse white grape bagasse extract 4.5 g/L Na 2 HPO 4 WGB 10 g/L ground avocado seed seed 10 g/L ground avocado seed 5 g/L peptone HS+AS White grape bagasse white grape bagasse extract only only WGB 3. ANALYSIS 2. ANALYSIS BC production was recorded as the dry weight of BC within the volume of medium, according to Equation (1) BC production was recorded as the dry weight of BC within the volume of medium, according to Equation (1) (Vazquez 2013): (Vazquez 2013): 𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵 𝑚𝑚𝑚𝑚 𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝 = (1) 𝑉𝑉𝑉𝑉 where m is the dry weight of BC (g), and V is the volume (L) of the medium for BC production. where m is the dry weight of BC (g), and V is the volume (L) of the medium for BC production. The morphological characteristics of BC were examined using a scanning electron microscope (SEM) (JSM-The morphological characteristics of BC were examined using a scanning electron microscope (SEM) (JSM-6060LV, JEOL, Japan). Total polyphenols in the WGB medium were analysed according to procedure 6060LV, JEOL, Japan). Total polyphenols in the WGB medium were analysed according to procedure described described in Di Stefano and Guidoni (1989) and Rigo et al. (2000). The antioxidant activity (AA) in HS and in Di Stefano and Guidoni (1989) and Rigo et al. (2000). The antioxidant activity (AA) in HS and WGB media was WGB media was analysed according to procedure described in Šmid et al. 2023. analysed according to procedure described in Šmid et al. 2023. RESULTS WITH DISCUSSION 4. We hypothesized that natural antimicrobial compounds from plant food waste could prevent mould RESULTS WITH DISCUSSION contamination without inhibiting K. xylinus growth. Based on its selective activity, avocado seed powder was identified as a candidate. Previous observations suggested that white grape bagasse (WGB) medium prevents We hypothesized that natural antimicrobial compounds from plant food waste could prevent mould contamination contamination. To confirm these findings, BC production was monitored in HS, WGB, and HS supplemented without inhibiting K. xylinus growth. Based on its selective activity, avocado seed powder was identified as a can-with 10 g/L avocado seed powder (HS+AS) over three weeks (Figure 1). didate. Previous observations suggested that white grape bagasse (WGB) medium prevents contamination. To confirm these findings, BC production was monitored in HS, WGB, and HS supplemented with 10 g/L avocado seed powder (HS+AS) over three weeks (Figure 1). 56 2 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia a) a) b) b) c) Figure Figure 1: Media (i) HS, (ii) WGB, and (iii) HS+AS for BC production: a) after one week, b) after two weeks, c) after three 1: Media (i) HS, (ii) WGB, and (iii) HS+AS for BC production: a) after one week, b) after two weeks, weeks of incubation. c) c) after three weeks of incubation. turbidity may be attributed to the starch content of the avocado seed (Tesfaye 2018, Esquivel-Fajardo 2022, was noticed in the medium containing the avocado seed (Figure 1a (iii) and 1b (iii)). This turbidity may be attribut-After one and two weeks of incubation, no visible changes were observed in the culture media. ed to the starch content of the avocado seed (Tesfaye 2018, Esquivel-Fajardo 2022, Lubis 2018). When starch Lubis 2018). When starch granules dissolve or become suspended in water, they can alter the optical However, turbidity was noticed in the medium containing the avocado seed (Figure 1a (iii) and 1b (iii)). This granules dissolve or become suspended in water, they can alter the optical properties of the solution, including properties of the solution, including increased turbidity (Tesfaye 2018, Humaj 2023). After a three-week turbidity may be attributed to the starch content of the avocado seed (Tesfaye 2018, Esquivel-Fajardo 2022, increased turbidity (Tesfaye 2018, Humaj 2023). After a three-week incubation period, fungal contamination was incubation period, fungal contamination was detected only in the HS medium (Figure 1c (i)). Lubis 2018). When starch granules dissolve or become suspended in water, they can alter the optical detected only in the HS medium (Figure 1c (i)). After one and two weeks of incubation, no visible changes were observed in the culture media. c) after three weeks of incubation. After one and two weeks of incubation, no visible changes were observed in the culture media. However, turbidity However, turbidity was noticed in the medium containing the avocado seed (Figure 1a (iii) and 1b (iii)). This Figure 1: Media (i) HS, (ii) WGB, and (iii) HS+AS for BC production: a) after one week, b) after two weeks, exhibited a more compact structure, characterized by densely arranged and interwoven fibrils. Consequently, was also investigated. Regardless of the medium used for BC production, all BC membranes formed a 3D struc The influence of the avocado seed on the morphology of BC membranes (Figure 2) and BC production (Figure -3) was also investigated. Regardless of the medium used for BC production, all BC membranes formed a 3D ture with interwoven cellulose fibrils (Figure 2). BC membranes cultivated in WGB and HS+AS media exhibited a their surfaces displayed fewer visible pores, or none, compared to the BC membrane produced in the HS structure with interwoven cellulose fibrils (Figure 2). BC membranes cultivated in WGB and HS+AS media more compact structure, characterized by densely arranged and interwoven fibrils. Consequently, their surfaces medium (Figure 2a). 3) was also investigated. Regardless of the medium used for BC production, all BC membranes formed a 3D incubation period, fungal contamination was detected only in the HS medium (Figure 1c (i)). The influence of the avocado seed on the morphology of BC membranes (Figure 2) and BC production (Figure 3) structure with interwoven cellulose fibrils (Figure 2). BC membranes cultivated in WGB and HS+AS media The influence of the avocado seed on the morphology of BC membranes (Figure 2) and BC production (Figure properties of the solution, including increased turbidity (Tesfaye 2018, Humaj 2023). After a three-week In the WGB sample (Figure 2b), the presence of displayed fewer visible pores, or none, compared to the BC membrane produced in the HS medium (Figure 2a). exhibited a more compact structure, characterized by densely arranged and interwoven fibrils. Consequently, prepared simultaneously. K. xylinus bacteria remain active (and viable) as long as a sufficient nutrient supply K. xylinus bacteria on the surface was observed, likely due the intentional termination of the BC cultivation process, as all membranes were prepared simultaneously. K. xy-is available. The WGB medium still contained adequate nutrients when the cultivation process was halted, and to the intentional termination of the BC cultivation process, as all membranes were linus bacteria remain active (and viable) as long as a sufficient nutrient supply is available. The WGB medium still the subsequent NaOH post-treatment did not fully remove the bacteria. prepared simultaneously. K. xylinus bacteria remain active (and viable) as long as a sufficient nutrient supply contained adequate nutrients when the cultivation process was halted, and the subsequent NaOH post-treatment is available. The WGB medium still contained adequate nutrients when the cultivation process was halted, and to the intentional termination of the BC cultivation process, as all membranes were medium (Figure 2a). In the WGB sample (Figure 2b), the presence of K. xylinus bacteria on the surface was observed, likely due to In the WGB sample (Figure 2b), the presence of their surfaces displayed fewer visible pores, or none, compared to the BC membrane produced in the HS K. xylinus bacteria on the surface was observed, likely due did not fully remove the bacteria. the subsequent NaOH post-treatment did not fully remove the bacteria. a) b) c) a) b) c) Figure 2: SEM images of BC membranes produced in a) HS, b) WGB in c) HS+AS media. Figure 2: SEM images of BC membranes produced in a) HS, b) WGB in c) HS+AS media. The results of BC membrane production are presented in Figure 3. After three weeks of cultivation, the BC Figure 2: SEM images of BC membranes produced in a) HS, b) WGB in c) HS+AS media. yield was highest in the WGB medium, reaching 2.38 ± 0.12 g/L, 3.5 times greater than the BC production The results of BC membrane production are presented in Figure 3. After three weeks of cultivation, the BC yield was highest in the WGB medium, reaching 2.38 ± 0.12 g/L, 3.5 times greater than the BC production 3 3 57 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia The results of BC membrane production are presented in Figure 3. After three weeks of cultivation, the BC yield was highest in the WGB medium, reaching 2.38 ± 0.12 g/L, 3.5 times greater than the BC production obtained from the conventional HS medium (0.67 ± 0.13 g/L). In the HS+AS medium, a significant reduction in BC produc-obtained from the conventional HS medium (0.67 ± 0.13 g/L). In the HS+AS medium, a significant reduction in tion was observed, with a production of only 0.20 ± 0.03 g/L (Figure 3). This indicates that the avocado seed exerts BC production was observed, with a production of only 0.20 ± 0.03 g/L (Figure 3). This indicates that the an inhibitory effect not only on fungal growth but also on BC production. From this perspective, using avocado avocado seed exerts an inhibitory effect not only on fungal growth but also on BC production. From this seed for BC production is not advisable. Subsequently, the total polyphenol content (TPC) and antioxidant activity of the WGB medium were Subsequently, the total polyphenol content (TPC) and antioxidant activity of the WGB medium were determined, perspective, using avocado seed for BC production is not advisable. determined, along with the comparison of these parameters in HS and WGB media (Table 2). along with the comparison of these parameters in HS and WGB media (Table 2). Figure 3: Production (g/L) of BC in HS, WGB and HS+AS media. Figure 3: Production (g/L) of BC in HS, WGB and HS+AS media. Table 2 shows that the WGB culture medium has a high antioxidant activity, while the HS medium does not. which act as natural antimicrobial agent and inhibit the growth and development of pathogenic microorganisms, Table 2 shows that the WGB culture medium has a high antioxidant activity, while the HS medium does not. The The high antioxidant activity of the WGB medium is related to a high content of polyphenols (476.8 ± 2.5 mg/l), including moulds. high antioxidant activity of the WGB medium is related to a high content of polyphenols (476.8 ± 2.5 mg/l), which act as natural antimicrobial agent and inhibit the growth and development of pathogenic microorganisms, includ- Table 2: ing moulds. Total polyphenols (TPC) in WGB medium and antioxidant activity (AA) in HS and WGB media. Medium TPC (mg/l) AA (%) Table 2: HS ‒* 22.5 ± 0.3 Total polyphenols (TPC) in WGB medium and antioxidant activity (AA) in HS and WGB media. WGB 476.8 ± 2.5 88.4 ± 0.2 Polyphenols act as natural antimicrobial agents, inhibiting the growth and development of pathogenic HS ‒* 22.5 ± 0.3 microorganisms, including moulds (Jug 2016, Humaj 2023, Czaplicka 2022). Humaj et al. (Humaj 2023) * The value was not determined. Medium TPC (mg/l) AA (%) analyzed polyphenols in the leaves, stems, skins, and seeds of the grapevine cultivar Souvignier gris (the WGB 476.8 ± 2.5 88.4 ± 0.2 same variety used in our study) and identified a total of 33 polyphenols. The dominant compound varied for * The value was not determined. each plant part. The primary polyphenols in the skin were quercetin-3-glucoside, caftaric acid, and coutaric acid; in the seeds, catechin, epicatechin, procyanidin B2, C, and B1, and gallic acid predominated; and in the Polyphenols act as natural antimicrobial agents, inhibiting the growth and development of pathogenic microorgan-stems, catechin, procyanidin B1, caftaric acid, coutaric acid, trans-resveratrol, and quercetin-3-glucoside were isms, including moulds (Jug 2016, Humaj 2023, Czaplicka 2022). Humaj et al. (Humaj 2023) analyzed polyphe-most prevalent. Czaplicka et al. (Czaplicka 2022) also demonstrated that the Souvignier gris variety exhibits nols in the leaves, stems, skins, and seeds of the grapevine cultivar Souvignier gris (the same variety used in our significant antioxidant properties due to its high polyphenol content. study) and identified a total of 33 polyphenols. The dominant compound varied for each plant part. The primary CONCLUSIONS polyphenols in the skin were quercetin-3-glucoside, caftaric acid, and coutaric acid; in the seeds, catechin, epi-catechin, procyanidin B2, C, and B1, and gallic acid predominated; and in the stems, catechin, procyanidin B1, WGB contains various polyphenols, such as quercetin-3-glucoside, catechin, and epicatechin, which exhibit caftaric acid, coutaric acid, trans-resveratrol, and quercetin-3-glucoside were most prevalent. Czaplicka et al. antimicrobial properties by inhibiting the growth of microorganisms, including moulds. The presence of these (Czaplicka 2022) also demonstrated that the Souvignier gris variety exhibits significant antioxidant properties due natural compounds not only offers a promising approach to reducing microbial contamination but also aligns to its high polyphenol content. with the principles of sustainable and eco-friendly production practices. Utilizing such bioactive compounds in industrial BC production can provide a dual benefit: minimizing the need for synthetic preservatives or strict sterile conditions, while simultaneously enhancing the overall yield and quality of BC. These findings highlight 5. CONCLUSIONS the potential of integrating natural, polyphenol-rich resources into biotechnological processes, paving the way for cost-effective and environmentally responsible production strategies. WGB contains various polyphenols, such as quercetin-3-glucoside, catechin, and epicatechin, which exhibit anti-microbial properties by inhibiting the growth of microorganisms, including moulds. The presence of these natural compounds not only offers a promising approach to reducing microbial contamination but also aligns with the principles of sustainable and eco-friendly production practices. Utilizing such bioactive compounds in industrial BC production can provide a dual benefit: minimizing the need for synthetic preservatives or strict sterile condi- 4 58 29–30 May 2025, Ljubljana, Slovenia tions, while simultaneously enhancing the overall yield and quality of BC. These findings highlight the potential of integrating natural, polyphenol-rich resources into biotechnological processes, paving the way for cost-effective and environmentally responsible production strategies. 6. 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In Muhamad, I.I. 2015. ”Monitoring the effect of pH on bacterial cellulose production and Acetobacter xylinum 0416 growth in a rotary discs reactor.” Arabian Journal for Science and Engineering, 40: 1881–1885. Zaki, S.A., Ismail, F.A.-A., Abdelatif, S.H., El-Mohsen, N.R. In Helmy, S.A. 2020. ”Research article bioactive compounds and antioxidant activities of avocado peels and seeds.” Pakistan Journal of Biological Sciences, 2020, 23: 345–350. ADDITIONAL DATA ABOUT AUTHOR Corresponding author: Co-author(s): Linda Ogrizek Janja Lamovšek Stegne 21, 1000 Ljubljana Plant Protection Department Hacquetova ulica 17 BION INSTITUTE Ltd. Agricultural Institute of Slovenia +38640490419 1000, Ljubljana linda.ogrizek@gmail.com +386 (0)1 280 52 00 janja.lamovsek@kis.si Franci Čuš Agricultural Institute of Slovenia Department of Fruit Growing Viticulture and Oenology Hacquetova ulica 17 1000, Ljubljana +386 (0)1 280 52 43 franc.cus@kis.si Marija Gorjanc University of Ljubljana Faculty of Natural Sciences and Engineering Chair of Textile and Clothing Engineering Aškerčeva 12 1000, Ljubljana +386 (0)1 200 32 56 marija.gorjanc@ntf.uni-lj.si 60 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION VEGAN LEATHER WALLET MADE WITH APPLE WASTE Ismet Ege Kalkan1, Günseli Aksoy Oral3, Ayşegül İlkentapar2, Figen Temiz-Dişlioğlu2, 3 Nurcan Tiryaki , Sena Şahin 3 and Umut Kivanc Sahin 1 1Department of Textile Engineering, Istanbul Technical University, Turkye 2Vakko, Business Development Department, Turkye 3Vakko, Nakkaştepe Design Center, Turkye Abstract: Vegan leather wallets represent an innovative and ethical alternative to traditional leather goods, align-ing with the growing demand for sustainable and cruelty-free products. This abstract explores the composition, benefits, and market impact of vegan leather wallets. Made from various plant-based or synthetic materials, such as cork, pineapple leaves, and recycled plastics, vegan leather offers comparable durability and aesthetic appeal to animal leather without the associated environmental and ethical concerns. The adoption of vegan leather in the fashion industry reflects a significant shift towards eco-conscious consumerism, driven by awareness of animal rights and environmental sustainability. This trend is supported by advancements in material technology, enabling the production of high-quality, versatile vegan leather products. Vegan leather wallets exemplify this shift, offering consumers stylish, functional, and ethical options that contribute to a more sustainable future. In this novel study we have produced a synthetic vegan leather with apple waste. We have tested the wallet for crocking and abra-sion resistance on denim pants. Results showed that in the crouching fastness it is in the accepted area but it can be improved abrasion resistance showed that there was no change in color in the wallet or in the denim. Also there were no damages in both. Key words: Synthetic Leather, Vegan, Sustainability, Accessory 1. INTRODUCTION Scientific researchers and the footwear business have been following the slow but steady progress toward devel-oping leather substitutes over the past few decades, which has resulted in the creation of a variety of synthetic and natural materials. The fashion industry, with its constantly shifting trends and fashions, does its best to draw in customers by providing reasonably priced goods, but most consumers are unaware that this business is a major contributor to global pollution due to its vast waste output. Furthermore, the growing production of leather fashion items from natural resources like animal pelts is progressively turning into a serious problem for sustainability for both present and future generations. As a result, creating eco-friendly products and developing other sources are crucial (Saha,2020). Luxury brands who want to integrate sustainability into their business practices; these brands target millennial consumers who are concerned about the environment (Rolling, 2020). As a result, many fashion brands concen-trate on developing substitutes for animal goods. This kind of activity will undoubtedly boost sales and upset the current social order. The desire to improve animal rights and welfare is what drives the creation of alternative ma-terials, which is a sustainable indicator for businesses looking to expand while simultaneously taking care of the environment (Choi, 2021). With these concerns we have studied ways to both have the sustainable and cruel-free approach and to have a good garment quality as normal leather products. We have used polyester as base fabric and used polyurethane-waste from apple processing for the outer of the wallet. For several reasons, urethane adhesives offer better adhesion (Eling, 2004). They may successfully saturate nearly any substrate’s surface. Because of hydrogen bonding, they engage in polar interactions with the surface. They can penetrate the majority of porous substrates due to their small molecular size or low molecular weight. They also create covalent connections with substrates that contain hydrogen atoms in an active state. Adhesive 61 29–30 May 2025, Ljubljana, Slovenia stiffness, adhesive strength, elasticity, and cross-linking can therefore be adjusted to meet certain demands and specifications by adjusting the molecular makeup and type of polyurethane glue used (Fitzgerald, 2013). 2. DESIGN AND EXPERIMENTAL The vegan leather wallet emphasizes sustainability, durability, and security, appealing to environmental-ly aware consumers who prioritize aesthetics and utility. Apple leather, the principal material, is sourced from waste generated by the apple industry, thereby diminishing environmental impact while provid-ing a soft, high-quality texture akin to conventional leather. A layer of PU (polyurethane) coating is ap-plied to augment durability and ensure endurance, offering resistance to wear, dampness, and daily use while preserving a lightweight structure. The design adopts a minimalist and ergonomic approach, in-corporating many card slots for convenient access and organization while maintaining a slim profile. For the future we are planning to put an RFID-blocking layer, composed of a thin but efficient conductive fabric or aluminum shielding, is seamlessly incorporated between the material layers to thwart unlawful scanning and data theft. This functionality is especially advantageous for consumers possessing contactless payment cards or digital access keys. The manufacturing process emphasizes low-impact dyes, non-toxic adhesives, and energy-efficient production techniques, thereby guaranteeing an ethical and sustainable supply chain. The cardholder features meticulous stitching and edge-sealing methods to improve its durability while preserving a sophisticated, contem-porary appearance. The product, encased in recyclable or biodegradable materials, corresponds with a sustain-able lifestyle, rendering it an optimal selection for anyone desiring a fashionable, environmentally conscious, and reliable daily accessory. We have our material from VAKKO company. The material are 18% PL, 43% PU(polyurethane) and 39% WAP(waste of apples) 2.1 Methods Coagulation The support is first impregnated with a mixture of PU and Apple waste. The coagulation process starts after when the impregnated fabric goes in the water with DMF solvent. After the material is coagulated it is washed to be cleaned from all the solvent residuals. Then is finally dried in the ovens. The coagulation process allows the production of synthetic leather with breathable and aesthetic effects that make it very similar to authentic leather. Coating This process can be separated in 3 layers: - first Pu or PU/APPLE layer (preskin) coated directly onto the release paper; this will be the visible one that must have the highest resistance to scratching, flexion, wear and tear -a second and a third PU layer (skin or body), coated directly onto the previous layers -a final glue layer to stick the textile support or coagulated material whose function is to act as reinforcement. Embossing The texture of the material given by the cylinder in the embossing machine. 2.2 Testing Testing of the material has been done with their standarts as crocking fastness ISO 105-X12 with SDL Atlas M238AA and abrasion resistance ISO 12947 modified with Nu-Martindale abrasion and pilling tester. The modifi-cation is changing the abrasion cloth with denim to see the effect of the wallet to the fabric. 62 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS AND DISCUSSION Crocking fastness results for Melavir sample Dry 3-4 and for wet 3. The results are in the acceptable region but improvements can be made. Abrasion resistance results are shown below on Figure 1. A) B) C) Figure 1: Abrasion resistance of the studied samples: A) Before test, B) Denim Fabric after test, C) Leather after test After 20.000 revolutions there were no breakage on the wallet and there were no damage or color changes on the denim fabric. 4. CONCLUSIONS In conclusion, the journey towards developing sustainable and cruelty-free leather alternatives has made signif-icant strides, driven by the fashion industry’s need to address its environmental impact. The use of innovative materials such as polyester base fabric combined with polyurethane waste from apple processing exemplifies the creative approaches being taken to produce high-quality synthetic leather. This process, involving multiple layers and advanced techniques like coagulation, yields a material that closely resembles genuine leather in both aesthetics and functionality. Our testing results, including crocking fastness and abrasion resistance, indicate that the synthetic leather created through this method meets industry standards. However, there is always room for improvement, and continuous refinement of these materials will ensure even better performance and greater acceptance in the market. Ultimately, the development of eco-friendly leather alternatives is a vital step towards a more sustainable fashion industry. By reducing reliance on animal products and minimizing environmental impact, we can pave the way for a future where fashion and sustainability coexist harmoniously. For future of this study we are going to try different approaches to waste and try to incorparete functionality as anti-theft to contactless payments 63 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES: Choi, Y. H. and Lee, K. H. 2021. “Ethical Consumers’ Awareness of Vegan Materials: Focused on Fake Fur and Fake Leather.” Sustainability 13 (1): 436. Eling, B. and Phanopolous, C. 2004. Polyurethane Adhesives and Binders. Greenwood Village, CO: Poisindex, Micromedex. Fitzgerald, K. T. and Bronstein, A. C. 2013. “Polyurethane Adhesive Ingestion.” Topics in Companion Animal Medicine 28 (1): 28–31. Rolling, V., Seifert, C., Chattaraman, V. and Sadachar, A. 2020. “Pro-Environmental Millennial Consumers’ Responses to the Fur Conundrum of Luxury Brands.” International Journal of Consumer Studies 44 (6): 1–14. Saha, N., Ngwabebhoh, F. A., Nguyen, H. T. and Saha, P. 2020. “Environmentally Friendly and Animal Free Leather: Fabrication and Characterization.” In AIP Conference Proceedings, Vol. 2289, No. 1. Melville, NY: AIP Publishing. ADDITIONAL DATA ABOUT AUTHOR Corresponding author: Co-author(s): Istanbul Technical University Vakko Nakkaştepe Design Center Vakko Nakkaştepe Design Center Altunizade, Kuşbakişi Cd. No:35, İsmet Ege Kalkan Günseli Aksoy Oral Sena Şahin Department of Textile Engineering Altunizade, Kuşbakişi Cd. No:35, 34662 Üsküdar İstanbul 34662 Üsküdar İstanbul İTÜ Gümüşsuyu Kampüsü İnönü Cad. No:65, 34437 Gümüşsuyu Ayşegül İlkentapar Umut Kivanç Şahin Beyoğlu - İstanbul / Türkiye Vakko Business Development Department Istanbul Technical University, Koza, 1673. Sok No:125, Department of Textile Engineering +905323954387 34510 Esenyurt/İstanbul İTÜ Gümüşsuyu Kampüsü, kalkani15@itu.edu.tr İnönü Cad. No:65, 34437 Gümüşsuyu, Figen Temiz-Dişlioğlu Beyoğlu - İstanbul / Türkiye Vakko Business Development Department Koza, 1673. Sok No:125, 34510 Esenyurt/İstanbul Nurcan Tiryaki Vakko Nakkaştepe Design Center Altunizade, Kuşbakişi Cd. No:35, 34662 Üsküdar İstanbul 64 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION CHARACTERIZATION OF MELT-EXTRUDED PA 6 FILAMENTS MODIFIED WITH ZnO NANOPARTICLES Anja Ludaš Dujmić1, Sanja Ercegović Ražić1, Andrea Jurov2, 3 Bernarda Marković , Nino Dimitrov 3 and Ivona Vidić Štrac 3 1University of Zagreb, Faculty of Textile Technology, Croatia 2Jožef Stefan Institute, Slovenia 3Croatian Institute of Public Health, Croatia Abstract: This study investigates the potential of ZnO-modified polyamide 6 (PA 6) fibres produced by melt spin-ning to support sustainable textile production. Melt spinning, a chemical spinning technique, is an efficient and cost-effective method to incorporate active nanoparticles into polymer fibres. Recycled PA 6 fibres were modified with ZnO nanoparticles (ZnO NPs) in concentrations of 0.1 to 2.0 wt % of the polymer. Morphological analysis by SEM showed the successful incorporation of the ZnO NPs, which appear as white, irregular structures on the filament surfaces, with the surface roughness increasing at higher concentrations. Elemental analysis by ICP-MS confirmed that the concentrations and sizes of the ZnO NPs were within the expected range. This approach is in line with environmental goals as it combines recycled materials with functional improvements for high performan-ce applications. Keywords: melt spinning, recycled PA 6, ZnO NPs, SEM microscopy, ICP-MS spectroscopy 1. INTRODUCTION In recent years, the textile industry has increasingly focused on sustainable production methods due to techno-logical advances, growing environmental concerns and stricter legal requirements. Global challenges such as climate change and the depletion of natural resources have led the industry to adopt the principles of the circular economy, which focus on reducing waste, recycling materials and maximising the use of resources (Chen et al., 2021). As one of the biggest polluters, the textile industry faces particular challenges. It needs to reduce its carbon footprint, manage textile waste and develop materials that meet both performance and sustainability standards (Vollmer et al., 2020). As part of this effort, melt spinning has emerged as one of the most promising techniques to promote sustainable textile production. This cost-effective and versatile chemical spinning process facilitates the integration of active particles directly into polymer fibres, enabling the production of functionalized textiles in a streamlined and effi-cient manner (Hufenus et al., 2020). Melt spinning not only supports the incorporation of additives, but also ena-bles the use of recycled raw materials, making it an ideal technology for addressing environmental concerns (Kim et al., 2024). By simplifying the production process and reducing energy consumption, this method meets modern sustainability goals while delivering high-performance textile products (Zhang et al., 2023). Polyamide 6 (PA 6), a thermoplastic polymer widely used in the textile industry, plays a central role in this transfor-mation. PA 6 is known for its exceptional mechanical properties, including durability, wear resistance and chemical stability, and is particularly well suited to recycling processes (Zhang et al., 2014). The possibility of reusing PA 6 waste into high-quality fibres underlines its importance in the development of sustainable textile solutions (Kim et al., 2024). However, as consumer demand shifts towards multifunctional materials that offer additional properties beyond durability, there is an increasing need to improve the inherent properties of PA 6 (Zhang et al., 2022). Nanotechnology offers innovative solutions to improve polymer functionality, with zinc oxide nanoparticles (ZnO NPs) emerging as an important additive for textile applications. ZnO NPs offer a range of beneficial properties, in- 65 29–30 May 2025, Ljubljana, Slovenia cluding antibacterial activity, odour absorption and UV protection, which are highly desirable for hygiene-sensitive applications such as sportswear, outdoor protective clothing and medical textiles (Verbič et al., 2019). In addition, ZnO NPs contribute to the development of textiles that are both high-performance and environmentally friendly, as they enable the production of functional fibres with minimal ecological impact (Ludaš Dujmić et al., 2024). The integration of ZnO NPs into recycled PA 6 fibres through melt spinning represents a significant advance in the field of sustainable textiles. This approach not only extends the life cycle of polymer materials, but also increases their value by providing additional functionalities (Bashal et al., 2022). By meeting the dual goals of performance and sustainability, ZnO-modified PA 6 fibres have the potential to transform the textile industry and adapt it to the growing demand for environmentally friendly and multifunctional products (Vitchuli et al., 2011). 2. EXPERIMENTAL To investigate the potential of ZnO NPs to improve the properties of recycled polyamide 6 polymer filaments, a series of experiments were conducted using the melt spinning technique and different concentrations of ZnO NPs. 2.1 Materials and methods Recycled polyamide polymer granulate (PA 6) obtained by recycling fishing net waste and purchased from the company AquafilSLO, Ljubljana (Slovenia), was used for the study. Prior to extrusion, 600 g of PA 6 polymer was dried at a temperature of 80 °C for 24 hours. ZnO nanoparticles (Alfa Aesar GmbH&Co), size 40 - 100 nm, melting point 1975 °C, were added in 5 different ratios (0.1 %, 0.5 %, 1 %, 1.5 %, 2 %) to the weight of the PA 6 polymer. The extrusion process was carried out using a Rondol Bench Top 21 mm twin-screw extruder (Rondol Technology Ltd., Staffordshire, UK). Before adding PA 6 polymer and ZnO nanoparticles to the extruder charge, the parame-ters of the twin-screw extruder were optimized for the chemical melt spinning process (Table 1). Table 1: Optimization of a twin-screw extruder for chemical melt spinning Pressure Torque Screw Diameter Six Heating Zones Cooling medium 0.7–2.0 bar 50–80 rpm 21 mm 1st zone: 220 °C, Water 2nd to 5th zones: 230 °C 6th zones: 233 °C After the extrusion process, the samples were analyzed with a scanning electron microscopy (SEM) using the Prisma E microscope (Thermo Fisher Scientific Inc., Waltham, MA, USA) to gain insight into the morphological properties of the samples. For the analysis of the samples with the scanning electron microscope, gold was vapor-deposited in order to obtain an electrically conductive sample on which the rays could be reflected. The morphological view of the samples was created at a magnification of 1600x and 8100x. Polymer granules treated with ZnO NPs and untreated polymer granules were brought into contact with the si-mulant ultrapure water at a mass-to-volume ratio of 5 g = 0.1 l at 40 °C for 10 days. After the migration test, the samples were homogenized for 30 minutes at room temperature in an ultrasonic bath with ZnO NPs and charac-terized using the Agilent 7900 single quadrupole mass spectrometer (ICP-MS) (Santa Clara, USA), instrument operational parameters are shown in Table 2. For the measurement of total Zn, the samples were subjected to microwave digestion. The samples were digested by microwave digestion in the Multiwave PRO sample digestion and extraction system (Anton Paar, Austria). The digestion amount for polymer granulate samples was 0.2 g. The reagent used was a mixture of 5.0 ml ultrapure water, 2.0 ml nitric acid (ultra trace 69%, Scharlau) and 1.0 ml hydrogen peroxide (suprapur 30%, Merck). After digestion, the samples were filtered with filter paper (blue tape) and diluted to 25 ml in volumetric flasks and analy-zed in the Agilent 7900 ICP-MS. Two silver dispersions with different lot numbers (MKCH0301 and MKCK6165) of standard reference materials were used to characterize the ZnO particles to confirm the accuracy of the method. 66 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Single particle ICP-MS (spICP-MS) was used to characterize the ZnO NPs dispersed or suspended in ultrapure water. Elemental signals of individual ZnO particles were detected using the spICP-MS instrument, which allows the simultaneous determination of particle number and size distribution as well as concentrations of particles and Single particle ICP-MS (spICP-MS) was used to characterize the ZnO NPs dispersed or suspended in ultrapure dissolved elements. water. Elemental signals of individual ZnO particles were detected using the spICP-MS instrument, which allows the simultaneous determination of particle number and size distribution as well as concentrations of particles and dissolved elements. Table 2: Instrument operational parameters of the Agilent 7900 ICP-MS Table 2: Instrument operational parameters of the Agilent 7900 ICP-MS RF power Sampling Carrier Sample Spray Dwell Masses Data acqui- RF power (W) depth Sampling gas (L/ Carrier uptake rate Sample chamber Spray time (µs) Dwell monitored Masses sition time Data (W) (mm) depth min) gas (mL/min) uptake rate temp. (°C) chamber time (µs) monitored (s/element) acquisition (mm) (L/min) (mL/min) temp. (°C) time 1550 (s/element) 8 1.05 0.31 2 100 66 Zn 60 1550 8 1.05 0.31 2 100 66 Zn 60 3. RESULTS AND DISCUSSION 3. RESULTS AND DISCUSSION optimized extrusion parameters and precise integration of nanoparticles to achieve tailored material properties. ZnO nanoparticles in defined weight fractions (t.2.1). The process demonstrates the effective combination of optimized extrusion parameters and precise integration of nanoparticles to achieve tailored material properties. Figure 1 shows the resulting filaments, which were photographed with a Dino-Lite digital microscope at 60x Figure 1 shows the resulting filaments, which were photographed with a Dino-Lite digital microscope at 60x magnification. ZnO nanoparticles in defined weight fractions (t.2.1). The process demonstrates the effective combination of Five different filaments were produced by extruding recycled polyamide polymer granules (PA 6), incorporating Five different filaments were produced by extruding recycled polyamide polymer granules (PA 6), incorporating magnification. a) PA6/ 0.1 % ZnO b) PA6/ 0.5 % ZnO c) PA6/ 1 % ZnO d) PA6/ 1.5 % ZnO e) PA6/ 2 % ZnO Figure 1. Figure 1. Produced filaments photographed with a Dino-Lite digital microscope at 60x magnification Produced filaments photographed with a Dino-Lite digital microscope at 60x magnification obtain detailed insights into the surface properties of the material. In contrast to the raw PA 6 polymer sample, sample, which has a relatively smooth and uniform surface, the morphological SEM analysis shows distinct which has a relatively smooth and uniform surface, the morphological SEM analysis shows distinct features relat-features related to the incorporation of ZnO NPs. These nanoparticles appear as white, irregularly shaped ed to the incorporation of ZnO NPs. These nanoparticles appear as white, irregularly shaped structures distributed structures distributed over the filament surfaces. With increasing ZnO concentration, The morphological examination of the samples was carried out at magnifications of 1600x and 8100x in order to to obtain detailed insights into the surface properties of the material. In contrast to the raw PA 6 polymer The morphological examination of the samples was carried out at magnifications of 1600x and 8100x in order remarkable changes in over the filament surfaces. With increasing ZnO concentration, remarkable changes in surface morphology can surface morphology can be observed. The filament surfaces show an increased relief and a significant increase be observed. The filament surfaces show an increased relief and a significant increase in surface roughness, in surface roughness, indicating the interaction between the polymer matrix and the nanoparticles (Figure 2). indicating the interaction between the polymer matrix and the nanoparticles (Figure 2). At higher concentrations At higher concentrations of nanoparticles, the formation of agglomerates characterized by clusters of ZnO of nanoparticles, the formation of agglomerates characterized by clusters of ZnO particles randomly dispersed particles randomly dispersed over the polymer surface becomes evident. This random dispersion contributes over the polymer surface becomes evident. This random dispersion contributes to the heterogeneity of the surface to the heterogeneity of the surface texture and emphasizes the challenge of achieving a uniform distribution texture and emphasizes the challenge of achieving a uniform distribution of nanoparticles at high concentrations. of nanoparticles at high concentrations. The elemental analysis after the migration test at 40 °C for 10 days, the results (Figure 3) showed good agreement The e lemental analysis a fter the migration test at 40 °C for 10 days, the results (Figure 3) showed good with the ZnO NPs embedded in the polymer. The measured concentration of ZnO NPs in the sample with 0.1% agreement with the ZnO NPs embedded in the polymer. The measured concentration of ZnO NPs in the ZnO was 56 000 ng/L, 0.5% ZnO was 83 000 ng/L, 1% ZnO was 105 000 ng/L, 1.5% ZnO was 155 000 ng/L and sample with 0.1% ZnO was 56 000 ng/L, 0.5% ZnO was 83 000 ng/L, 1% ZnO was 105 000 ng/L, 1.5% ZnO increased to a concentration value of 192 000 ng/L in the sample with 2.0% ZnO. Furthermore, the mean size of was 155 000 ng/L and increased to a concentration value of 192 000 ng/L in the sample with 2.0% ZnO. the ZnO NPs was 63.5 – 95 nm, depending on the embedded concentration in the polymer material. The obtained Furthermore, the mean size of the ZnO NPs was 63.5 – 95 nm, depending on the embedded concentration in results showed a good correlation with the reported size range of the ZnO NPs (40 - 100 nm). Based on the results the polymer material. The obtained results showed a good correlation with the reported size range of the ZnO obtained, it can be assumed that the migration conditions at 40 °C for 10 days are more suitable for the migration NPs ( 40 - 100 nm). Based on the results obtained, it can be assumed that the migration conditions at 40 °C of nanoparticles from this type of polymer. for 10 days are more suitable for the migration of nanoparticles from this type of polymer. 3 67 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia a) PA 6 extruded c) PA 6/ 0.5 % ZnO b) PA 6/ 0.1 % ZnO a) PA 6 extruded b) PA 6/ 0.1 % ZnO c) PA 6/ 0.5 % ZnO d) PA 6/ 1.0 % ZnO e) PA 6/ 1.5 % ZnO f) PA 6/ 2.0 % ZnO Figure 2. Morphological SEM analysis of PA 6 polymer, extruded with different concentrations of ZnO nanoparticles; a) d) PA 6/ 1.0 % ZnO e) PA 6/ 1.5 % ZnO f) PA 6/ 2.0 % ZnO Figure 2. magnification of 1600x, b-f) 8100x Morphological SEM analysis of PA 6 polymer, extruded with different concentrations of ZnO nanoparticles; a) magnification of 1600x, b-f) 8100x a) PA 6/ 0.1 % ZnO b) PA 6/ 0.5 % ZnO c) PA 6/ 1 % ZnO d) PA 6/ 1.5 % ZnO e) PA 6/ 2 % ZnO Figure 3. Figure 3. Particle size distribution of ZnO nanoparticles in ultrapure water extract: a) - e); 0.1 % - 2 % ZnO Particle size distribution of ZnO nanoparticles in ultrapure water extract: a) - e); 0.1 % - 2 % ZnO after migation during after migation during 10 days at 40 °C 10 days at 40 °C 4. CONCLUSION The study successfully demonstrated the production of filaments from recycled polyamide (PA 6) with different concentrations of ZnO NPs using optimized extrusion parameters. Morphological SEM analyzes confirmed 68 4 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSION The study successfully demonstrated the production of filaments from recycled polyamide (PA 6) with different concentrations of ZnO NPs using optimized extrusion parameters. Morphological SEM analyzes confirmed that the incorporation of ZnO nanoparticles significantly altered the surface properties of the filaments, with increased surface relief and roughness observed with increasing nanoparticle concentration. At higher concentrations, the formation of agglomerates made it clear how difficult it is to achieve a uniform distribution of the ZnO NPs. The migration tests showed a direct correlation between the concentration of ZnO NPs embedded in the polymer and their release under controlled conditions. The measured concentrations of ZnO NPs in the migration medium ranged from 56,000 ng/L for the sample with 0.1 % ZnO to 192,000 ng/L for the sample with 2.0 % ZnO. The mean size of the ZnO NPs (63.5 – 95 nm) matched well with the expected range, indicating a consistent particle size distribution. These results suggest that migration conditions of 40 °C for 10 days are particularly effective for evaluating the release of nanoparticles from PA 6-based polymers. The results provide valuable insights into the potential for tailoring the material properties, release behaviour of nanoparticles in recycled polymers, and support their appli-cation in the development of advanced materials. 5. REFERENCES Bashal, A.H. et al. 2022. “Bio-Based (Chitosan-ZnO) Nanocomposite: Synthesis, Characterization, and Its Use as Recyclable, Ecofriendly Biocatalyst for Synthesis of Thiazoles Tethered Azo Groups.” Polymers, 14(386): 1–10. Chen, X. et al . 2021. “Circular Economy and Sustainability of the Clothing and Textile Industry.” Mater Circ Econ 3(12): 1–9. Hufenus, R., Yan, Y., Dauner, M., Kikutani, T. 2020. “Melt-Spun Fibers for Textile Applications.” Materials 13(19): 1–32. Kim, K. et al. 2024. “Melt Spinnability Comparison of Mechanically and Chemically Recycled Polyamide 6 for Plastic Waste Reuse.” Polymers 16(3152): 1–14. Ludaš Dujmić, A. et al. 2024. “Characterization of Melt-Spun Recycled PA 6 Polymer by Adding ZnO Nanoparticles during the Extrusion Process.” Polymers 16(1883): 1–13. Verbič, A., Gorjanc, M., Simončič, B. 2019. “Zinc Oxide for Functional Textile Coatings: Recent Advances”. Coatings 9(9): 1–26. Vitchuli, N., et al. 2011. “Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning–electrospraying hybrid process for use in protective applications.” Science and Technology of Advanced Materials 12(5): 1–7. Vollmer, I. et al. 2020. “Beyond Mechanical Recycling: Giving New Life to Plastic Waste.” Angew. Chem. Int. Ed. 59(15402): 1-22. Zhang, D. 2014. Advances in Filament Yarn Spinning of Textiles and Polymers, Cambridge, UK: Woodhead Publishing. Zhang, S. et al. 2022. “Preparing cationic dyeable polyamide 6 filaments by combining the masterbatch technique with melt copolymerization. ” Textile Research Journal 92(3-4): 511–524. Zhang, S., Wu, Y., Ji, P., Ran, Q., Wang, H., Chen, B. and Wang, C. 2023. “Sustainable Production of Polyamide 6 Fibers: Direct Melt Spinning and Efficient Reuse of Residual Oligomers during Polymerization.” ACS Sustainable Chemistry & Engineering 11(9): 3789–3800 69 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHOR Corresponding author: Co-author(s): Anja Ludaš Dujmić Sanja Ercegović Ražić Nino Dimitrov Faculty of Textile Technology Faculty of Textile Technology Division for environmental health Department of Materials, Department for General Use Items Department of Materials, University of Zagreb University of Zagreb Croatian Institute of Public Health Fibres and Textile Testing Fibres and Textile Testing Rockefellerova 7 Prilaz baruna Filipovića 28a 10 000 Zagreb, Croatia Prilaz baruna Filipovića 28a 10 000 Zagreb, Croatia nino.dimitrov@hzjz.hr 10 000 Zagreb, Croatia sanja.ercegovic@ttf.unizg.hr Ivona Vidić Štrac anja.ludas@ttf.unizg.hr Andrea Jurov Croatian Institute of Public Health Jožef Stefan Institute Division for environmental health Department of Gaseous Electronics Department for General Use Items Jamova Cesta 39 Rockefellerova 7 1000 Ljubljana, Slovenia 10 000 Zagreb, Croatia andrea.jurov@ijs.si ivona.vidic-strac@hzjz.hr Bernarda Marković Croatian Institute of Public Health Division for environmental health Department for General Use Items Rockefellerova 7, 10 000 Zagreb, Croatia bernarda.markovic@hzjz 70 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION UV RADIATION PROTECTION OF COTTON AND WOOL FUNCTIONALISED WITH HOP LEAVES Sebastijan Šmid1, Nika Pirš1, Klara Močenik1 and Marija Gorjanc1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: In this research, wool and cotton fabrics were bio-mordanted with pomegranate peel extract and sub-sequently dyed with hop leaf extracts. The extracts were prepared using either crushed or ground leaves in tap or distilled water. Dyeing was performed after the bio-mordanting process. The textile samples were analysed for their colour using a reflectance spectrophotometer and their transmittance in the ultraviolet (UV) range using a UV/Vis spectrophotometer. The results revealed that bio-mordanting enhanced the colour yield of the dyed fabrics, leading to a higher ultraviolet protection factor (UPF) and classification in the excellent protection catego-ry. Additionally, the preparation method of the extract proved to be crucial, as crushed hop leaves extracted in tap water yielded the best dyeability and functional properties of the fabrics. Keywords: cotton, wool, bio-mordanting, eco-finishing, food waste, pomegranate peels, hop leaves, UV protec-tion. 1. INTRODUCTION Increasingly strict environmental regulations and legislations in the field of environmental protection are boosting the use of natural ingredients. People have become more environmentally and health conscious and many are looking for products that help protect the environment, reduce the global problem of pollution, and use products in their lives that are sustainable and toxin-free. It is crucial to focus on environmentally friendly processes that are in line with EU priorities with Zero pollution action plan and the Chemicals strategy for sustainability. Pomegranate peel extract can serve as both a dyeing agent and a bio-mordant (Bouaziz, 2021; Hosseinnezhad, 2022; Mansour, 2022; Shahid, 2019). The peel is a rich source of tannins, punicalins, punicalagins, gallic acid, and ellagic acid (Shahid, 2019). When used as a bio-mordant, it can induce colour changes in wool dyed with weld, particularly at higher concentrations (Hosseinnezhad, 2022). However, in the case of dyeing wool with madder, it does not affect the coloration (Hosseinnezhad, 2022). Batool et al. (Batool, 2023) compared the use of mineral mordants and bio-mordants for cotton fabric and found that pomegranate peel extract yielded the best results when dyeing with eggplant waste. To date, no published research has explored dyeing or finishing textiles with hop leaves, despite findings on the polyphenol compounds present in hop leaves extracts prepared with ethanol, methanol, and etha-nol-water mixtures (80:20) (Abram, 2015; Chiancone, 2023; Čeh, 2007; Muzykiewicz, 2019). The major phenolics in hop leaves include flavanol glycosides with quercetin, kaempferol glycosides, and chlorogenic acid (Chiancone, 2023). These compounds contribute to the antioxidant and antibacterial properties of hop leaf extracts. The aim of our research was to develop sustainable bio-based textiles with UV-protective properties using extracts derived from food waste products, specifically pomegranate peel as a bio-mordant and hop leaves extract as a dyebath. 2. EXPERIMENTAL 2.1 Material For the research raw wool (171.6 g/m2; 32 warp/cm, 24 weft/cm; WO) and raw, scoured cotton (128 g/m2; 55 warp/ cm, 37 weft/cm; CO) fabrics were used. Hop leaves were collected at The Slovenian institute of hop research and brewing, Žalec, Slovenia. 71 29–30 May 2025, Ljubljana, Slovenia 2.2 Bio-mordant preparation and fabric functionalisation Bio-mordanting was performed by using pomegranate peels (cleaned, dried and grinded). Hot distilled water was poured over 2 g/l of pomegranate peels, extracting at boiling for 5 minutes, left to cool and macerate for 24 hours at room temperature. After the mixture was filtered, the resulting extract was used for bio-mordanting of WO and CO in GyroWash 815 (James Heal, UK), with the liquor to goods ratio (L:G) equal to 40:1, at 60 °C, for 30 min. The samples were wrung and left to air dry. 29–30 May 2025, Ljubljana, Slovenia 2.3 Hop leaves extract preparation and fabric dyeing Hop leaves extract was prepared by pouring hot distilled or hard water over 40 g/L dried and grinded or crushed of WO and CO in GyroWash 815 (James Heal, UK), with the liquor to goods ratio (L:G) equal to 40:1, at 60 leaves. This was followed by extracting at boiling temperatures for 5 min and left to cool for 30 min. After filtration ° C, for 30 min. The samples were wrung and left to air dry. the extracts were used for dyeing unmordanted and bio-mordanted WO and CO samples in Gyrowash, at L:G = 40:1, temperature 60 2.3 Hop leaves extract preparation and fabric dyeing ° C, for 60 min. The samples were rinsed with hard or distilled water, wrung and left to air dry. The marking of samples is presented in Table 1. Hop leaves extract was prepared by pouring hot distilled or hard water over 40 g/L dried and grinded or crushed leaves. This was followed by extracting at boiling temperatures for 5 min and left to cool for 30 min. After filtration the extracts were used for dyeing unmordanted and bio-mordanted WO and CO samples in Gyrowash, Table 1: Marking of WO and CO samples according to the treatment at L:G = 40:1, temperature 60 ° C, for 60 min. The samples were rinsed with hard or distilled water, wrung and Wool marking Extraction water Hop leaves left to air dry. The marking of samples is presented in Table 1. Table 1: Cotton marking Bio-mordanting for hop leaves preparation Marking of WO and CO samples according to the treatment WO_raw CO_raw N/A N/A N/A N/A stands for not applicable WO_bio Hop leaves CO_bio Yes N/A N/A Wool marking Cotton marking Bio-mordanting Extraction water for hop leaves preparation WO_T_G CO_T_G No WO_raw CO_raw N/A N/A Grinded N/A WO_B_T_G CO_B_T_G Yes WO_bio CO_bio Yes N/A N/A Tap WO_T_C CO_T_C No WO_T_G CO_T_G No Crushed Grinded WO_B_T_C WO_B_T_G CO_B_T_C CO_B_T_G Yes Yes Tap WO_T_C CO_T_C No WO_D_G CO_D_G No Crushed Grinded WO_B_T_C CO_B_T_C Yes WO_B_D_G CO_B_D_G Yes WO_D_G CO_D_G No Distilled WO_D_C CO_D_C No Grinded WO_B_D_G CO_B_D_G Yes Crushed Distilled WO_B_D_C CO_B_D_C Yes WO_D_C CO_D_C No Crushed WO_B_D_C CO_B_D_C Yes N/A stands for not applicable All textile samples were analysed for their colour and colour yield using reflectance spectrometer Spectro 1050, All textile samples were analysed for their colour and colour yield using reflectance spectrometer Spectro 1050, with 9 mm aperture. Five measurements were taken for each fabric sample. The colour yield ( ∆ K/S) was with 9 mm aperture. Five measurements were taken for each fabric sample. The colour yield ( ∆ K/S) was calculat-calculated from reflectance measurements (R) of untreated and treated 2.4 Analysis 2.4 Analysis CO or WO sample, using equation 1: ed from reflectance measurements (R) of untreated and treated CO or WO sample, using equation 1: 𝐾𝐾𝐾𝐾 2 2 (1 − 𝑅𝑅𝑅𝑅 ) (1 − 𝑅𝑅𝑅𝑅 ) ∆ 𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈 𝑇𝑇𝑇𝑇 = � � − � � (1) 𝑆𝑆𝑆𝑆 2𝑅𝑅𝑅𝑅 𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈 2𝑅𝑅𝑅𝑅𝑇𝑇𝑇𝑇 where R is reflectance of untreated sample and R is the reflectance of treated sample. where R UN T UN is reflectance of untreated sample and R T is the reflectance of treated sample. The protection against UV radiation was determined using Lambda 850+ UV/Vis spectrometer (Perkin Elmer). The protection against UV radiation was determined using Lambda 850+ UV/Vis spectrometer (Perkin Elmer). The transmittance of UV radiation measurements and UV protection factor (UPF) calculations were performed The transmittance of UV radiation measurements and UV protection factor (UPF) calculations were performed according to the AATCC 183 test method (AATCC 2020). We performed six measurements (at 0°, 45°, and 90°) according to the AATCC 183 test method (AATCC 2020). We performed six measurements (at 0°, 45°, and per sample. The UV protection factor (UPF) was calculated according to the equation 2: 90°) per sample. The UV protection factor (UPF) was calculated according to the equation 2: ∑400 𝐸𝐸𝐸𝐸 (𝜆𝜆𝜆𝜆) ∙ 𝑆𝑆𝑆𝑆(𝜆𝜆𝜆𝜆) 𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈 290 = (2) ∑400 𝐸𝐸𝐸𝐸(𝜆𝜆𝜆𝜆) ∙ 𝑆𝑆𝑆𝑆(𝜆𝜆𝜆𝜆) ∙ 𝑇𝑇𝑇𝑇(𝜆𝜆𝜆𝜆) 290 72 The UPF values were determined based on the AS/NZ 4399:2017 standard, which determines the effectiveness of textile protection against UV rays. Protection is classified into three categories – minimal, good and excellent. Values below 15 mean insufficient UV protection, values between 15 and 30 minimal UV where RUN is reflectance of untreated sample and RT is the reflectance of treated sample. The protection against UV radiation was determined using 29–30 May 2025, Ljubljana, Slovenia Lambda 850+ UV/Vis spectrometer (Perkin Elmer). The transmittance of UV radiation measurements and UV protection factor (UPF) calculations were performed according to the AATCC 183 test method (AATCC 2020). We performed six measurements (at 0°, 45°, and 90°) per sample. The UV protection factor (UPF) was calculated according to the equation 2: ∑400 𝐸𝐸𝐸𝐸 (𝜆𝜆𝜆𝜆) ∙ 𝑆𝑆𝑆𝑆(𝜆𝜆𝜆𝜆) 𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈 290 = (2) ∑400 𝐸𝐸𝐸𝐸(𝜆𝜆𝜆𝜆) ∙ 𝑆𝑆𝑆𝑆(𝜆𝜆𝜆𝜆) ∙ 𝑇𝑇𝑇𝑇(𝜆𝜆𝜆𝜆) 290 The UPF values were determined based on the AS/NZ 4399:2017 standard, which determines the effectiveness The UPF values were determined based on the AS/NZ 4399:2017 standard, which determines the Values below 15 mean insufficient UV protection, values between 15 and 30 minimal UV protection, between 30 and excellent. Values below 15 mean insufficient UV protection, values between 15 and 30 minimal UV protection, between 30 and 50 good UV protection, and above 50 excellent UV protection. of textile protection against UV rays. Protection is classified into three categories – minimal, good and excellent. effectiveness of textile protection against UV rays. Protection is classified into three categories – minimal, good and 50 good UV protection, and above 50 excellent UV protection. 3. RESULTS WITH DISCUSSION The CIELAB colour coordinates of textile samples are presented in Table 2. The results show that bio-mordant-2 ing with pomegranate peel extract decreases the CIE L* values of the samples, meaning they become darker. Bio-mordanting also affects the CIE a* and b* values: WO becomes redder and yellower (both values increase), while CO becomes yellower (only the CIE b* value changes). This trend continues after dyeing, as bio-mordanted dyed samples are darker, redder, and yellower compared to unmordanted dyed samples. The type of water used (distilled or tap) for preparing hop leaves extracts significantly influences the colour of dyed CO and WO, with the effect being more pronounced for CO. The CO dyed with hop leaves extract prepared using tap water appears much darker, slightly redder, and slightly yellower compared to CO dyed with hop leaves extracts prepared using distilled water. For WO, dyeing with extracts prepared with tap water slightly darkens the samples, causes a minor shift towards the red axis, and significantly increases yellowing. The method of preparing the hop leaves (using crushed or ground leaves) for extraction also affects the colour of the dyed samples. Using ground hop leaves results in slightly lighter and yellower coloration of CO, while WO samples exhibit darker coloration regardless of the type of water used for extract preparation. Table 2: CIELAB colour coordinates of WO and CO samples Sample CIE L* CIE a* CIE b* CO_raw 87.80 1.24 10.06 CO_bio 84.06 1.00 15.69 CO_T_G 75.62 5.42 16.12 CO_B_T_G 69.53 6.45 22.12 CO_T_C 75.01 5.06 18.64 CO_B_T_C 69.17 5.83 22.92 CO_D_G 77.03 4.76 17.85 CO_B_D_G 71.13 5.88 22.74 CO_D_C 76.32 4.54 17.28 CO_B_D_C 69.79 5.84 22.69 WO_raw 87.20 -0.40 13.51 WO_bio 79.39 2.16 16.74 WO_T_G 75.32 3.82 20.07 WO_B_T_G 69.88 4.81 23.77 WO_T_C 72.37 4.96 21.40 WO_B_T_C 68.31 4.85 24.37 WO_D_G 75.88 3.23 21.70 WO_B_D_G 70.89 4.17 23.52 WO_D_C 74.84 2.97 20.88 WO_B_D_C 69.12 4.25 23.72 73 29–30 May 2025, Ljubljana, Slovenia The ∆K/S value of dyed CO and WO samples was calculated by comparing untreated and treated samples (i.e., raw/mordanted and dyed/undyed), and the results are presented in Figure 1. The ∆K/S values align with the CIELAB coordinates shown in Table 2. Bio-mordanting enhances the colour yield, with a more pronounced effect observed in samples dyed with hop leaves extract prepared using tap water compared to distilled water. Figure 29–30 May 2025, Ljubljana, Slovenia 1 also reveals that hop leaves extracts exhibit a better affinity towards WO fabrics than towards CO fabrics. Additionally, using crushed rather than ground leaves for extract preparation results in a higher colour yield, regardless of the substrate or the type of water used for extract preparation. Figure 1: ∆K/S of CO and WO dyed with hop leaves extract Figure 1: ∆K/S of CO and WO dyed with hop leaves extract The influence of using either crushed or ground hop leaves for dyeing is more evident in the functional The influence of using either crushed or ground hop leaves for dyeing is more evident in the functional properties samples. The lowest properties of textiles. Table 3 presents the UV protection factor (UPF) and protection category of the textile of textiles. Table 3 presents the UV protection factor (UPF) and protection category of the textile samples. The UV radiation. All other samples demonstrated either good or excellent UV protection. Bio-mordanting and UPF value, 11.40, was observed for raw CO, which provides insufficient protection against lowest UPF value, 11.40, was observed for raw CO, which provides insufficient protection against UV radiation. dyeing significantly enhanced UV protection, with the most pronounced increases in UPF values found in All other samples demonstrated either good or excellent UV protection. Bio-mordanting and dyeing significantly samples dyed with extracts prepared from crushed hop leaves, regardless of the type of water used for enhanced UV protection, with the most pronounced increases in UPF values found in samples dyed with extracts extraction. prepared from crushed hop leaves, regardless of the type of water used for extraction. Table 3: UV protection factor (UPF), transmittance in UVA and UVB (%), UVA and UVB blocking (%) and protection category of CO and WO samples. Sample UVA UVB UVA UVB Protection UPF transmittance transmittance blocking blocking category (%) (%) (%) (%) CO_raw 11.40 14.71 7.34 85.29 92.66 Insufficient CO_bio 52.22 3.29 1.42 96.71 98.58 Excellent CO_T_G 39.46 4.44 2.11 95.56 97.89 Good CO_B_T_G 118.00 1.62 0.70 98.38 99.30 Excellent CO_T_C 54.80 3.23 1.53 96.77 98.47 Excellent CO_B_T_C 131.72 1.41 0.63 98.59 99.37 Excellent CO_D_G 40.11 4.43 2.08 95.57 97.92 Good CO_B_D_G 105.02 1.76 0.79 98.24 99.21 Excellent CO_D_C 48.23 3.86 1.73 96.14 98.27 Good CO_B_D_C 115.86 1.64 0.72 98,36 99.28 Excellent WO_raw 59.10 9.70 0.56 90.30 99.44 Excellent WO_bio 119.15 3.12 0.43 96.88 99.57 Excellent WO_T_G 121.93 3.47 0.37 96.53 99.63 Excellent WO_B_T_G 201.35 1.71 0.27 98.29 99.73 Excellent WO_T_C 181.36 2.23 0.26 97.77 99.74 Excellent 74 WO_B_T_C 255.79 1.31 0.22 98.69 99.78 Excellent WO_D_G 120.77 3.42 0.39 96.58 99.61 Excellent 29–30 May 2025, Ljubljana, Slovenia Table 3: UV protection factor (UPF), transmittance in UVA and UVB (%), UVA and UVB blocking (%) and protec-tion category of CO and WO samples. Sample UVA transmit UVA UVB -UVB transmit- Protection UPF blocking blocking tance (%) tance (%) category (%) (%) CO_raw 11.40 14.71 7.34 85.29 92.66 Insufficient CO_bio 52.22 3.29 1.42 96.71 98.58 Excellent CO_T_G 39.46 4.44 2.11 95.56 97.89 Good CO_B_T_G 118.00 1.62 0.70 98.38 99.30 Excellent CO_T_C 54.80 3.23 1.53 96.77 98.47 Excellent CO_B_T_C 131.72 1.41 0.63 98.59 99.37 Excellent CO_D_G 40.11 4.43 2.08 95.57 97.92 Good CO_B_D_G 105.02 1.76 0.79 98.24 99.21 Excellent CO_D_C 48.23 3.86 1.73 96.14 98.27 Good CO_B_D_C 115.86 1.64 0.72 98,36 99.28 Excellent WO_raw 59.10 9.70 0.56 90.30 99.44 Excellent WO_bio 119.15 3.12 0.43 96.88 99.57 Excellent WO_T_G 121.93 3.47 0.37 96.53 99.63 Excellent WO_B_T_G 201.35 1.71 0.27 98.29 99.73 Excellent WO_T_C 181.36 2.23 0.26 97.77 99.74 Excellent WO_B_T_C 255.79 1.31 0.22 98.69 99.78 Excellent WO_D_G 120.77 3.42 0.39 96.58 99.61 Excellent WO_B_D_G 226.26 1.48 0.25 98.52 99.75 Excellent WO_D_C 138.56 2.88 0.35 97.12 99.65 Excellent WO_B_D_C 270.92 1.31 0.20 98.69 99.80 Excellent 4. CONCLUSIONS Using crushed hop leaves for extract preparation results in higher colour yield and improved UV protection for both CO and WO compared to ground leaves, particularly when the extract is prepared with tap water instead of distilled water. These effects are further enhanced when functionalisation is performed on bio-mordanted samples. 5. ACKNOWLEDGEMENT The research was performed as part of the master’s degree Planning textiles and clothing study programme, course Eco-finishing. 6. REFERENCES Abram, V., Čeh, B., Vidmar, M., Hercezi, M., Lazić, N., Bucik, V., Smole Možina, S., J. Košir, I., Kač, M., Demšar, L., Poklar Ulrih, N. 2015. “A comparison of antioxidant and antimicrobial activity between hop leaves and hop cones.” Industrial Crops and Products 64: 124-134. Batool, F., Iqbal, N., Adeel, S., Azeem, M., Mumtaz, S. and Hussaan, M. 2023. “Exploration of natural colourant of (Solanum melongena L.) brinjal plant residues for fabric dyeing: a novel approach towards textile processing.” Natural Poroduct Research: 1-7. Bouaziz, A., Dridi, D., Gargoubi, S., Chelbi, S., Boudokhane, C., Kenani, A. and Aroui, S. 2021. “Analysis of the Coloring and Antibacterial Effects of Natural Dye: Pomegranate Peel.” Coatings 11 (1277): 1−9. Chiancone, B., Guarrasi, V., Leto, L., Del Vecchio, L., Calani, L., Ganino, T., Galaverni, M. and Cirlini, M. 2023. “Vitro-derived hop (Humulus lupulus L.) leaves and roots as source of bioactive compounds: antioxidant activity and polyphenolic profile.” Plant Cell, Tissue and Organ Culture 153: 295-306. 75 29–30 May 2025, Ljubljana, Slovenia Čeh, B., Kač, M., J. Košir, I., Abram, V. 2007. “Relationships between Xanthohumol and Polyphenol Content in Hop Leaves and Hop Cones with Regard to Water Supply and Cultivar.” International Journal of Molecular Sciences 8: 989-1000. Hosseinnezhad, M., Gharanjig, K., Rouhani, S., Razani, N. and Imani, H. 2022. “Environmentally friendly dyeing of wool yarns using of combination of bio-mordants and natural dyes.” Environmental Progress & Sustainable Energy 41 (5): 1-9. Shahid, M., Islam, S., Rather, L, J., Manzoor, N. and Mohammad, F. 2019. “Simultaneous shade development, antibacterial, and antifungal functionalization of wool using Punica granatum L. Peel extract as a source of textile dye.” Journal of Natural Fibers 16 (4): 555−556. Mansour, R., Dhouib, S. and Sakli, F. 2022. “UV Protection and Dyeing Properties of Wool Fabrics Dyed with Aqueous Extracts of Madder Roots, Chamomiles, Pomegranate Peels, and Apple Tree Branches Bark.” Journal of Natural Fibers 19 (2): 610−620. Muzykiewicz, A., Nowak, A., Zielonka-Brzezicka, J., Florkowska, K., Duchnik, W., Klimowicz, A. 2019. “Comparison of antioxidant activity of extracts of hop leaves harvested in different years.” Herba Polonica 65 (3): 1-9. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Marija Gorjanc Sebastijan Šmid Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering University of Ljubljana University of Ljubljana Chair of Textile Chair of Textile and Clothing Engineering and Clothing Engineering Aškerčeva 12 Aškerčeva 12 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia ss99047@student.uni-lj.si marija.gorjanc@ntf.uni-lj.si University of Ljubljana Faculty of Natural Sciences +38612003256 Nika Pirš and Engineering Chair of Textile and Clothing Engineering Aškerčeva 12 1000 Ljubljana, Slovenia np65501@stundent.uni-lj.si Klara Močenik University of Ljubljana Faculty of Natural Sciences and Engineering Chair of Textile and Clothing Engineering Aškrčeva 12 1000 Ljubljana, Slovenia km89154@student.uni-lj.si 76 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION PIGMENT PRINTING WITH DYE EXTRACTS FROM INVASIVE ALIEN PLANTS Maja Klančnik1 and Katarina Lampič1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The use of natural dyes in the dyeing and printing of textiles is becoming increasingly important, espe-cially when invasive alien plants that overgrow the land are used for their production. In our study, the dye extracts from the petals of the goldenrod, the leaves of the Japanese knotweed and the petals of the Himalayan balsam were used to produce screen printing inks. For comparison, the pigment printing paste with a pH value of 7.4, which was produced by mixing the individual ingredients, and the pigment printing paste with a pH value of 8.1, which is already commercially available, were used. The inks made from three dye extracts, which were produced with two different printing pastes, were printed on cotton and polyester fabrics using the flat screen printing pro-cess. The colour of the prints was evaluated spectrophotometrically and the resistance of the prints to rubbing, wet hot pressing, washing and light was tested. The research results confirmed that the inks produced with the two pigment printing pastes made from natural dyes can be successfully used for screen printing on fabrics. The prints produced with the yellow dye extract from goldenrod flowers showed the best fastness properties with even excellent light fastness. Keywords: natural dye, invasive alien plant, printing, cotton, polyester. 1. INTRODUCTION Interest in the use of natural dyes is increasing nowadays, as natural dyes derived from plants are non-toxic, sus-tainable and biodegradable and have many positive effects on human health (Rungruangkitkrai, 2012). Invasive alien plants pose an ecological problem as they quickly overgrow and displace native plants in a harmful way, which is why the possibility of using them as a source of natural dyes for dyeing and printing textiles has already been investigated (Gorjanc, 2016; Gorjanc, 2019; Klančnik, 2021; Klančnik, 2021; Klančnik, 2024; Topič, 2017). Our research tested the applicability of natural dyes extracted from three different invasive alien plants, namely the yellow petals of goldenrod, the green leaves of Japanese knotweed and the pink petals of Himalayan balsam, for screen printing on cotton and polyester fabrics as well as the influence of two printing pastes with slightly different pH values in the formulation of screen printing inks on the final colour of the prints and the fastness prop-erties to rubbing, wet hot pressing, washing and light. The printing paste with a pH value of 7.4 was produced by mixing an acrylic thickener and an acrylic binder in distilled water, while the printing paste with a pH value of 8.1 was already commercially available. Printing with dyes from Himalayan balsam (Klančnik, 2021) and Japanese knotweed leaves (Klančnik, 2024) has already been researched, but not printing with dyes from goldenrod and the use of printing pastes with different pH values in comparison. 2. EXPERIMENTAL 2.1 Dye extracts The dye extracts from the leaves of Japanese knotweed, form the petals of goldenrod and Himalayan Balsam were obtained from National Institute of Chemistry (Ljubljana, Slovenia). 77 29–30 May 2025, Ljubljana, Slovenia 2.2 Printing Ink Preparation For the screen printing inks, the already commercially prepared pigment printing paste Transparent Elastil FGI (AchitexMinerva Ltd., Vaiano Cremasco, Italy) with a pH value of 8.1 was used and the printing paste, which we prepared by mixing the individual ingredients according to the following recipe: 150 g Binder SE conc. (Achitex-Minerva Ltd., Vaiano Cremasco, Italy), 18 g thickener Clear MCS (AchitexMinerva Ltd., Vaiano Cremasco, Italy) and up to 1000 g demineralized water to form a homogeneous paste with a pH value of 7.4. The dye extract from goldenrod petals was added in the following concentrations: 1 and 3 g per 100 g of the printing paste we produced with a pH value of 7.4 and per 100 g of the commercially available Transparent Elastil printing paste with a pH value of 8.1. The dye extracts from the Japanese knotweed leaves and Himalayan balsam petals were added in concentrations of 1 and 3 g per 100 g of Transparent Elastil printing paste with a pH value of 8.1 and in a concentration of 3 g per 100 g of the printing paste with a pH value of 7.4. The formulated inks are shown in Figure 1. Figure 1: The printing inks produced with dye extracts from goldenrod (in the first row), with dye extracts from Japanese knotweed leaves (in the second row) and with dye extracts from Himalayan balsam (in the third row). 2.3 Printing Materials Cotton fabric (manufacturer Tekstina Ltd., Ajdovščina, Slovenia) in plain weave with a surface mass of 122.73 g/ m², hereinafter referred to as CO, and polyester fabric (supplier Luna Ltd., Ljubljana, Slovenia) in plain weave with a surface mass of 175.99 g/m², hereinafter referred to as PES, were used for printing. 2.4 Printing The printing inks were applied to fabrics using the semi-automatic screen-printing machine SD 05 (RokuPrint Ltd., Darmstadt, Germany) with the flat printing screen made of polyester fabric with 77 threads/cm and a thread diameter of 55 µm with three strokes of squeegee. The prints were dried at room temperature overnight and then cured at 150 °C for 5 minutes. 2.5 Spectrophotometric Measurements Colour measurements of the prints were made using the Eye-One i1 Pro spectrophotometer (X-Rite, Grand Rap-ids, MI, USA) with 45/0 plane geometry, illuminant D65, 10° standard observer and a 4.5 mm diameter aperture. The CIELAB colour coordinates: L* (lightness), a* (red-green value), b* (yellow-blue value) in the range of 380 to 730 nm were measured, the average of three measurements for each print was taken, and h (hue) and C* abab (chroma) were calculated. 2.6 Colour Fastness Tests The fastness of prints on fabrics to dry and wet rubbing was tested with the electronic Crocmeter M2388 rub tester (SDL Atlas, Rock Hill, SC, USA) according to ISO 105-X12: 2016. The resistance of printed ink on fabrics to wet hot pressing was tested according to ISO 105-X11: 1996. The fastness of the prints on fabrics to domestic 78 29–30 May 2025, Ljubljana, Slovenia and commercial laundering was tested according to ISO 105-C06: 2010 - test A1S at 40 °C for 30 minutes in the standard washing machine Launder-O-meter (Atlas, Rock Hill, SC, USA). The colour loss of the prints and the staining on the white adjacent fabrics after the tests were visually evaluated using the grey scales according to ISO 105-A02: 1993 and ISO 105-A03: 2019, respectively with ratings from 1 to 5, with 5 being the best value. The colour fastness of the prints to artificial light (xenon arc fading lamp) was tested according to ISO 105-B02: 2014 using the Xenotest Alpha tester (Atlas, Rancho Cucamonga, CA, ZDA) under the following conditions: 35 °C, 35% relative humidity and 72 h, together with the standard blue reference scale. The colour change of the exposed prints was visually assessed using the blue wool references with ratings from 1 to 8, with 8 being the best value. 3. RESULTS WITH DISCUSSION The prints produced with inks made from the yellow dye extract from goldenrod petals were light yellow. The inks had a pleasant floral scent. More yellow and more intense prints were obtained with the ink made with the printing paste with a pH value of 8.1 than with the printing paste with a pH value of 7.4. The prints on cotton fabric were also more intense and more yellow than the prints on polyester fabric, as shown in Table 1. Table 1: Colour values of prints produced with goldenrod dye extract Colour values 1 g/100 g paste of 3 g/100 g paste of 1 g/100 g paste of 3 g/100 g paste of pH 7.4 pH 7.4 pH 8.1 pH 8.1 On cotton fabric L* 92.26 91.63 91.73 91.01 a* -1.81 -2.76 -2.76 -4.77 b* 6.92 10.51 10.50 21.56 C* 7.15 10.87 10.86 22.08 ab h (°) 104.66 104.71 104.73 102.48 ab On polyester fabric L* 89.69 90.22 88.53 91.22 a* -0.93 -1.34 -3.55 -3.86 b* -0.21 2.07 10.41 16.01 C* 0.95 2.47 11.00 16.47 ab h (°) 192.72 122.92 108.83 103.56 ab The prints produced with both printing pastes on both fabrics showed excellent dry and wet rub fastness as well as excellent wet iron fastness (grade 5), as shown in Table 2. The wash fastness of the prints at 40 °C was very good on cotton fabric with both pastes (grade 4-5), also on polyester fabric with the printing paste of pH 8.1, but only moderate (grade 3-4) with the printing paste of pH 7.4. The light fastness of the prints on cotton fabric was excellent (grade 8), but the light fastness on polyester fabric was only excellent when using the printing paste with pH 7.4, with the printing paste of pH 8.1 the prints faded strongly (grade 4). 79 29–30 May 2025, Ljubljana, Slovenia Table 2: Fastness properties of prints made with goldenrod dye extract Fastness 1 g/100 g 3 g/100 g 1 g/100 g 3 g/100 g paste of pH paste of pH paste of pH paste of pH 7.4 7.4 8.1 8.1 On cotton fabric Dry rubbing 5 5 5 5 Wet rubbing 5 5 5 5 Wet ironing (staining wet fabric) 5 5 5 5 Wet ironing (staining dry fabric) 5 5 5 5 Wet ironing (colour change) 5 5 5 5 Washing (staining of fabric) 4 4 4-5 4-5 Washing (colour change) 4-5 5 4-5 5 Light fastness 8 8 7 8 On polyester fabric Dry rubbing 5 5 5 5 Wet rubbing 5 5 5 5 Wet ironing (staining wet fabric) 5 5 5 5 Wet ironing (staining dry fabric) 5 5 5 5 Wet ironing (colour change) 5 5 5 5 Washing (staining of fabric) 5 5 5 5 Washing (colour change) 4 3-4 4 4-5 Light fastness 8 8 5 4 The prints made with inks from the dye extract of Japanese knotweed leaves were yellowish-green. The prints made with the printing paste with a pH value of 8.1 on cotton fabric were more yellow and intense than prints made with the printing paste with a pH value of 7.4, which were greener (Table 3). The prints on cotton fabric were also more intense and more yellow than the prints on polyester fabric. 80 29–30 May 2025, Ljubljana, Slovenia Table 3: Colour values of prints produced with Japanese knotweed dye extract Colour values 1 g/100 g paste of 3 g/100 g paste of 1 g/100 g paste of 3 g/100 g paste of pH 7.4 pH 7.4 pH 8.1 pH 8.1 On cotton fabric L* / 79.09 85.53 73.18 a* / -1.28 -2.28 0.58 b* / 33.80 22.41 37.18 C* / 33.82 22.52 37.18 ab h (°) / 92.17 95.81 89.11 ab On polyester fabric L* / 75.48 83.21 61.77 a* / -0.12 -0.43 3.25 b* / 29.64 10.71 30.41 C* / 29.64 10.72 30.58 ab h (°) / 90.24 92.30 83.90 ab The prints produced with both printing pastes on both fabrics showed excellent dry rub fastness (grade 5), very good wet rub fastness (grade 4-5) and also wet iron fastness (grade 4-5), as shown in Table 4. The printing paste with a pH value of 8.1 showed half a level better wet rub fastness and iron fastness on cotton (grade 5). The wash fastness of the prints with the pH 8.1 printing paste was very good on both fabrics (grade 4-5), and grade 3-4 when the pH 7.4 printing paste was used. The prints with both printing pastes were very sensitive to light, the colour changed from yellowish-green to yellow on cotton fabric and to orange on polyester fabric (light fastness grade 2). 81 29–30 May 2025, Ljubljana, Slovenia Table 4: Fastness properties of prints made with Japanese knotweed dye extract Fastness 1 g/100 g 3 g/100 g 1 g/100 g 3 g/100 g paste of pH paste of pH paste of pH paste of pH 7.4 7.4 8.1 8.1 On cotton fabric Dry rubbing / 5 5 5 Wet rubbing / 4-5 5 5 Wet ironing (staining wet fabric) / 4-5 5 5 Wet ironing (staining dry fabric) / 5 5 5 Wet ironing (colour change) / 5 5 5 Washing (staining of fabric) / 4-5 4-5 4-5 Washing (colour change) / 3-4 4 5 Light fastness / 3 1 2 On polyester fabric Dry rubbing / 5 5 5 Wet rubbing / 4 5 5 Wet ironing (staining wet fabric) / 4-5 5 4-5 Wet ironing (staining dry fabric) / 4-5 5 5 Wet ironing (colour change) / 5 5 5 Washing (staining of fabric) / 5 5 5 Washing (colour change) / 4 3-4 4-5 Light fastness / 2 1 2 The prints obtained with inks made from the dye extract of Himalayan balsam petals with the printing paste of pH 7.4 were violet-brown and somewhat more intense than prints with the printing paste of pH 8.1, which were brown-er. The prints on cotton were slightly less intense at the higher dye concentration than on polyester (Table 5). 82 29–30 May 2025, Ljubljana, Slovenia Table 5: Colour values of prints produced with Himalayan balsam dye extract Colour values 1 g/100 g paste of 3 g/100 g paste of 1 g/100 g paste of 3 g/100 g paste of pH 7.4 pH 7.4 pH 8.1 pH 8.1 On cotton fabric L* / 77.12 86.75 78.96 a* / 5.42 0.30 2.55 b* / 12.43 8.35 11.46 C* / 13.56 8.36 11.74 ab h (°) / 66.44 87.94 77.45 ab On polyester fabric / L* / 67.19 83.97 75.75 a* / 8.29 0.93 3.02 b* / 12.23 3.44 12.60 C* / 14.78 3.56 12.96 ab h (°) / 55.87 74.87 76.52 ab The prints made with both printing pastes on both fabrics showed excellent fastness to dry rubbing and wet iron-ing (grade 5), still excellent wet rub fastness on cotton fabric and very good wet rub fastness on polyester fabric (grade 4-5), as shown in Table 6. The wash fastness of the prints on cotton with both printing pastes was moder-ate (grade 3), on polyester with the printing paste of pH 7.4 grade 2-3 and with the printing paste of pH 8.1 grade 1-2. The prints made with both pastes were also very sensitive to light and faded considerably at the higher dye concentration (light fastness grade 2-3). 83 29–30 May 2025, Ljubljana, Slovenia Table 6: Fastness properties of prints made with Himalayan balsam dye extract Fastness 1 g/100 g 3 g/100 g 1 g/100 g 3 g/100 g paste of pH paste of pH paste of pH paste of pH 7.4 7.4 8.1 8.1 On cotton fabric Dry rubbing / 5 5 5 Wet rubbing / 5 5 5 Wet ironing (staining wet fabric) / 4-5 5 5 Wet ironing (staining dry fabric) / 5 5 5 Wet ironing (colour change) / 5 5 5 Washing (staining of fabric) / 4-5 4-5 4-5 Washing (colour change) / 3 3-4 3 Light fastness / 3 6 3 On polyester fabric Dry rubbing / 5 5 5 Wet rubbing / 4-5 5 4-5 Wet ironing (staining wet fabric) / 4-5 5 5 Wet ironing (staining dry fabric) / 4-5 5 5 Wet ironing (colour change) / 5 5 5 Washing (staining of fabric) / 5 5 5 Washing (colour change) / 2-3 2 1-2 Light fastness / 2-3 5 2 4. CONCLUSION The research results confirmed that the printing inks produced with both pigment printing pastes made from nat-ural dyes can be successfully used for screen printing on fabrics. The different pH value of the printing paste also had a major influence on the colour hue and colour intensity of the prints as well as on the fastness properties, as the dye extracts contain many flavonoids whose structure depends on the pH value. The correct choice of print-ing paste must be made before printing according to the particular dye extract in order to achieve the best print quality. The prints made with the yellow dye extract from goldenrod flowers showed the best fastness properties with even excellent light fastness on cotton fabric with the both printing pastes and on polyester fabric when the printing paste with a pH value of 7.4 was used. 5. REFERENCES Gorjanc, M., Savić, A., Topalić-Trivunović, L., Mozetič, M.; Zaplotnik, R., Vesel, A., Grujić, D. (2016) ‘Dyeing of plasma treated cotton and bamboo rayon with Fallopia Japonica extract.’ Cellulose, 23, pp. 2221–2228. Gorjanc, M., Kert, M., Mujadžić, A., Simončič, B., Forte-Tavčer, P., Tomšič, B., Kostanjšek, K. (2019) ‘Cationic pretreatment of cotton and dyeing with Fallopia Japonica leaves.’ Tekstilec, 62, pp.181–186. Klančnik, M. (2021) ‘Screen Printing with Natural Dye Extract from Japanese Knotweed Rhizome.’ Fiber Polym., 22, pp. 2498–2506. Klančnik, M. (2021) ‘Printing with Natural Dye Extracted from Impatiens glandulifera Royle.’ Coatings, 11, pp. 445–457. Klančnik, M. (2024) ‘Printing with Natural Dye Extract from Japanese Knotweed Leaves.’ Fibers Polym., 25, pp. 4771–4785. Rungruangkitkrai, N, Mongkholrattanasit, R. (2012) In Proceedings of the International Conference: Textiles & Fashion. Bangkok, Thailand. Topič, T., Gorjanc, M., Kert, M. (2018) ‘The influence of the treatment process on the dyeability of cotton fabric using goldenrod dye.’ Tekstilec, 61, pp. 192–200. 84 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author: Maja Klančnik Katarina Lampič and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška 5 Snežniška 5 Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana 1000 Ljubljana 1000 Ljubljana, Slovenia Slovenia maja.klancnik@ntf.uni-lj.si 85 SMART AND FUNCTIONAL TEXTILES 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION POLYPROPYLENE NONWOVEN MATERIAL MODIFIED WITH (3-AMINOPROPYL) TRIALKOXYSYLOXANE AND Ag-BASED NANOPARTICLES Darka Marković1, Brigita Tomšič2, Vanja Tadić3, Tatjana Ilic-Tomic4, Barbara Simončič2 and Maja Radetić5 1University of Belgrade, Innovation Centre of the Faculty of Technology and Metallurgy, Serbia 2University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 3Institute for Medical Plant Research “Dr Josif Pančić”, Serbia 4University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Serbia 5University of Belgrade, Faculty of Technology and Metallurgy, Serbia Abstract: Pandemic COVID19 revealed the importance of face masks for the protection of medical staff and patients as well as the need for face masks with antimicrobial properties. To address this issue, nonwoven poly-propylene materials were impregnated with Ag-based nanoparticles after activation with corona discharge at at-mospheric pressure and modification with (3-aminopropyl) triethoxysilane (APTES). Ag-based nanoparticles were synthesized in situ on polypropylene nonwoven material using Cannabis sativa L., Cannabaceae (CS), and Pali-urus spina-christi Mill., Rhamnaceae (PSC) extracts. The amounts of synthesized Ag-based nanoparticles were sufficient to impart a strong antibacterial activity against Gram-negative bacteria Escherichia coli and Gram-posi-tive bacteria Staphylococcus aureus, and fungistatic properties against yeast Candida albicans. In addition, they were non-cytotoxic to HaCaT and MRC5 cells. Keywords: polypropylene, APTES, Ag nanoparticles, plant extract, antimicrobial activity. 1. INTRODUCTION The awareness of face masks importance significantly increased during the COVID-19 pandemic. They prevent the spreading of viral infections, the transfer of droplets, splashes, and sprays in healthcare settings, and they reduce exposure to airborne particulate matter. Face masks are usually made of nonwoven polypropylene (PP) materials. Taking into account a need for antimicrobial masks and the fact that PP fibers are chemically inert, the main goal of this study was to fabricate antimicrobial PP nonwoven material by in situ synthesis of Ag-based nanoparticles (NPs). This is very difficult due to chemical inertness and high hydrophobicity of PP fibers. To en-able the binding of Ag+-ions from AgNO solution, PP nonwoven fabric was activated with corona discharge at 3 atmospheric pressure and subsequently modified with (3-aminopropyl) triethoxysilane (APTES). Recently, the extracts of various plants (fruits, vegetables, and herbs) have become attractive for the metal NPs synthesis. The extracts of different parts of plants (root, leaves, flowers, fruits, barks, peels, shells, stems) contain flavonoids, terpenoids, alkaloids, and polyphenols recognized as efficient reducing, capping and stabilizing agents (Akintelu et al. 2020; Mali et al. 2020). However, there are only few studies reporting in situ biosynthesis of Ag-based NPs on textile fibers (Štular et al. 2021; Čuk et al. 2021). Thus, an effort has been made in this study to synthesize Ag-based NPs on PP nonwoven material using Cannabis sativa L., Cannabaceae (CS) and Paliurus spina-christi Mill., Rhamnaceae (PSC) extracts. 87 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL PP nonwoven material (40 g/m2) was treated with corona discharge at atmospheric pressure using a Vetaphone, Corona-Plus, type TF-415 device. The power was set to 700 W. The distance between the electrode and the fab-ric was adjusted to 2.2 mm. Both sides of the material passed through corona discharge 15 times. The coating procedure with APETES is described in literature (Marković et al. 2020). Briefly, a 4% (w/w) solution of hydrolyzed APTES precursor was prepared in ethanol and applied to corona-treated PP nonwoven fabric using the pad-dry-cure method, resulting in an add-on of 3.981.81%. These samples are labeled as CPP-APTES. The plant C. sativa and P. spina-christi extracts were prepared by adding 6.00 g of milled leaves in 100 mL of distilled water, and stirring at 80oC for 2 h. Prepared extracts were filtered and immediately used for the synthesis of Ag-based NPs. 0.25 g of CPP-APTES sample was immersed in 25 mL of 20 mM solution of AgNO for 2 h. 3 Afterwards, the sample was rinsed with deionized water and put in the plant extract. The synthesis was carried out at 60 oC for 1 h. After rinsing with distilled water, the samples were left to dry. The samples decorated with Ag-based NPs synthesized in the presence of C. sativa and P. spina-christi denoted CPP-APTES-Ag-CS and CPP-APTES-Ag-PSC, respectively. Chemical changes induced by corona treatment and modification with APTES were assessed by Fourier trans-form infrared spectroscopy (FTIR) in ATR mode using a Nicolet iS5 FTIR Spectrometer (Thermo Scientific) at 4 cm-1 resolution, in the wavenumber range 500–4000 cm-1. The morphology of fibers NPs was evaluated by field emission scanning electron microscopy (FE-SEM, Tescan Mira3 FEG). The size of NPs was determined by ana-lyzing the acquired FESEM images with the open-access imaging software, ImageJ.The total amount of Ag in all samples was measured by atomic adsorption spectroscopy (AAS, Spectra AA 55B, Varian). Antimicrobial activity of the samples with Ag-based NPs was tested against Gram-negative bacteria E. coli (ATCC 25922), Gram-positive bacteria S. aureus (ATCC 25923) and yeast C. albicans using a standard test method for determination of the antimicrobial activity of immobilized antimicrobial agents under dynamic contact conditions ASTM E 2149-01 (2001). Cytotoxicity of the samples with synthesized Ag-based NPs was evaluated on human keratinocyte cells (HaCaT cell line obtained from ATCC) and fibroblast cells (MRC5 cell line obtained from ATCC) using a MTT test. 3. RESULTS AND DISCUSSION The evaluation of chemical modifications resulting from corona and APTES treatments was conducted through FTIR spectroscopy (illustrated in Figure 1). The FTIR spectrum of PP sample displays bands that are characteris- asymmetric deformation vibrations or the CH scissor vibrations and the CH symmetric deformation vibrations 2 3 −1 (1457–1356 cm tic of PP, including the CH and CH asymmetric and symmetric stretching vibrations (2950–2830 cm−1), the CH 3 23 ), and the vibrations associated with C–C bonding (1200–800 cm−1) (Kostov et al. 2013). The corona treatment of PP samples led to the formation of two new bands at 1728 and 1642 cm−1, which are attribu-ted to carbonyl groups in aldehydes and ketones, as well as COO- asymmetric stretching vibrations, respectively (Kostov et al. 2013; Moldovan et al. 2016). The subsequent coating with APTES resulted in a diminished intensity of these bands (1728 cm−1 and 1642 cm−1). 88 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Figure 1: FTIR spectra of PP, CPP and CPP-APTES FESEM images shown in Figures 2 and 3 reveal that spherical, mostly single Ag-based NPs evenly covered the surface of both CPP-APTES-Ag-CS and CPP-APTES-Ag-PSC fibers. The average size of single NPs was 48±13 FESEM images shown in Figures 2 and 3 reveal that spherical, mostly single Ag-based NPs evenly covered agglomeration was apparent on the CPP-APTES-Ag-CS sample. The total content of silver on CPP-APTES-Ag-48±13 nm and 31±11 nm on CPP-APTES-Ag-CS and CPP-APTES-Ag-PSC fibers, respectively. However, evidence of agglomeration was apparent on the CPP-APTES-Ag-CS sample. The total content of silver on nm and 31±11 nm on CPP-APTES-Ag-CS and CPP-APTES-Ag-PSC fibers, respectively. However, the surface of both CPP-APTES-Ag-CS and CPP-APTES-Ag-PSC fibers. The average size of single NPs was evidence of of Ag on CPP-APTES-Ag-CS sample is attributed to larger NPs. CPP-APTES-Ag-CS and CPP-APTES-Ag-PSC samples were 1.52±0.35 mg/g and 1.08±0.27 mg/g, CS and CPP-APTES-Ag-PSC samples were 1.52±0.35 mg/g and 1.08±0.27 mg/g, respectively. A higher content respectively. A higher content of Ag on CPP-APTES-Ag-CS sample is attributed to larger NPs. Figure 2: Figure 2: FESEM image of CPP-APTES-Ag-CS fiber FESEM image of CPP-APTES-Ag-CS fiber 89 29–30 May 2025, Ljubljana, Slovenia Figure 2: FESEM image of CPP-APTES-Ag-CS fiber Figure 3: Figure 3:FESEM image of CPP-APTES-Ag-PSC fiber FESEM image of CPP-APTES-Ag-PSC fiber Antimicrobial activity of the control and modified samples is shown in Figure 4. The application of corona tre- coli 3 atment, both independently and in combination with APTES modification, resulted in a moderate decrease in E. bacterial colonies, achieving reductions of 82.5% and 88.9%, respectively. In contrast, the reduction of S. aureus was minimal, with values of 21.2% and 43.7%, respectively. Furthermore, samples treated with corona alone exhibited no antifungal properties, while the APTES modification yielded only a 7.67% reduction in the yeast C. albicans.The impregnation with Ag-based NPs imparted strong antibacterial activity to CPP-APTES fibers, in-dependently of the plant extract (bacteria reduction of 99.9%). In contrast to superior antibacterial activity against E coli and S. aureus, only fungistatic activity towards C. albicans was obtained. The percentage of HaCaT and MRC5 cells survival after 24 h long contact with sample extracts in comparison with native cells (control) was over 80%, implying that fabricated samples could be considered non-cytotoxic to these cells. Figure 4: Antimicrobial activity of the control and modified PP samples 90 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS This study showed that corona discharge at atmospheric pressure successfully activated PP fibers surface prior to modification with APTES, which provided functional groups for improved uptake of Ag+-ions. Spherical Ag-based NPs evenly distributed over the fiber surface were synthesized in the presence of C. sativa and P. spina-christi extracts. Fabricated nonwoven materials exhibited maximum antibacterial activity (99.9%) against E. coli and S. aureus, and fungistatic activity against yeast C. albicans. At the same time, they were non-cytotoxic towards HaCaT and MRC5 cells. Good antibacterial activity and non-cytotoxicity make developed materials an attractive candidate for the face masks production. 5. ACKNOWLEDGEMENT This work was financially supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Contract No. 451-03-136/2025-03/200287, 451-03-136/2025-03/200135) and by the Slove-nian Research and Innovation Agency (Programme P2-0213 Textiles and Ecology). 6. REFERENCES Akintelu, S.A., Folorunso, A.S., Folorunso, F.A., Oyebamiji, A.K. 2020. „Green synthesis of copper oxide nanoparticles for biomedical application and environmental remediation.“, Helyion 6: e04508. Čuk, N., Šala, M., Gorjanc, M. 2021. „Development of antibacterial and UV protective cotton fabrics using plant food waste and alien invasive plant extracts as reducing agents for the in-situ synthesis of silver nanoparticles.“ Cellulose 28: 3215-3233. Kostov, k.G., Nishime, T.M.C., Hein, L.R.O., Toth, A. 2013. „Study of polypropylene surface modification by air dielectric barrier discharge operated at two different frequencies.“ Surface and Coatings Technology 234: 60-66. Mali, S.C., Dhaka, A., Githala, C.K., Trivedi R. 2020. „Green synthesis of copper nanoparticles using Celastrus paniculatus Willd leaf extract and their photocatalytic and antifungal properties.“ Biotechnology Reports 27: e00518. Marković, D., Vasiljević, J., Ašanin, J., Ilić-Tomić, T., Jokić, B., Simončič, B., Mitrić, M., Mišić, D., Radetić, M. 2020. „The influence of coating with aminopropyl triethoxysilane and CuO/Cu O nanoparticles on antimicrobial activity of cotton fabrics under dark conditions.“ 2Journal of Applied Polymer Science 137: e49194. Moldovan, B., David, L., Achim, M., Clichici, S., Filip, G. A. 2016. „A green approach to phytomediated synthesis of silver nanoparticles using Sambucus nigra L. fruits extract and their antioxidant activity.“ Journal of Molecular Liquids 221: 271–278. Štular, D., Savio, E., Simončič, B., Šobak, M., Jerman, I., Poljanšek, I., Ferri, A., Tomšič, B. 2021. „Multifunctional antibacterial and ultraviolet protective cotton cellulose developed by in situ biosynthesis of silver nanoparticles into a polysiloxane matrix mediated by sumac leaf extract.“ Applied Surface Science 563: 150361. 91 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Maja Radeti Tatjana Ilic-Tomic ć Darka Marković Faculty of Technology Innovation Centre of the Institute of Molecular Genetics Faculty of Technology University of Belgrade University of Belgrade University of Belgrade and Metallurgy and Genetic Engineering Textile Engineering Department and Metallurgy Vojvode Stepe 444a Karnegijeva 4, 11000 Belgrade, Serbia Karnegijeva 4 11042 Belgrade, Serbia +38111 3976034 11000 Belgrade, Serbia +381 11 3303 613 tatjana.ilic-tomic@imgge.bg.ac.rs darka@tmf.bg.ac.rs +381 11 3303 613 Barbara Simončič Brigita Tomšič maja@tmf.bg.ac.rs University of Ljubljana University of Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering Chair of Textile Chair of Textile and Clothing Engineering and Clothing Engineering Snežniška ulica 5 Snežniška ulica 5 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia +386 1 20 03 231 +386 1 20 03 233 barbara.simoncic@ntf.uni-lj.si brigita.tomsic@ntf.uni-lj.si Vanja Tadić Institute for Medical Plant Research “Dr Josif Pančić” Tadeuša Košćuška 1 11000 Belgrade, Serbia +381 11 3031 650 vtadic@mocbilja.rs 92 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION MULTIFUNCTIONAL TiO BASED COATINGS 2 FOR ADVANCED TEXTILE APPLICATIONS Mohammad Mamunur Rashid1, Barbara Simončič1, Ivan Jerman2 1 and Brigita Tomšič 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2 National Institute of Chemistry, Slovenia Abstract: This study presents a sustainable approach to the development of multifunctional nanocomposite coat-ings for textiles by combining TiO with various organofunctional trialkoxysilane precursors. An optimised 4% tita-2 nium isopropoxide (TTIP) served as the TiO source. Using in-situ low-temperature sol-gel and sol-gel/hydrother-2 mal methods, TiO was doped with Ag (Ag-TiO ) or coupled with reduced graphene oxide (rGO/ TiO ) and further 2 2 2 modified with (3-(trimethoxysilyl)propyl)ammonium chloride (SiQAC), aminopropyltriethoxysilane (APTES) and the phosphorus-based flame retardant TPMP. Ag-TiO enabled self-sterilisation, UV protection and photocatalytic 2 self-cleaning through the controlled release of Ag/Ag O. Functionalisation with TPMP/SiQAC or TPMP/APTES 2 influenced the formation of Ag species and multifunctionality via TiO /Ag/AgCl or TiO /Ag heterocomposites. The 2 2 introduction of rGO into the TPMP/APTES-modified TiO matrix provided a more environmentally friendly alter-2 native and delivered excellent multifunctional performance. These novel nanocomposite coatings offer promising routes for the sustainable advancement of technical textiles with customised functionalities for specific applica-tions. Keywords: cotton, titanium dioxide (TiO ), Ag loading, reduced graphene oxide (rGO), surface functionalization, 2 organofunctional trialkoxysilanes 1. INTRODUCTION The concepts of green and sustainable chemistry in the textile industry focus on the development and production of nanostructured multifunctional textiles using safe and environmentally friendly chemicals, processes and tech-nological approaches. The sol-gel technique is recognised as an environmentally friendly nanotechnology method for the synthesis of nanomaterials with different morphologies and plays a key role in the production of metal and metal oxide nanoparticles (NPs). These NPs or nanofilms contribute to the functionalisation of textiles by impart-ing unique protective properties while maintaining low processing costs and a controlled morphology. TiO is a well-established photocatalyst characterised by high chemical stability, non-toxicity and affordability 2 (Linsebigler et al., 1995). To improve its functional properties, surface modifications have been explored, with sol-gel precursors — especially organofunctional trialkoxysilanes — proving to be very effective. These hybrid compounds contain an organic functional group covalently bonded to a reactive trialkoxysilane unit and enable the functionalisation of the fibre surface by thin film deposition. Research shows that TiO NPs in combination with 2 organofunctional trialkoxysilanes can provide photocatalytic, water and oil repellent properties as well as antimi-crobial activity (Shaheen et al., 2019; Riaz et al., 2019). However, there are still some challenges in the development of functional coatings with organofunctional tri- alkoxysilanes. Previous studies have focussed on TiO coatings with a single silane precursor, which limits multi-2 functionality. In addition, TiO nanoparticles are often physically bound to polysiloxane hybrid films, which raises 2 concerns about the durability of such nanocomposite coatings due to a gradual release of the nanoparticles. The main objective of this research is to develop an innovative and sustainable approach to produce multifunc- tional nanocomposite textile finishes. This is achieved by modifying TiO surfaces by doping and coating with sil-2 ver (Ag), coupling with reduced graphene oxide (rGO) and incorporating selected organofunctional trialkoxysilane 93 29–30 May 2025, Ljubljana, Slovenia precursors. The aim is to increase the photocatalytic activity of TiO while ensuring chemical bonding between 2 modified TiO and the functional groups of the fibres to improve the durability of the nanocomposite coating. The 2 study focuses on cellulosic fibres, which are widely used in technical, medical, protective, sports and leisure tex-tiles. In order to achieve the main objective, the study was divided into the following sections: (i) Optimisation of the in situ synthesis method of TiO₂ at different TTIP concentrations; (ii) surface modification of Ag-doped TiO₂ using a binary mixture of sol-gel precursors — either (3-(trimethoxysilyl)propyl)ammonium chloride (SiQAC) and phosphorus-based flame retardant TPMP or aminopropyltriethoxysilane (APTES) and TPMP; (iii) coupling of TiO ₂ with rGO/GO followed by nanocomposite modification with a binary mixture of sol-gel precursors TPMP and APTES. 2. EXPERIMENTAL 2.1 Materials The alkaline-scoured, bleached and mercerized 100% cotton plain weave fabric with a weight of 120 g/m2 and a density of 50 and 30 threads/cm in warp and weft directions, respectively, was used. Trought experiment four sol–gel precursors were used: titanium isopropoxide (TTIP) (≥ 97.0 wt. %; Sigma Aldrich) as the TiO precursor; 2 silver nitrate (AgNO ; Sigma Aldrich) as the Ag precursor; 3-(trihydroxysilyl)propyl methylphosphonate, mono-3 sodium salt solution (TPMP, 50 wt. % in H O; Sigma Aldrich) as the flame retardant agent; dimethyloctadecyl 2 (3-(trimethoxysilyl) propyl)ammonium chloride (SiQAC, 40 wt. % in methanol; Sigma Aldrich) and (3-aminopropyl) triethoxysilane (APTES, 99 wt. %; Sigma Aldrich) as the antimicrobial biobarrier agents. The ethanol (concentra-tion ≥99.8%), the organic dye methylene blue (MB), Rhodamine Blue (RhB) and the acetic acid were supplied by Honeywell Research Chemicals (Seetze, Germany) and CARLO ERBA Reagents S.A.S (Barcelona, Spain), respectively. All reagents are of analytical grade and were used without further purification. 2.2 Preparation of TTIP sol and application procedure TiO nanosols were prepared by mixing TTIP in ethanol to obtain concentrations of 2, 4, and 6%. Into the TiO 22 nanosols glacial acetic acid was added dropwise under constant stirring, where the mass ratio between TTIP and glacial acid was set at 7:1. Detailed application process is explained in (Rashid et al., 2022a). Briefly, TiO₂ nano-sols were applied to cotton fabric using sol-gel pad-dry-cure, pad-hydrothermal, and exhaustion-hydrothermal methods. In the pad-based methods, cotton samples were impregnated with TiO₂ nanosols, padded to achieve 80±2% wet pick-up, and either dried and cured (pad-dry-cure; samples labelled 2S, 4S and 6S) or dried and hy-drothermally treated (pad-hydrothermal, samples labelled 2H, 4H, 6H). In the exhaustion-hydrothermal method, samples were immersed in TiO ₂ nanosols under constant stirring for 1 hour, padded, and hydrothermally treated (samples labeled 2E, 4E, 6E). For the purpose of comparison, commercial TiO was also applied to the cotton 2 fabric using the pad-dry-cure method. For the Ag-dopped TiO detailed application procedure is described in (Rashid et al., 2022b). Briefly, the cotton 2 samples were firstly modified to a 4% TiO nanosol following pad-dry- hydrothermal treatment, whereas AgNO 23 water solutions of different concentrations, i.e., 0.5, 1.0 and 2.0 mM was utilised during hydrothermal treatment. At the end, the samples were dried at 100 °C. For the modification of the Ag-loaded TiO sol mixtures of TTIP+TPMP+SiQAC and TTIP+TPMP+APTES were 2 prepared using an equimolar ratio (1:1:1) (Rashid et al., 2024a). TTIP (4%) was dissolved in ethanol, followed by TPMP, SiQAC or APTES, and a small amount of 0.1 M HCl, with stirring for two hours to complete hydrolysis. Cotton samples were immersed in the sol mixtures, padded (0.8 bar, 80±5% wet pick-up), air-dried, and hydro-thermally treated in a Starlet-2 DL 600 Plus (Komachine, Korea) at 120°C for 60 min, either in water or a 2 mM AgNO₃ bath (1:50 ratio), then rinsed and dried. The samples hydrothermally treated in water are labeled as TiO / 2 TPMP/SiQAC and TiO /TPMP/APTES, samples hydrothermally treated in a 2 mM AgNO ₃ bath are labeled as Ag/ 2 TiO /TPMP/SiQAC or Ag/TiO /TPMP/APTES. 2 2 For the in situ synthesis of rGO/TiO₂ nanocomposites modified with a combination of TPMP and APTES on sol-gel method was used (Rashid, 2024b). The sol-gel precursor mixture was prepared in a molar ratio of TTIP:TP-MP:APTES = 1:1:2. Ascorbic acid was used as the reducing agent for GO, which was used in two concentrations, 0.75 and 1.50 mg/ml. The treated samples were labelled as S-(TiO₂+APTES+TPMP/rGO-x), where x denotes the concentration of GO used. 94 29–30 May 2025, Ljubljana, Slovenia 2.3 Characterization Chemical and morphological changes in cotton fibres were analyzed using scanning electron microscopy (SEM; JSM-6060 LV, Jeol, Japan) and energy-dispersive X-ray spectroscopy (EDS; Thermo Fisher Scientific Quattro S, USA). Additionally, X-ray diffraction (XRD) analysis was performed using a PANalytical X’Pert PRO diffractometer (CuKα₁ = 1.5406 Å) equipped with a fully open X’Celerator detector (2.122° 2θ). The functional properties of the coated fabric were evaluated through UV transmittance measurements using a Lambda 800+ UV/Vis spectrophotometer (Perkin Elmer, UK) and calculation of the UV protection factor (UPF) according to EN 13758-1:2001. Photocatalytic self-cleaning activity was assessed by monitoring the discoloration of a 0.2 mM RhB dye solution or fading of an MB dye stain on cotton samples via spectrophotometric analysis. For RhB dye degradation, function-alized cotton samples were immersed in 4 mL of RhB solution and irradiated with daylight in a Q-SUN Xe-3-HSE chamber (Q-Lab, UK) for up to 4 hours at 1-hour intervals. The absorbance at λmax = 552.93 nm was recorded, and the remaining RhB concentration was determined using a pre-established calibration curve. Dye discoloration was expressed as the Ct/C0 ratio, where Ct and C0 represent the RhB concentrations after time “t” and at the initial time (t = 0), respectively. For MB dye stain degradation, TiO₂-treated cotton samples were stained with 0.05% methylene blue (MB) solution and exposed to a Xenotest Alpha instrument (Atlas, USA) equipped with a xenon arc lamp (300–400 nm, 0.8–2.5 kVA) for up to 180 minutes. Dye degradation was assessed based on the reflectance (R) of the samples, mea-sured using a Datacolor Spectraflash SF 600 spectrophotometer under D 65/10 illumination. Antibacterial performance was tested against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) in accordance with the ASTM E 2149-01. Flame retardancy and thermal stability were evaluated via simultaneous thermal analysis in air using the simul-taneous TGA/DSC1 analyser (Mettler Toledo, Schwerzenbach, Switzerland). In addition, vertical flame test was performed following DIN 53906 standard method. 3. RESULTS WITH DISCUSSION The concentration of TTIP and the deposition method significantly influence the absorption and distribution of TiO2 on cotton fibres (Figure 1a). The sol-gel method resulted in a TiO film on the fibre surface at all three TTIP con-2 centrations, while the sol-gel/hydrothermal method resulted in a combination of TiO particles and a continuous 2 film. Namely, SEM images of samples modified by the exhaustion/hydrothermal method showed no TiO₂ particles or film on the fibre surface, indicating penetration of TiO into the fibre interior. Regardless of the deposition meth-2 od, amorphous TiO was formed (Figure 1b). However, the application method influenced the optical properties of 2 amorphous TiO which were determined using Tauc plots and band gap energy (Eg) calculations (Figure 1c). In 2 this case a comparable TiO ₂ structure for the sol-gel/hydrothermal and exhaustion/hydrothermal methods to the commercial TiO₂ was observed, as these samples demonstrated similar Eg values. 95 29–30 May 2025, Ljubljana, Slovenia Figure 1: (a) EDS spectra and elemental mapping of TiO₂-treated cotton samples with corresponding UPF values, (b) XRD spectra, (c) Tauc plots of (αhν)ⁿ versus photon energy for n = 2, and (d) images of MB-stained samples before and after 90 minutes of illumination under a visible xenon arc lamp (1.67 W/cm²). The samples modified with synthesised TiO showed effective UV protection, with samples 2E and 4S exhibiting 2 the highest self-cleaning activity (Figure 1d). They achieved 80.0% and 79.9% methylene blue (MB) degradation, outperforming commercial TiO . These low-temperature in situ TiO 2₂ synthesis methods have great practical po-tential due to the lower energy and chemical requirements. For further studies on TiO doping to enhance photo-2 catalytic activity, the sol-gel/hydrothermal method with 4% TTIP sol was selected as it offers high UV protection and high self-cleaning efficiency. Doping TiO with small amounts of biocidal Ag has shown promise, as optimal Ag concentrations improve the 2 adhesion and distribution of TiO₂ particles on textile fibres while limiting the release of Ag ions from the Ag/TiO₂ complex. Results of previous research (Rashid et al., 2022b) has shown that the combination of TiO ₂ photocat-alytic activity and controlled release of the biocidal Ag/Ag O complex enabled highly effective self-sterilisation of 2 the modified cotton surface by inhibiting the growth of E. coli and S. aureus. Ag doping not only improved the antimicrobial properties, but also the UV protection and photocatalytic self-cleaning efficiency of TiO ₂, resulting in a 69% degradation of the model dye. Based on these results, the optimal AgNO ₃ concentration for TiO doping 2 was set at 2.0 mM, which ensures a synergistic effect between Ag and TiO . 2 In continuation of the research surface modification of Ag-doped TiO₂ was performed using a bicomponent mixture of organofunctional alkyltrialkoxysilanes: SiQAC and TPMP or APTES and TPMP in order to assess the influence of the bio-barrier’s chemical structure (SiQAC or APTES) on the functional properties of the modified samples as well as to confer improved thermo-oxidative stability of the modified cotton. The results are presented in Figure 2. 96 29–30 May 2025, Ljubljana, Slovenia Figure 2: (a) EDS spectra and elemental mapping of Ag-doped TiO₂-modified cotton samples, (b) UPF values of modified TiO₂- and Ag-doped TiO₂-treated cotton samples, (c) discoloration activity of RhB after 4 hours of solar illumination and (d) with corresponding char residue images. The TPMP/SiQAC sol led to the formation of a TiO₂/Ag/AgCl nanocomposite that exhibited exceptional photocat-alytic self-cleaning activity but did not provide sufficient UV protection (Figures 2a and 2b). In contrast, TPMP/ APTES led to the formation of a TiO /Ag nanocomposite (Rashid et al., 2023), ensuring excellent UV protection 2 due to the complementary activity of TiO₂ and Ag nanoparticles, but exhibited lower photocatalytic self-cleaning efficiency (Figure 2c). Namely in the TiO /Ag/AgCl composite, which forms a semiconductor-metal-semiconductor 2 heterojunction on the Ag/ TiO /TPMP/SiQAC sample, facilitates the transfer of photogenerated holes from Ag to 2 the valence band (VB) of AgCl, leading to the formation of highly reactive •OH species via photooxidation and the oxidation of Cl ⁻ to reactive Cl* (Rashid et al., 2022b). However, the generation of holes on Ag can be hindered by its electron cloud, limiting hole transfer to AgCl. In contrast, the TiO /Ag nanocomposite in Ag/TiO TPMP/APTES 2 2 forms a semiconductor-metal interface that generates •OH species only in the VB of TiO (Rashid et al., 2023), 2 resulting in a lower RhB photodegradation rate compared to TiO₂/Ag/AgCl. The deposition of Ag on TiO₂ enabled complete self-sterilisation of the cotton surface (data not shown), regard-less of the type of bio-barrier in the mixture. However, in combination with APTES, the Ag nanoparticles formed hindered the successful formation of a TPMP-derived char layer, which was not the case with the TPMP/SiQAC mixture. In this case, TPMP effectively triggered the dehydration of the cellulose during thermal degradation and stabilised the char layer at higher temperatures (Rasid et al., 2024a). In line with the principles of sustainability, TPMP/APTES-functionalised TiO₂ was combined with rGO/GO to re-place Ag in the TiO₂-based nanocomposite. The results showed that rGO/GO significantly improved the multifunc-tional protective properties of the nanocomposite film (Figure 3). The modified cotton samples provided excellent UV protection by improving UVA and UVB blocking capabilities while providing good photocatalytic self-cleaning properties due to the synergistic effect between rGO/GO and TiO . In addition, TiO 2₂ coupled with rGO/GO while ensured effective surface sterilisation and demonstrated improved thermo-oxidative stability compared to untreat-ed cotton, which was achieved by the successful formation of a TPMP-derived protective char layer (Rashid et al., 2024b). 97 29–30 May 2025, Ljubljana, Slovenia Figure 3: Functional UV-protective (a), self-cleaning (b) and antibacterial (c) properties of the cotton samples functionalised with modified rGO-coupled TiO and their corresponding TGA curves (d). 2 4. CONCLUSIONS A low-temperature in-situ sol-gel method using 4% TTIP enabled the formation of Ag-TiO film on fibre surfac-2 es, while the sol-gel/hydrothermal approach yielded both Ag-TiO particles and a continuous film. Although both 2 methods showed practical potential, the sol-gel/hydrothermal method was favoured due to its superior UV pro-tection and photocatalytic performance. Silver-loaded Ag-TiO was modified for the first time in situ with TPMP 2 and two bio-barrier forming trialkoxysilanes, SiQAC and APTES. These modifications influenced the formation of Ag species and thus modulated the overall multifunctional performance by developing TiO₂/Ag/AgCl or TiO₂/ Ag heterocomposites. The introduction of rGO into the TPMP/APTES-modified Ag-TiO system provided a more 2 sustainable alternative to Ag–TiO delivering excellent multifunctional properties. The resulting nanocomposite 2 coatings are promising for the sustainable development of technical textiles offering distinct advantages tailored to specific applications. Funding: This research was carried out as part of PhD thesis of Dr. M. M. Rashid and was founded by the Slo-venian Research and Innovation Agency (Programme P2-0213 Textiles and Ecology, Infrastructural Centre RIC UL-NTF). 5. REFERENCES Linsebigler, A. L., Lu, G., & Yates, J. T. 1995. “Photocatalysis on TiO surfaces: principles, mechanisms, and selected results.” Chemical 2 Reviews 95: 735–758. Rashid, M. M., Zorc, M., Simončič, B., Jerman, I. and Tomšič, B. 2022a. “In-situ functionalization of cotton fabric by TiO₂: the influence of application routes.” Catalysts 12 (11): 1–17. Rashid, M. M., Tomšič, B., Simončič, B., Jerman, I., Štular, D. and Zorc, M. 2022b. “Sustainable and cost-effective functionalization of textile surfaces with Ag-doped TiO₂/polysiloxane hybrid nanocomposite for UV protection, antibacterial and self-cleaning properties.” Applied Surface Science 595: 1–15. Rashid, M. M., Tomšič, B., Simončič, B., Jerman, I., Štular, D., Zorc, M. and Čelan Korošin, N. 2023. “In situ tailoring of Ag-doped TiO₂/ 98 29–30 May 2025, Ljubljana, Slovenia TPMP/cotton nanocomposite with UV-protective, self-sterilizing and flame-retardant performance for advanced technical textiles.” Polymer Degradation and Stability 216: 1–11. Rashid, M. M., Simončič, B., Zorc, M., Čelan Korošin, N., Jerman, I. and Tomšič, B. 2024a. “Sustainable in situ synthesis of silver/titanium dioxide/organofunctional trialkoxysilane nanocomposite coatings on cotton fabric to tailor superior multifunctional protective properties.” Surfaces and Interfaces 49: 1–16. Rashid, M. M., Zorc, M., Simončič, B., Jerman, I., & Tomšič, B. 2024b. “Ag doping and rGO coupling of TiO within polysiloxane matrix for 2 the ecofriendly development of high-performance cotton fabric.” Materials Science Forum 1117: 9-15. Riaz, S., Ashraf, M., Hussain, T., Hussain, M. T. and Younus, A. 2019. “Fabrication of Robust Multifaceted Textiles by Application of Functionalized TiO Nanoparticles.” 2Colloids and Surfaces A: Physicochemical and Engineering Aspects 581: 123799. Shaheen, T. I., Salem, S. S. and Zaghloul, S. 2019. “A new facile strategy for multifunctional textiles development through in situ deposition of SiO /TiO nanosols hybrid.” 2 2Industrial and Engineering Chemistry Research 58 (44): 20203–20212 ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Brigita Tomšič Mohammad Mamunur Rasid Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana, University of Ljubljana and Engineering Aškerčeva cesta 12 Aškerčeva cesta 12 1000, Ljubljana 1000, Ljubljana mamun444@gmail.com brigita.tomsic@ntf.uni-lj.si Barbara Simončič University of Ljubljana Faculty of Natural Sciences and Engineering Aškerčeva cesta 12 1000, Ljubljana barbara.simoncic@ntf.uni-lj.si Ivan Jerman National Institute of Chemistry Hajdrihova 19 1000 Ljubljana, Slovenia Ivan.jerman@ki.si 99 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION THE RESEARCH JOURNEY: INVESTIGATING THE ROLE OF TEXTILE PROPERTIES IN BACTERIAL ADHESION Nina Čuk1, Barbara Simončič1, Klara Kostajnšek1, Matejka Bizjak1, 2 Rok Fink and Brigita Tomšič 1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2University of Ljubljana, Faculty of Health Sciences, Slovenia Abstract: An interdisciplinary team from the University of Ljubljana, Slovenia, recently investigated the topic of bacterial adhesion to textiles. When reviewing the literature, the contradictory conclusions of the various articles became clear. For this purpose, the bacterial strain Escherichia coli, which is part of the normal human microbiota, was included as a test organism in this study. Different textile raw materials, namely cotton and polyester, were used as substrates. The chemical parameters of woven fabrics were analysed using Fourier Transform Infrared Spectroscopy. Additionally, some of the physical properties including thickness and mass per unit area were me-asured. Finally, bacterial adhesion was determined, and it was found that the material properties have a direct influence on bacterial adhesion, as the bacterial strain E. coli adheres more strongly to hydrophobic polyester than to hydrophilic cotton. In addition to the results for researchers, professors and other interested parties, this article also describes the research process as a practical example for young students. Keywords: young researcher’s perspective, interdisciplinary research journey, woven fabric, bacterial adhesion. Graphic abstract: 1. INTRODUCTION Bacterial adhesion to various materials is a complex and multifaced process that is not yet fully understood. When observing bacterial adhesion to different textile materials, this complexity is compounded by the interplay of two important and unpredictable factors. Firstly, as living microorganisms, bacteria exhibit different adhesion mecha-nisms that are influenced by their physiological state and environmental conditions. Secondly, textiles are char-acterised by unique physicochemical and structural properties that respond differently to environmental stimuli. 100 29–30 May 2025, Ljubljana, Slovenia These two factors can be analysed both individually and in relation to each other. In addition, a third critical com-ponent — the external environment — must also be considered, as it significantly influences bacterial adhesion through variables such as humidity, temperature and the possible presence of bioactive compounds. Given these complex relationships, it is not surprising that the results of the various studies are often contradicto-ry, as we pointed out in our earlier literature review (Čuk, 2024). From the perspective of a young researcher, this can be particularly challenging, as enthusiasm for new findings is interrupted by a sudden shift in understanding when one encounters new literature. This requires an adaptive approach, similar to the behaviour of bacteria themselves: constantly adapting to new information and external influences. Interest in bacterial adhesion to textiles has increased 45-fold over the last two decades, judging by the number of published studies on this topic (Web of Science search on 22 January 2025 using the keywords »bacterial adhesion or bacterial adherence« and »textile or fabric« for the years 2003–2023). This result illustrates both the complexity and the potential of the top-ic. The challenges are great, but they also offer opportunities for innovative, interdisciplinary and holistic research. After identifying a relevant research gap, the individual properties of the selected textiles were analysed, followed by an investigation of bacterial adhesion to their surfaces. Among the textile factors, the chemical composition plays a key role in determining the properties of the textile material and consequently the extent of bacterial adhe-sion. In particular, the chemical structure or the presence or absence of certain functional groups in the chemical formula of the fibre-forming polymers determine the hydrophilicity or hydrophobicity of the textiles themselves. However, a review of existing studies shows contradictory conclusions as to whether hydrophilic or hydrophobic textile fibres are more susceptible to bacterial adhesion (Čuk, 2024). The aim of this study is therefore to contribute to solving the above dilemma (i). In addition to providing valuable insights for researchers and other stakeholders, a secondary objective was to illustrate the theoretical research process for students using a real-life example (ii). However, it should be emphasised that this study is only one part of a larger research framework aimed at gaining a comprehensive and interdisciplinary understanding of bac-terial adhesion to textiles. The full scope of our team’s interdisciplinary research approach is illustrated in Figure 1. Figure 1: Our interdisciplinary research journey of a potential topic 2. EXPERIMENTAL WORK 2.1 Tested materials and included test organisms Two different woven fabrics in satin weave were produced on the Minifaber weaving machine with electronic jacquard T.I.S. (Minifaber Spa, Italy) at the Faculty of Natural Sciences and Engineering of the University of Ljubl-jana (Ljubljana, Slovenia). Warp cotton with the sequence (1 black: 1 white), fineness 2 x 8 tex and with 100% optically bleached white warp threads was used. Cotton (60 tex) and polyester (25 tex) were used as weft threads. The warp density for both samples was 40 threads/cm, the weft density 18 threads/cm. 101 29–30 May 2025, Ljubljana, Slovenia The test organism Escherichia coli ATCC 35 218 (E. coli) was obtained from the collection of the Faculty of Health Sciences of the University of Ljubljana. The cryopreserved bacterial strain was inoculated on Tryptic Soy Agar and incubated at 37 °C for 24 hours to obtain initial cells. The woven fabric samples, medium and solution were autoclaved before the experiment. 2.2 Methods used Fourier Transform Infrared Spectroscopy (FTIR) was performed to confirm the hydrophilicity or hydrophobicity of cotton and polyester woven fabrics. The thickness of fabrics was measured according to the SIST EN ISO 5084 standard, while the mass per unit area was measured according to SIST EN 12127 as two of the basic physical textile parameters. Finally, bacterial adhesion was analysed according to the SIST EN ISO 20743:2007 standard, Figure 2. In this method, the bacterial strains of E. coli were first incubated overnight. After this, the test solution was prepared at a concentration of 0.5 according to McFarland. Then 19.6 ml of the 0.9 % saline solution was mixed with 0.4 ml of prepared test suspension. 0.2 ml of the mixed solution was added to the individual cotton and polyester sample and afterwards incubated for 24 hours at 37°C. After incubation, the inoculated textile samples were placed in vials which contained neutralisation solution SCDLP (7 g polysorbate 80, 3 g lecithin, 5 g nutrient broth/1000 ml 0.9% saline solution). Vials containing textile samples and neutralisation solution SCDLP were then shaken for 5 minutes at 10.000 rpm. This was followed by serial dilution, solid media inoculation and incubation (24 hours, 37°C). Figure 2: Protocol of the standard SIST EN ISO 20743:2007 3. RESULTS Figure 3A shows the FTIR spectra of the studied cotton and polyester fabrics. The characteristic absorption bands of cellulose in the fingerprint region (1500–800 cm-¹), which correspond to the C-O-C, C-H and C-O vibrations, can be clearly recognised in the spectrum of the cotton fabric. In addition, a broad absorption band in the range of 3700–3000 cm-1 is attributed to the O-H stretching vibrations of adsorbed water, while the absorption band at 1640 cm-1 corresponds to the bending vibrations of the –OH groups of adsorbed water (Socrates, 2001). In contrast, the FTIR spectrum of the polyester fabric shows a strong and distinct absorption band at 1720 cm 1, which corresponds to the C=O stretching vibrations of the ester carbonyl group. It is accompanied by C-O and C-O-C vibrations in the range of 1090–1375 cm-1 as well as C-H and C-C stretching vibrations of the benzene ring in the range of 790–850 cm-1. A weaker band at 3430 cm-¹ corresponds to the intermolecular O-H bond. It is note-worthy that the O-H stretching band in polyester is significantly weaker than the broad and intense O-H adsorption at ~3400 cm-1 observed in cotton (Socrates, 2021). This clear difference in spectral characteristics emphasises the contrast between the hydrophilic nature of cotton and the hydrophobic character of polyester. Indeed, the abundance of hydroxyl groups (-OH) in cotton enables strong hydrogen bonding with water and makes it very absorbent. In contrast, the dominance of ester bonds (-COO-) and aromatic rings in polyester leads to a rather non-polar, hydrophobic surface that limits water absorp-tion. 102 29–30 May 2025, Ljubljana, Slovenia Figure 3B shows the physical parameters of the studied woven samples. The thickness and mass per unit area were lower for polyester fabric compared to cotton, which is both reasonable and expected. This difference is due to the finer polyester yarn in the weft (25 tex) and the coarser cotton yarn (60 tex). With constant warp and weft yarn density in the weaving process, the polyester fabric had 44% less mass per unit area than the cotton fabric. Figure 3: A. FTIR spectra analyses; B. Schematic representation of the values of the investigated physical textile parameters The results of the bacterial adhesion tests show that the test organism E. coli adhered more strongly to the poly-ester sample (7.070.22 log CFU/ml) than to cotton (4.910.80 log CFU/ml), Figure 4. This result agrees with the study by Koziarz, which concludes that hydrophobic textile materials have a greater affinity for E. coli 3300 than hydrophilic materials (Koziarz, 1998). The stronger adhesion to polyester can be attributed to the hydrophobic surface of the material, which enables stronger binding of the bacteria due to van der Waals forces and a limited interaction with moisture. This observation is in line with the results of Møllebjerg et al. who found that more bac-terial cells ( S. hominis DSM 20328, S. epidermidis DSM 20044, M. luteus DSM 20030 and C. jeikeium DSM 7171) adhere to polyester than to hydrophilic cotton (Møllebjerg, 2021). Figure 4: E. coli adhesion to hydrophilic cotton and hydrophobic polyester fabric 4. CONCLUSIONS In this study, E. coli (a common member of the human microbiota) was found to adhere more strongly to the hy-drophobic polyester sample than to the hydrophilic cotton sample, highlighting the role of material properties in bacterial adhesion. Given the complexity of bacterial adhesion to textiles, an interdisciplinary approach is essen-tial to gain a more comprehensive understanding of the phenomenon 103 29–30 May 2025, Ljubljana, Slovenia 5. ADDITIONAL Acknowledgements: The authors would like to thank Tech. Assist. Tomaž Stergar for his guidance in the labo-ratory during material testing and Assist. Alenka More for the preparation – laser cutting – of the textile samples. Funding: This research was cofounded by the Slovenian Research and Innovation Agency (Programme P2-0213 Textiles and Ecology, Infrastructural Centre RIC UL-NTF and a Grant for the doctoral student N.Č.) 6. REFERENCES Basu, A., Basu, S., Bandyopadhyay, S. and Chowdhury, R. 2015. “Optimization of evaporative extraction of natural emulsifier cum surfactant from Sapindus mukorossi—Characterization and cost analysis.” Industrial Crops and Products (77): 920–931. Caenn, R., Darley, H. C. H. and Gray, G. R. 2011. Composition and Properties of Drilling and Completion Fluids. Waltham: Gulf Professional Publishing. Čuk, N., Simončič, B., Fink, R. and Tomšič, B. 2024 “Bacterial Adhesion to Natural and Synthetic Fibre-Forming Polymers: Influence of Material Properties.” Polymers (16): 1−30. Missirlis, Y. F. and Katsikogianni, M. 2007. “Theoretical and Experimental Approaches of Bacteria-Biomaterial Interactions.” Materwiss Werksttech (38): 983–994. Čuk, N., Simončič, B., Fink, R. and Tomšič, B. 2024. “Unveiling the impact of cotton surface free energy on bacterial adhesion capacity.” In Book of proceedings: magic world of textiles: 11th International Textile, Clothing & Design Conference [also] ITC&DC, October 6th to October 9th, 2024, Dubrovnik, Croatia., edited by Zvonko Dragčević, Anica Hursa Šajatović and Ivana Špelić, 39−44. Zagreb: University of Zagreb, Faculty of Textile Technology. Koziarz, J. 1998. “Adhesion and immobilization of bacteria on hydrophobic cloths.” Master’s Thesis, Ottawa-Carleton Institute of Biology, Ottawa. Møllebjerg, A., Palmén, L.G., Gori, K., Meyer, R. L. 2021. “The Bacterial Life Cycle in Textiles is Governed by Fiber Hydrophobicity.” Microbiol Spectr 9 (2). Nielsen, C. K., Kjems, J., Mygind, Snabe, T. and Meyer R. L. 2016. ”Effects of Tween 80 on Growth and Biofilm Formation in Laboratory Media”. Frontiers in Microbiology (7): 1–10. Socrates G., Infrared Characteristic Group Frequencies. Tables and Charts, John Wiley & Sons Ltd, 2001. https://doi.org/10.1016/0003-2670(94)80274-2. Żenkiewicz, M. 2007. “Methods for the calculation of surface free energy of solids.” Journal of Achievements of Materials and Manufacturing Engineering 24 (1): 137–145. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): University of Ljubljana University of Ljubljana University of Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences Brigita Tomšič Nina Čuk Klara Kostajnšek Faculty of Natural Sciences and Engineering and Engineering and Engineering Aškerčeva cesta 12 Aškerčeva cesta 12 Aškerčeva cesta 12 1000, Ljubljana 1000, Ljubljana 1000, Ljubljana nina.cuk@ntf.uni-lj.si klara.kostajnšek@ntf.uni-lj.si brigita.tomsic@ntf.uni-lj.si Barbara Simončič Matejka Bizjak University of Ljubljana University of Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering Aškerčeva cesta 12 Aškerčeva cesta 12 1000, Ljubljana 1000, Ljubljana barbara.simoncic@ntf.uni-lj.si matejka.bizjak@ntf.uni-lj.si Rok Fink University of Ljubljana Faculty of Health Sciences Zdravstvena pot 5 1000, Ljubljana rok.fink@zf.uni-lj.si 104 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION ENVIRONMENTALLY FRIENDLY TiO /GRAPHITIC CARBON NITRIDE 2 NANOCOMPOSITE FOR MULTIFUNCTIONAL COTTON FABRIC Dominika Glažar1, Brigita Tomšič1, Danaja Štular2, Ivan Jerman2, 3 Raghuraj S. Chouhan and Barbara Simončič 1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2 National Institute of Chemistry, Slovenia 3 Jožef Stefan Institute, Slovenia Abstract: This study aims at the synthesis of environmentally friendly TiO /graphitic carbon nitride (gCN) nano-2 composite used for the functionalisation of cotton (CO) to achieve multifunctional UV protection and photocatalytic dye degradation. The CO modified with TiO /gCN nanocomposite was prepared by the synthesis of TiO using 2 2 an environmentally friendly precipitating agent (acetic acid) in the presence of CO and pre-synthesised gCN at room temperature. The UV protection factor of CO modified with TiO /gCN was significantly higher than that of 2 CO modified with TiO or gCN alone. In addition, the CO modified with TiO /gCN showed superior degradation 2 2 efficiency of the Rhodamine B dye, which was attributed to the effective reduction of the band gap energy and the lower recombination of charge carriers in the semiconductor nanocomposite. Keywords: Textile functionalization, Titanium dioxide (TiO ), Graphitic carbon nitride (gCN), UV protection, Pho-2 tocatalytic activity. 1. INTRODUCTION Multifunctional technical textiles are categorised as advanced high-tech textile materials that are used in many different industries as protective, medical, electronic, bio-, agro-, geo- and aerotextiles as well as sports textiles. They are characterised by the simultaneous expression of multiple functional properties, such as photocatalytic activity, self-cleaning activity and protection against ultraviolet (UV) radiation (Hassan, 2019). Their production is based on the incorporation of chemical finishing agents and other active components with different structures, which change the chemical and morphological properties of the textile fibres on the surface and/or in the mass. A major technological breakthrough in their development was the integration of nanotechnology, which made it possible to incorporate various nanomaterials into textile fibres. This made it possible to achieve special textile properties that could not be obtained by conventional chemical modification processes (Hassan, 2019). However, many of the current nanotechnology processes for the chemical modification of textiles are not based on the prin-ciples of environmentally friendly development. Among the various approaches to chemical surface modification of textile fibres, nanocomposite coatings conta-ining metal oxides are widely used, with titanium dioxide (TiO ) being the most commonly used material. TiO is 2 2 known as the „golden“ photocatalyst and is favoured for its semiconducting properties, which give textiles photo-catalytic self-cleaning, antimicrobial activity, UV protection and improved thermal stability (Rashid, 2021). Photo-catalytic activity is directly induced by exposure to UV light, which excites electrons from the valence band (VB) to the conduction band (CB), creating holes in the VB. Both electrons and holes are charge carriers that engage in redox reactions with oxygen and water on the TiO surface, generating highly reactive oxygen species (ROS). 2 The ROS can then interact with adsorbed pollutants, such as dyes in wastewater, leading to their degradation into carbon dioxide and water (Rashid, 2021; Nur, 2022). Despite its advantages, the use of TiO in textile finishing is 2 limited due to its wide band gap (E ), which restricts its activity to UV light. g To improve the photocatalytic performance of TiO in the presence of visible light, various approaches are being 2 pursued, such as doping with noble metals or preparation of semiconductor nanocomposites using narrow band gap semiconductors (Rashid, 2021). A promising material in this regard is graphitic carbon nitride (gCN), a novel, sustainable carbon-based photocatalyst. gCN has unique optical and electronic properties, high physico-chemical 105 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia and thermal stability, excellent corrosion resistance, and low-cost fabrication. Due to its narrow band gap, it is photocatalytically active under visible light up to wavelength of around 460 nm (Vasiljević, 2021). When illumina- VB edge, reactive oxygen species (ROS) are only generated by electrons, while the photo-generated holes are 2021). When illuminated, the electrons in the VB are excited to CB, leaving holes in the VB. However, due to narrow band gap, it is photocatalytically active under visible light up to wavelength of around 460 nm (Vasiljevi ć , directly involved in the degradation of organic pollutants (Su, 2017). ted, the electrons in the VB are excited to CB, leaving holes in the VB. However, due to the energy levels of the narrow band gap, it is photocatalytically active under visible light up to wavelength of around 460 nm (Vasiljevi ć , potential to photodegrade Rhodamine B (RhB) dye in aqueous solution. It is hypothesized that the incorporation The aim of this research is to in-situ synthesize TiO2/gCN nanocomposite for the chemical modification of photo-generated holes are directly involved in the degradation of organic pollutants (Su, 2017). cotton fabric (CO). The research focuses on investigating the UV protection properties of the modified CO as The aim of this research is to in-situ synthesize TiO 2 /gCN nanocomposite for the chemical modification of of TiO /gCN nanocomposite into the CO fabric would provide improved UV protection and effective decolorization well as its potential to photodegrade Rhodamine B (RhB) dye in aqueous solution. It is hypothesized that the cotton fabric (CO). The research focuses on investigating the UV protection properties of the modified CO as 2 of the RhB dye solution. incorporation of TiO The aim of this research is to in-situ synthesize TiO photo-generated holes are directly involved in the degradation of organic pollutants (Su, 2017). /gCN nanocomposite for the chemical modification of cotton the energy levels of the VB edge, reactive oxygen species (ROS) are only generated by electrons, while the 2 fabric (CO). The research focuses on investigating the UV protection properties of the modified CO as well as its the energy levels of the VB edge, reactive oxygen species (ROS) are only generated by electrons, while the 2021). When illuminated, the electrons in the VB are excited to CB, leaving holes in the VB. However, due to well as its potential to photodegrade Rhodamine B (RhB) dye in aqueous solution. It is hypothesized that the 2 /gCN nanocomposite into the CO fabric would provide improved UV protection and effective decolorization of the RhB dye solution. incorporation of TiO 2 /gCN nanocomposite into the CO fabric would provide improved UV protection and 2. EXPERIMENTAL effective decolorization of the RhB dye solution. 2. EXPERIMENTAL 2.1 Materials 2. EXPERIMENTAL Chemically bleached 100% cotton fabric (CO) with a mass per unit area of 120 g/m 2.1 Materials 2 (Tekstina d.o.o., Ajdovščina, 99% concentration) and acetic acid (AA; 99% concentration), all products from Sigma Aldrich (USA), were used Ajdovščina , Slovenia) was used for this study. Titanium(IV) isopropoxide(TTIP; ≥ 97.8% concentration), Chemically bleached 100% cotton fabric (CO) with a mass per unit area of 120 g/m 2 (Tekstina d.o.o., to prepare TiO isopropanol (iPrOH; nanoparticles (NPs). The layered particles of graphitic carbon nitride (gCN) were synthesized at ≥ 99% concentration) and acetic acid (AA; 99% concentration), all products from Sigma Ajdovščina Slovenia) was used for this study. Titanium(IV) isopropoxide(TTIP; ≥ 97.8% concentration), isopropanol (iPrOH; ≥ 2.1 Materials Chemically bleached 100% cotton fabric (CO) with a mass per unit area of 120 g/m 2 (Tekstina d.o.o., the National Institute of Chemistry, Slovenia – Department of Materials Chemistry. Rhodamine B (RhB; Sigma Aldrich (USA), were used to prepare TiO 2 nanoparticles (NPs). The layered particles of graphitic carbon nitride isopropanol (iPrOH; ≥ 99% concentration) and acetic acid (AA; 99% concentration), all products from Sigma (gCN) were synthesized at the National Institute of Chemistry, Slovenia – Department of Materials Chemistry. , Slovenia) was used for this study. Titanium(IV) isopropoxide(TTIP; 2≥ 97.8% concentration), 2.2 Preparation of chemically modified cotton samples Rhodamine B (RhB; Sigma Aldrich, USA) was used as dye. (gCN) were synthesized at the National Institute of Chemistry, Slovenia – Department of Materials Chemistry. Aldrich, USA) was used as dye. Aldrich (USA), were used to prepare TiO2 nanoparticles (NPs). The layered particles of graphitic carbon nitride The following method was used to produce chemically modified CO with a two-component composite TiO 2.2 Preparation of chemically modified cotton samples Rhodamine B (RhB; Sigma Aldrich, USA) was used as dye. 2/gCN sonicated for 2 hours. A solution containing 12 g TTIP, 68 g iPrOH and 20 g AA was then added to the beaker and (sample CO(TiO 2 /gCN)). In a beaker, 2 g of the previously synthesized gCN was dissolved in 98 g iPrOH and The following method was used to produce chemically modified CO with a two-component composite TiO 2 /gCN the mixture was placed on a magnetic stirrer with continued sonication. CO was added while stirring, followed by sonicated for 2 hours. A solution containing 12 g TTIP, 68 g iPrOH and 20 g AA was then added to the beaker (sample CO(TiO (sample CO(TiO 2.2 Preparation of chemically modified cotton samples The following method was used to produce chemically modified CO with a two-component composite TiO /gCN)). In a beaker, 2 g of the previously synthesized gCN was dissolved in 98 g iPrOH and 2 2 /gCN dropwise addition of 200 g distilled water. The solution was then sonicated and stirred for a further 2 hours at room and the mixture was placed on a magnetic stirrer with continued sonication. CO was added while stirring, sonicated for 2 hours. A solution containing 12 g TTIP, 68 g iPrOH and 20 g AA was then added to the beaker followed by dropwise addition of 200 g distilled water. The solution was then sonicated and stirred for a further 2 /gCN)). In a beaker, 2 g of the previously synthesized gCN was dissolved in 98 g iPrOH and synthesis. After synthesis, the samples 2 hours at room temperature. After completion of sonication, magnetic stirring was continued for 15 minutes were squeezed with a 95 ± 2% wet pick-up, air dried and cured at 150 °C followed by dropwise addition of 200 g distilled water. The solution was then sonicated and stirred for a further to ensure complete synthesis. After synthesis, the samples were squeezed with a 95 ± 2% wet temperature. After completion of sonication, magnetic stirring was continued for 15 minutes to ensure complete and the mixture was placed on a magnetic stirrer with continued sonication. CO was added while stirring, tions to produce CO(gCN) and CO(TiO ) samples, respectively. 2 were dried and cured at 150 °C for 5 minutes. The functionalized CO samples were then rinsed three times with 2 applied to CO under identical conditions to produce CO(gCN) and CO(TiO 2 ) samples, respectively. distilled water for 1 minute each time and dried in air. For comparison, single-component gCN and TiO 2 were applied to CO under identical conditions to produce CO(gCN) and CO(TiO 2 ) samples, respectively. 2.3 Characterization 2.3 Characterization time and dried in air. For comparison, single-component gCN and TiO dried and cured at 150 °C for 5 minutes. The functionalized CO samples were then rinsed three times with to ensure complete synthesis. After synthesis, the samples were squeezed with a 95 ± 2% wet were applied to CO under identical condi-2 pick-up, air distilled water for 1 minute each time and dried in air. For comparison, single-component gCN and TiO for 5 minutes. The functionalized CO samples were then rinsed three times with distilled water for 1 minute each pick-up, air 2 hours at room temperature. After completion of sonication, magnetic stirring was continued for 15 minutes The Ti concentration in CO(TiO 2.3 Characterization ) and CO(TiO /gCN) samples was determined using inductively coupled plasma The Ti concentration in CO(TiO 2 2 ) and CO(TiO 2 2 /gCN) samples was determined using inductively coupled The transmission spectra of the CO samples were recorded in a wavelength ( plasma mass spectrometry (ICP-MS). λ) range 200–800 nm using a The transmission spectra of the CO samples were recorded in a wavelength ( λ ) range 200–800 nm using a Lambda 800+ UV/Vis spectrophotometer (Perkin Elmer, Great Britain). A minimum thirteen measurements were Lambda 800+ UV/Vis spectrophotometer (Perkin Elmer, Great Britain). A minimum thirteen measurements mass spectrometry (ICP-MS). plasma mass spectrometry (ICP-MS). The Ti concentration in CO(TiO 2 ) and CO(TiO2/gCN) samples was determined using inductively coupled performed for each sample and the average value of transmittance (T) at each The transmission spectra of the CO samples were recorded in a wavelength (λ) range 200–800 nm using a λ was calculated. The average were performed for each sample and the average value of transmittance (T) at each λ was calculated. The Lambda 800+ UV/Vis spectrophotometer (Perkin Elmer, Great Britain). A minimum thirteen measurements transmission spectra were converted into absorption spectra using the following equation: average transmission spectra were converted into absorption spectra using the following equation: were performed for each sample and the average value of transmittance (T) at each λ was calculated. The average transmission spectra were converted into absorption spectra using the following equation: A = − log T (1) where A represents absorbance. From the absorption spectra, the optical bang gap energies (E where A represents absorbance. From the absorption spectra, the optical bang gap energies (E A = −log T (1) g ) of the chemically modified CO samples were determined using Tauc relation (Karkare, 2015): ) of the chemically where A represents absorbance. From the absorption spectra, the optical bang gap energies (E g g ) of the modified CO samples were determined using Tauc relation (Karkare, 2015): chemically modified CO samples were determined using Tauc relation (Karkare, 2015): 2 ( 𝛼𝛼𝛼𝛼 h 𝜈𝜈𝜈𝜈 ) = 𝐾𝐾𝐾𝐾 (h 𝑣𝑣𝑣𝑣 – E g ) (2) where where ( 2 (2) 𝛼𝛼𝛼𝛼 h 𝜈𝜈𝜈𝜈 ) = 𝐾𝐾𝐾𝐾 (h 𝑣𝑣𝑣𝑣 – E g ) is the energy-dependent absorption coefficient, equal to 2.303 x α A, h is Planck constant, ν is the frequency of the radiation, and K is a constant. According to Planck's radiation law, the energy ( E ) of where α is the energy-dependent absorption coefficient, equal to 2.303 x A, h is Planck constant, ν is radiation is equal to: α is the energy-dependent absorption coefficient, equal to 2.303 x A, h is Planck constant, ν is the frequen - the frequency of the radiation, and K is a constant. According to Planck's radiation law, the energy ( E ) of 1240 cy of the radiation, and K is a constant. radiation is equal to: 𝐸𝐸𝐸𝐸 = h 𝑣𝑣𝑣𝑣 = (3) 𝜆𝜆𝜆𝜆 1240 𝐸𝐸𝐸𝐸 = h 𝑣𝑣𝑣𝑣 = (3) 𝜆𝜆𝜆𝜆 2106 2 A = −log T (1) where A represents absorbance. From the absorption spectra, the optical bang gap energies (Eg) of the chemically modified CO samples were determined using Tauc relation (Karkare, 2015): 29–30 May 2025, Ljubljana, Slovenia ( 2 (2) 𝛼𝛼𝛼𝛼 h 𝜈𝜈𝜈𝜈 ) = 𝐾𝐾𝐾𝐾 (h 𝑣𝑣𝑣𝑣 – E g ) According to Planck‘s radiation law, the energy ( the frequency of the radiation, and E) of radiation is equal to: K is a constant. According to Planck's radiation law, the energy (E) of 29–30 May 2025, Ljubljana, Slovenia where α is the energy-dependent absorption coefficient, equal to 2.303 x A, h is Planck constant, ν is radiation is equal to: 𝐸𝐸𝐸𝐸 1240 = h 𝑣𝑣𝑣𝑣 = (3) 𝜆𝜆𝜆𝜆 The values of E are obtained through extrapolation to α = 0 (Karkare, 2015). g 29–30 May 2025, Ljubljana, Slovenia The values of E g are obtained through extrapolation to α = 0 (Karkare, 2015). The UV protection factor (UPF) of CO samples was determined according to the Standard EN 13758-1:2001. The UV protection factor (UPF) of CO samples was determined according to the Standard EN 13758-1:2001. 2 Transmission was calculated at UVA from 315 to 400 nm and UVB from 280 to 315 nm regions. The UPF was Transmission was calculated at UVA from 315 to 400 nm and UVB from 280 to 315 nm regions. The UPF was calculated using the following equation (SIST EN 13758-1:2002): calculated using the following equation (SIST EN 13758-1:2002): where E The values of Eg are obtained through extrapolation to 400α = 0 (Karkare, 2015). ∑ E ( 𝜆𝜆𝜆𝜆 ) 290 𝑥𝑥𝑥𝑥𝑥𝑥𝑥𝑥 ( 𝜆𝜆𝜆𝜆 ) 𝑥𝑥𝑥𝑥𝑥𝑥𝑥𝑥 ( 𝜆𝜆𝜆𝜆 ) UPF = The UV protection factor (UPF) of CO samples was determined according to the Standard EN 13758-1:2001. 400 (4) ∑ E ( 𝜆𝜆𝜆𝜆 ) 𝑥𝑥𝑥𝑥𝑥𝑥𝑥𝑥 ( 𝜆𝜆𝜆𝜆 ) 290 𝑥𝑥𝑥𝑥𝑥 ( 𝜆𝜆𝜆𝜆 ) 𝑥𝑥𝑥𝑥𝑥𝑥𝑥𝑥 ( 𝜆𝜆𝜆𝜆 ) Transmission was calculated at UVA from 315 to 400 nm and UVB from 280 to 315 nm regions. The UPF was calculated using the following equation (SIST EN 13758-1:2002): where E ( λ) represents the solar spectral irradiance , ε(λ) represents the relative erythemal effectiveness, Δ(λ) (λ) represents the solar spectral irradiance , ε(λ) represents the relative erythemal effectiveness, Δ(λ) re-represents the wavelength interval, and T ( λ) is the spectral transmittance at the λ . presents the wavelength interval, and T (λ) is the spectral transmittance at the 400 ∑ λ . The UPF rating and protection categories were determined based on UPF values, following the Australian/ E ( 𝜆𝜆𝜆𝜆 ) 290 𝑥𝑥𝑥𝑥𝑥𝑥𝑥𝑥 ( 𝜆𝜆𝜆𝜆 ) 𝑥𝑥𝑥𝑥𝑥𝑥𝑥𝑥 ( 𝜆𝜆𝜆𝜆 ) UPF = 400 (4) New Zealand Standard for Sun-Protective Clothing— Evaluation and Classification (AS/NZS 4399, 2020). UPF ∑ E ( 𝜆𝜆𝜆𝜆 ) 𝑥𝑥𝑥𝑥𝑥𝑥𝑥𝑥 ( 𝜆𝜆𝜆𝜆 ) 290 𝑥𝑥𝑥𝑥𝑥 ( 𝜆𝜆𝜆𝜆 ) 𝑥𝑥𝑥𝑥𝑥𝑥𝑥𝑥 ( 𝜆𝜆𝜆𝜆 ) The UPF rating and protection categories were determined based on UPF values, following the Australian/ New values of 15 correspond to the »minimum protection« category, values of 30 to the »good protection« category, Zealand Standard for Sun-Protective Clothing— Evaluation and Classification (AS/NZS 4399, 2020). UPF values where E ( λ) represents the solar spectral irradiance , ε(λ) represents the relative erythemal effectiveness, Δ(λ) and values of 50 to the »excellent protection« category. of 15 correspond to the »minimum protection« category, values of 30 to the »good protection« category, and va-represents the wavelength interval, and T ( λ) is the spectral transmittance at the λ . lues of 50 to the »excellent protection« category. The UPF rating and protection categories were determined based on UPF values, following the Australian/ The photocatalytic activity of the samples was assessed by evaluating the degradation of the aqueous 0,02 New Zealand Standard for Sun-Protective Clothing— Evaluation and Classification (AS/NZS 4399, 2020). UPF mM RhB solution under daylight using Xenotest Alpha instrument equipped with a visible xenon arc lamp values of 15 correspond to the »minimum protection« category, values of 30 to the »good protection« category, (radiation settings, 0.8–2.5 kVA, and extended radiation range, 300–400 nm). The CO samples (0.8 cm x 4.1 and values of 50 to the »excellent protection« category. The photocatalytic activity of the samples was assessed by evaluating the degradation of the aqueous 0,02 mM cm) were immersed in 3 ml of a RhB solution in cuvettes, that were initially kept in the dark for 30 minutes to RhB solution under daylight using Xenotest Alpha instrument equipped with a visible xenon arc lamp (radiation achieve adsorption-desorption equilibrium. The samples were then irradiated for a total of 180 minutes, with The photocatalytic activity of the samples was assessed by evaluating the degradation of the aqueous 0,02 settings, 0.8–2.5 kVA, and extended radiation range, 300–400 nm). The CO samples (0.8 cm x 4.1 cm) were measurements taken at 30 minute intervals. At each interval, the A of the RhB solution was measured at the mM RhB solution under daylight using Xenotest Alpha instrument equipped with a visible xenon arc lamp immersed in 3 ml of a RhB solution in cuvettes, that were initially kept in the dark for 30 minutes to achieve ad maximum absorption wavelength ( λ max = 552.93 nm). The corresponding dye concentration in the solution was -(radiation settings, 0.8–2.5 kVA, and extended radiation range, 300–400 nm). The CO samples (0.8 cm x 4.1 sorption-desorption equilibrium. The samples were then irradiated for a total of 180 minutes, with measurements determined using previously established calibration curves. cm) were immersed in 3 ml of a RhB solution in cuvettes, that were initially kept in the dark for 30 minutes to taken at 30 minute intervals. At each interval, the A of the RhB solution was measured at the maximum absorption The photocatalytic degradation of RhB dye was quantified by calculating the concentration ratio of C t to C 0 , achieve adsorption-desorption equilibrium. The samples were then irradiated for a total of 180 minutes, with wavelength (λ where C t represents the dye concentration at a given time of irradiation and = 552.93 nm). The corresponding dye concentration in the solution was determined using pre C 0 represents the initial dye -measurements taken at 30 minute intervals. At each interval, the A of the RhB solution was measured at the max viously established calibration curves. concentration after the adsorption-desorption equilibrium. Based on these results, the apparent rate constant maximum absorption wavelength ( λ (K max = 552.93 nm). The corresponding dye concentration in the solution was app ) of the photocatalytic reaction was determined as a measure of the dyes photocatalytic degradation determined using previously established calibration curves. The photocatalytic degradation of RhB dye was quantified by calculating the concentration ratio of efficiency, assuming pseudo-first-order kinetic behaviour, as described by the following equation (Shafique, C to C , where t 0 The photocatalytic degradation of RhB dye was quantified by calculating the concentration ratio of C C represents the dye concentration at a given time of irradiation and 2022): C represents the initial dye concentration t to C 0 , t 0 where C after the adsorption-desorption equilibrium. Based on these results, the apparent rate constant (K t represents the dye concentration at a given time of irradiation and 𝐶𝐶𝐶𝐶 t C 0 represents the initial dye ) of the pho-ln = − K concentration after the adsorption-desorption equilibrium. Based on these results, the apparent rate constant app app t (5) tocatalytic reaction was determined as a measure of the dyes photocatalytic degradation efficiency, assuming 𝐶𝐶𝐶𝐶 0 (K app ) of the photocatalytic reaction was determined as a measure of the dyes photocatalytic degradation pseudo-first-order kinetic behaviour, as described by the following equation (Shafique, 2022): where t is the illumination time. efficiency, assuming pseudo-first-order kinetic behaviour, as described by the following equation (Shafique, 2022): 3. RESULTS WITH DISCUSSION 𝐶𝐶𝐶𝐶 app ln 𝐶𝐶𝐶𝐶t = −K t (5) 0 where t is the illumination time. The results of the ICP-MS analysis showed that the presence of gCN increased the amount of Ti in the where t is the illumination time. nanocomposite from 4900 mg/kg for the CO(TiO2) sample to 5700 mg/kg for the CO(TiO2/gCN) sample. The results of the ICP-MS analysis showed that the presence of gCN increased the amount of Ti in the nanocom The results of the ICP-MS analysis showed that the presence of gCN increased the amount of Ti in the incorporation of TiO 2 to the CO(TiO 2 ) sample led to a significant increase in UV absorption especially at -nanocomposite from 4900 mg/kg for the CO(TiO wavelengths below 350 nm. However, when both TiO 2 ) sample to 5700 mg/kg for the CO(TiO 2 /gCN) sample. posite from 4900 mg/kg for the CO(TiO ) sample to 5700 mg/kg for the CO(TiO 2 and gCN were combined in the CO(TiO /gCN) sample. 2 /gCN) sample, The absorption spectra of the studied samples are presented in Figure 1a. The CO(UN) sample exhibited the 2 2 a significant increase in absorbance was observed in both the UV and visible ranges, indicating a compatibility lowest light absorption across the range of 200 nm to 800 nm. The presence of gCN in CO(gCN) sample led The absorption spectra of the studied samples are presented in Figure 1a. The CO(UN) sample exhibited the of both components in the nanocomposite. to a slight increase in the absorption of UV and visible light, especially at wavelengths below 450 nm. The lowest light absorption across the range of 200 nm to 800 nm. The presence of gCN in CO(gCN) sample led to a 3. lowest light absorption across the range of 200 nm to 800 nm. The presence of gCN in CO(gCN) sample led 3. RESULTS WITH DISCUSSION RESULTS WITH DISCUSSION to a slight increase in the absorption of UV and visible light, especially at wavelengths below 450 nm. The The absorption spectra of the studied samples are presented in Figure 1a. The CO(UN) sample exhibited the slight increase in the absorption of UV and visible light, especially at wavelengths below 450 nm. The incorpora incorporation of TiO The Tauc plots (Figure 1 b) obtained from the absorption spectra show that the incorporation of both TiO2 and gCN into a nanocomposite (CO(TiO 2 to the CO(TiO 2 2 ) sample led to a significant increase in UV absorption especially at /gCN) sample) resulted to a reduction in the E in absorbance was observed in both the UV and visible ranges, indicating a compatibility of both components in 3.5 eV, while that of gCN in CO(gCN) sample was 2.9 eV, however, for the CO(TiO and gCN were combined in the CO(TiO /gCN) sample, a significant increase 2 /gCN) sample, the E g of both components in the nanocomposite. 2 2 values are 3.3 and 2.7 eV, respectively. These results indicate that the bathochromic shift of light absorbance The Tauc plots (Figure 1 b) obtained from the absorption spectra show that the incorporation of both TiO was achieved in the semiconductor nanocomposite. 2 and the nanocomposite. gCN into a nanocomposite (CO(TiO 2 /gCN) sample) resulted to a reduction in the E g compared to gCN (CO(gCN) sample) or TiO 350 nm. However, when both TiO a significant increase in absorbance was observed in both the UV and visible ranges, indicating a compatibility ) sample led to a significant increase in UV absorption especially at wavelengths below 2 (CO(TiO 2 ) sample) alone. Specifically, the E g of TiO 2 in the CO(TiO 2 ) sample was 2 2 tion of TiO wavelengths below 350 nm. However, when both TiO g compared to gCN - (CO(gCN) sample) or TiO 2 and gCN were combined in the CO(TiO2/gCN) sample, to the CO(TiO 2 2 g 2 2 (CO(TiO ) sample) alone. Specifically, the E of TiO in the CO(TiO) sample was 3.5 eV, while that of gCN in CO(gCN) sample was 2.9 eV, however, for the CO(TiO2/gCN) sample, the Eg values are 3.3 and 2.7 eV, respectively. These results indicate that the bathochromic shift of light absorbance was achieved in the semiconductor nanocomposite. 107 29–30 May 2025, Ljubljana, Slovenia The Tauc plots (Figure 1 b) obtained from the absorption spectra show that the incorporation of both TiO and 2 gCN into a nanocomposite (CO(TiO /gCN) sample) resulted to a reduction in the E compared to gCN (CO(gCN) 2 g sample) or TiO (CO(TiO ) sample) alone. Specifically, the E of TiO in the CO(TiO ) sample was 3.5 eV, while 2 2 g 2 2 that of gCN in CO(gCN) sample was 2.9 eV, however, for the CO(TiO /gCN) sample, the E values are 3.3 and 2 g 2.7 eV, respectively. These results indicate that the bathochromic shift of light absorbance was achieved in the semiconductor nanocomposite. Figure 1: Absorbance (A) of untreated and chemically modified samples (a) and Tauc plots of chemically modified samples (black lines determine the E values on x exis) (b) g The UV protection properties (Figure 2) of the chemically modified CO samples were determined using the tran-smission spectra in the 280–400 nm range. The results show that CO(UN) sample exhibits the highest light tran-smittance in the 280 nm to 400 nm range, resulting in the lowest UV-A and UV-B blocking capabilities, and a UPF that does not meet the minimum protection threshold as per the Australian/New Zealand Standard. Although the transmittance of the CO(gCN) sample was reduce by more than half compared to CO(UN), it still fails to achie- ve the minimum required UPF. The CO(TiO ) sample demonstrates very low transmittance in the UV-B range, 2 followed by a sharp increase in the UV-A range, as the energy of these rays is too low to be absorbed by TiO , 2 which also reflected in the UV blocking values, which are higher in the case of UV-B than UV-A. According to the standard, the UPF of CO(TiO ) equal to 20.5 is classified as minimal. In contrast, the CO(TiO /gCN) sample 2 2 exhibits the lowest transmittance, the highest UV-A and UV-B blocking, and the highest UPF value equal to 43.3, which is classified as good. This further confirms the compatibility between TiO and gCN in the nanocomposite. 2 108 29–30 May 2025, Ljubljana, Slovenia Figure 2: Transmittance of untreated and chemically modified samples (a), blocking of UV-A light (b), UV-B light (c), and UPF values (d) The results of the photocatalytic degradation of the RhB dye solution (Figure 3) indicate that CO itself has no photocatalytic activity. Among the chemically modified samples, the CO(gCN) sample shows the slowest and le-ast efficient decolorization of the RhB dye. The CO(TiO ) sample shows a slightly faster decolorization, reaching 2 nearly 100% after 180 minutes. As expected, the CO(TiO /gCN) sample shows the highest photocatalytic activity, 2 as evidenced by the fastest decolorization of the RhB dye solution and the highest degree of decolorization. This behaviour highlights the superior photocatalytic performance of the semiconductor nanocomposite. Additionally, the reduction in E of semiconductor nanocomposite compared to single-component CO(TiO ) sample enhanced g 2 photocatalytic activity under visible light irradiation. Figure 3: Decolorization rate (a) and first-order kinetic plot (b) of the RhB dye solution at different irradiation times in the presence of untreated and chemically modified samples 109 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSION In this study, an environmentally friendly method was successfully applied to functionalize cotton fabric (CO) with TiO /gCN nanocomposites to impart multifunctional properties, i.e enhanced UV protection and photocatalytic 2 activity. CO modified with TiO /gCN nanocomposite reflects more than twice the UPF compared to CO modified 2 with single TiO and gCN components. 2 The highest and fastest decolorization rate of the RhB dye solution was observed for the CO modified with TiO / 2 gCN nanocomposite. This increased photocatalytic activity can be attributed to the formation of a semiconductor nanocomposite, which reduces the E of TiO and gCN compared to the single-components. These results con-g 2 firm the excellent compatibility of TiO and gCN in the semiconductor nanocomposite. 2 Funding: The research was co-founded by the Slovenian Research And Innovation Agency (Program P2-0213, Infrastructural Centre RIC UL-NTF and a Grant for the PhD student D.G.). 5. REFERENCES Hassan, B. S., Islam, G. M. N. and Haque A. N. M. A. 2019. Applications of Nanotechnology in Textiles: A Review. Advance Research in Textile Engineering 4: 1038. Karkare, M. M. 2015. The Direct transition and not Indirect transition, is more favourable for Band Gap calculation of Anatase TiO2 nanoparticles. International Journal of Scientific & Engineering Research 6:12. Nur, A.S.M., Sultana, M., Mondal, A., Islam, S., Robel, F.N., Islam, A. and Sumi, S.A. 2022. A review on the development of elemental and codoped TiO photocatalysts for enhanced dye degradation under UV–vis irradiation. 2Journal of Water Process Engineering 47:102728. Rashid, M.M., Simončič, B. and Tomšič, B. 2021. Recent advances in TiO-functionalized textile surfaces. 2Surfaces and Interfaces, 22, 100890. Shafique, M., Mahr, M.S., Yaseen, M. and Bhatti, H. N. 2022. CQD/TiO nanocomposite photocatalyst for efficient visible light-driven 2 purification of wastewater containing methyl orange dye. Materials Chemistry and Physics 278: 125583. SIST EN 13758-1:2002. Textiles - Solar UV protective properties - Part 1: Method of test for apparel fabrics. Geneva : International Organization for Standardization, 12 p. Su, Y., Chen, P., Wang, F., Zhang, Q., Chen, T., Wang, Y., Yao, K., Lv, W. and Liu, G. 2017. Decoration of TiO /g-C N Z-scheme by carbon 2 3 4 dots as a novel photocatalyst with improved visible-light photocatalytic performance for the degradation of enrofloxacin. RSC Advances 7: 34096. Vasiljević, J., Jerman, I. and Simončič, B. 2021. Graphitic carbon nitride as a new sustainable photocatalyst for textile functionalization. Polymers 13:2568. 110 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding authors: Co-author(s): Barbara Simončič, Prof. Dominika Glažar, Researcher Ivan Jerman, Assist. Prof. and Engineering Hajdrihova ulica 19 Department of Textiles 1000, Ljubljana Department of Textiles Graphic Arts and Design ivan.jerman@ki.s Graphic Arts and Design Aškerčeva cesta 12 Faculty of Natural Sciences Faculty of Natural Sciences Department of Materials Chemistry and Engineering University of Ljubljana University of Ljubljana National Institute of Chemistry Aškerčeva cesta 12 1000, Ljubljana Raghuraj S. Chouhan, Senior Researcher 1000, Ljubljana dominika.glazar@ntf.uni-lj.si Jožef Stefan Institute Department of Environmental Sciences barbara.simoncic@ntf.uni-lj.si Brigita Tomšič, Assoc. Prof. Jamova cesta 39 University of Ljubljana 1000, Ljubljana Faculty of Natural Sciences raghuraj.singh@ijs.si and Engineering Department of Textiles Graphic Arts and Design Aškerčeva cesta 12 1000, Ljubljana brigita.tomsic@ntf.uni-lj.si Danaja Štular National Institute of Chemistry Department of Materials Chemistry Hajdrihova ulica 19 1000, Ljubljana danaja.stular@freudenberg-pm.com 111 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION DEVELOPMENT OF SELF-CLEANING VISCOSE FABRIC FUNCTIONALIZED WITH A TITANIUM DIOXIDE-COUPLED REDUCED GRAPHENE OXIDE IN COMBINATION WITH CHITOSAN Klara Močenik1, Barbara Simončič1 and Brigita Tomšič1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: In this work, viscose fabric was functionalized with a TiO-coupled reduced graphene oxide (rGO) in 2 combination with chitosan to achieve multifunctional UV protection and self-cleaning properties, with a focus on the application process. TiO was applied via a hydrothermal treatment following two approaches: (i) deposition 2 of TiO sol-gel precursor followed by chitosan and rGO and (ii) prior application of chitosan and rGO followed 2 by TiO sol-gel precursor deposition. Scanning electron microscopy (SEM) showed differences in film formation 2 between the two approaches. UV protection and photocatalytic activity were improved when TiO was applied 2 after chitosan and rGO. This resulted in minimum UV protection and superior Rhodamine B degradation. These results underline the importance of the coating sequence for optimising the functional properties for advanced textile applications. Keywords: Textile functionalisation, Titanium dioxide (TiO ), Reduced graphene oxide (rGO), UV protection, 2 Self-cleaning. 1. INTRODUCTION The functionalisation of textiles has developed into an important chemical finishing process that enables produc-tion of textiles with advanced protective properties. Among the various functionalising agents, titanium dioxide (TiO ) is one of the most studied photocatalysts due to its chemical stability, relatively low toxicity and cost-ef-2 fectiveness. These properties make TiO very suitable for the modification of textile surfaces, especially for UV 2 protection, photocatalytically induced self-cleaning and antimicrobial activity (Ijaz, 2021; Peiris, 2021; Rashid, 2021). However, a major disadvantage of TiO in textile finishing is its limited photoactivity in visible light and the 2 insufficient durability of the applied coatings. To improve the photocatalytic performance of TiO in the presence of 2 visible light, it is often modified with precious metals and other photocatalytic materials (Jeon, 2020). Graphene and its derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), have attracted considerable attention due to their unique physicochemical properties. Graphene consists of a monolayer of sp²-hybridised carbon atoms arranged in a hexagonal lattice, which gives it a high specific surface area, exceptional adsorption capacity and excellent electrical conductivity. Thanks to these properties, graphene and its derivatives can act as electron transport mediators, adsorbents, photosensitizers, photostabilisers, photocatalysts and co-catalysts in TiO-based nanocomposites. In addition, the incorporation of graphene alongside TiO has been shown to 2 2 improve the hydrophobicity, UV protection, self-cleaning ability and antimicrobial (antibacterial and antifungal) properties of textiles, while attenuating potentially cytotoxic effects (Stan, 2019). TiO nanoparticles are usually applied to textiles using techniques such as dip coating, sol-gel processes or 2 sputtering (Rashid, 2021). However, their weak interaction with the functional groups of the textile fibres often leads to insufficient adhesion, resulting in poor durability under mechanical stress and repeated washing. Various strategies are used to improve the stability of the coating, including the use of binders or crosslinkers, surface finishing and plasma treatment. Among the crosslinkers, chitosan has shown promise in improving the durabil-ity of TiO coatings. As a biopolymer with inherent biocompatibility and non-toxicity, chitosan not only improves 2 adhesion, but also provides additional antimicrobial functions due to the amine groups (−NH ), which can act as 2 a bio-barrier against microbial growth (Rouhani Shirvan, 2019). However, the incorporation of crosslinkers can 112 29–30 May 2025, Ljubljana, Slovenia alter the photocatalytic efficiency of TiO and impair its functional performance. Therefore, careful optimisation of 2 the application process is crucial to achieve a balance between durability, photocatalytic activity and additional functional properties. The main objective of this research is the functionalisation of viscose fabric with TiO-coupled rGO in combination 2 with chitosan to achieve multifunctional UV protection and self-cleaning properties. Particular attention is paid to the influence of the application process on the performance of the coating. In this context, TiO₂ is applied using a hydrothermal approach in two different steps: (i) first the deposition of the TiO sol-gel precursor followed by the 2 application of chitosan and rGO, and (ii) the prior application of chitosan and rGO followed by the deposition of the TiO sol-gel precursor. This comparative approach aims to investigate the influence of the layer sequence on 2 the structural integrity and functional properties of the resulting coatings. 2. EXPERIMENTAL 2.1 Materials Titanium tetraisopropoxide (TTIP, ≥97.0% concentration), reduced graphene oxide powder (rGO), 1,2,3,4-butan-etetracarboxylic acid (BTCA, 99% concentration), sodium hypophosphite (SHP) and glacial acetic acid were pur-chased from Sigma Aldrich (United States). Chitosan (DD=95%, η=159 mPa∙s) was purchased from Chitoclear, Primex, Iceland. Ethanol (≥99.8% concentration), Rhodamine Blue (RhB) organic dye, and 1.0 mM acetic acid were purchased from Honeywell Research Chemicals (Seetze, Germany) and CARLO ERBA Reagents S.A.S (Barcelona, Spain), respectively. A plain100% viscose fabric with a weight of 110 g/m2 (warp density: 44 threads/ cm; weft density: 34 threads/cm) was used. All reagents are of analytical grade and were used without further purification. 2.2 Preparation of TTIP sol and chitosan/rGO finishing bath A uniform TTIP sol was prepared by dispersing 4% TTIP in an ethanol solution. A small amount of glacial acetic acid was added to the solutions and magnetically stirred for about one hour to perform hydrolysis. Additionally, a 1% chitosan–water solution was prepared with the addition of 1% glacial acetic acid and left magnetically stirred overnight. Prior to finishing, 2% BTCA and 2% of SHP was slowly added to a chitosan–water solution and left to stir, until completely dissolved. Afterwards, rGO powder was added in a concentration of 1 mg/ml and ultrasonicat-ed for 30 minutes to achieve complete and uniform dispersion of rGO powder in a chitosan/BTCA/SHP solution. 2.3 Functionalisation of viscose fabric by TTIP and chitosan/rGO The functionalisation process was carried out in two approaches. In the first approach, TTIP sol was applied to cotton fabric using the pad-dry method with a wet pick-up of 120 ± 5% and then dried at 100 °C for 5 minutes. A chitosan/rGO finishing bath was then applied under the same conditions, resulting in the sample CV_TiO-rGO/ 2 Ch. To investigate the influence of the deposition order on the final properties, in a second approach, chitosan/ rGO was applied, followed by the deposition of the TTIP sol, resulting in the sample CV_Ch/TiO- rGO.In both 2 cases, the treated fabrics were subjected to hydrothermal treatment at 120 °C for 1 hour with constant stirring us-ing an infrared drying machine (Daelim Starlet-2 DL 6000 Plus). The liquor to-goods ratio was maintained at 1:50 throughout the process. After hydrothermal treatment, the samples were rinsed with distilled water and air dried. For comparative analysis, additional samples were prepared by applying individually TTIP sol and TTIP/chitosan onto viscose fabric. The samples are coded CV_TiO and CV_TiO /Ch respectively. 2 2 2.4 Characterization To investigate the surface morphology of the studied samples, scanning electron microscope (SEM) JSM-6060 LV (Jeol, Japan) was used. The transmittance of the functionalized samples was recorded in a 250–780 nm wavelength range using a Lamb-da 800+ UV/Vis spectrophotometer (Perkin Elmer, Great Britain). UV protection factor (UPF) was determined according to the Standard EN 13758-1:2001. The photocatalytic self-cleaning activity of the samples was investigated based on the degradation of the Rhodamine B (RhB, Sigma Aldrich) dye under daylight. Functionalized cotton samples were placed in 4 ml of a 0.2 mMl RhB solution (Sigma Aldrich, USA) and irradiated with daylight using Q-SUN Xe-3-HSE chamber 113 29–30 May 2025, Ljubljana, Slovenia (Q-Lab, Great Britain) for 4 hours at 30 min intervals. The absorbance (A) of the RhB solution was measured at λ of 552.93 nm. Prior to measurements, the calibration curve of the dye concentration ( C) vs. absorbance was max obtained, allowing the determination of the remaining RhB dye in the solution after irradiation. Accordingly, the discolouration of the RhB dye was expressed as a ratio between C and C , representing the RhB concentrations t 0 after time “t” of irradiation and the initial RhB concentration before (time “0”) irradiation. 3. RESULTS WITH DISCUSSION Figure 1 shows SEM images of the investigated samples, which illustrate the morphological changes caused by the nanocoating. The untreated viscose fibres (CV_UN) have a relatively smooth surface with clearly visible characteristic longitudinal grooves. After application of the nanocoating, a continuous film can be seen on the fibre surface of both the CV_TiO₂/Ch-rGO and CV_Ch-rGO/TiO₂ samples, indicating successful deposition. However, local cracks in the coating can be observed in the CV_Ch-rGO/TiO₂ sample, which indicates possible differences in film formation or adhesion strength in relation to the application approach. Figure 1: SEM images of the studied viscose fibres The deposition of TiO₂ significantly decreased transmission of UVA and UVB light, thus increasing UVA and UVB blocking properties, resulting in a 4.5-fold increase in UPF compared to the CV_UN sample (Figre 2 A and B). Accordingly, a UPF of 23 was achieved, which fulfils the requirements for minimum UV protection according to the Australian/New Zealand Standard for Sun-Protective Clothing—Evaluation and Classification (AS/NZS 4399, 2020). In contrast, prior application of TiO-rGO followed by chitosan reduced the UV blocking effect, resulting in 2 a UPF value of 12.5, which is below the protection threshold. However, when TiO-rGO was applied to the fabric 2 subsequently to the chitosan deposition, the UPF increased to 15.6, which is high enough to fulfil the standard for minimum UV protection. Figure 2: UV transmission spectra of the studied viscose fibres (A) and corresponding UV protection parameters (B) In contrast to the UV protection properties, coupling TiO with rGO in the presence of chitosan improved the 2 114 29–30 May 2025, Ljubljana, Slovenia photocatalytic self-cleaning activity, regardless of the application approach (Figure 3). However, between the two approaches studied, again the CV_Ch/TiO-rGO with subsequent application of TiO proved better performance. 2 2 This improvement in self-cleaning activity can be attributed to the presence of rGO, which plays a crucial role in facilitating charge separation and electron transfer. According to literature, the coupling of TiO with rGO promotes 2 a more efficient transfer of photogenerated electrons from the conduction band of TiO to the neighbouring rGO 2 surface, where they subsequently reduce O molecules and generate superoxide radicals (). At the same time, 2 the corresponding holes in the valence band of TiO interact with the hydroxyl groups (−OH) on the surface, which 2 leads to the formation of highly reactive hydroxyl radicals (•OH). These reactive oxygen species (ROS) then degrade the adsorbed RhB dye molecules on the TiO /rGO surface and thus increase the overall photocatalytic 2 efficiency (Alwan 2022; Yu, 2018). Figure 3: Discolouration of the RhB dye over time under irradiation of the tested samples 4. CONCLUSIONS In the study, a viscose fabric was successfully functionalized with TiO-coupled rGO in the presence of chitosan 2 to achieve multifunctional UV protection and self-cleaning properties. While the coupling of TiO with rGO in the 2 presence of chitosan impaired the UV protection activity, it improved the photocatalytic self-cleaning activity by enhancing charge separation and ROS formation. Among the investigated approaches, the subsequent TiO-rGO 2 coupling in the presence of previously applied chitosan proved to be better. These results underline the impor-tance of optimising the coating strategy to achieve a balance between multifunctional UV protection and photo-catalytic self-cleaning efficiency. Funding: This research was founded by the Slovenian Research and Innovation Agency (Programme P2-0213 Textiles and Ecology, Infrastructural Centre RIC UL-NTF). 115 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Alwan, S. H., Salem, K.H. and Alshamsi, H.A. 2022. Visible light-driven photocatalytic degradation of Rhodamine B dye onto TiO2/rGO nanocomposites, Materials Today Communication 33: 104558. Ijaz, M. and Zafar, M. 2021. Titanium dioxide nanostructures as efficient photocatalyst: Progress, challenges and perspective. International Journal of Energy Resourch 45: 3569–3589. Jeon, J. P., Kweon, D. H., Jang, B. J, Ju, M. J. and Baek, J. B. 2020. 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ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Brigita Tomšič Barbara Simončič Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana and Engineering Aškerčeva cesta 12 Aškerčeva cesta 12 1000, Ljubljana 1000, Ljubljana barbara.simoncic@ntf.uni-lj.si brigita.tomsic@ntf.uni-lj.si Klara Močenik University of Ljubljana Faculty of Natural Sciences and Engineering Aškerčeva cesta 12 1000, Ljubljana km89154@student.uni-lj.si 116 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION FABRICATION OF DURABLE ELECTROCONDUCTIVE FIBROUS COMPOSITES FOR WEARABLE ELECTRONICS Alenka Ojstršek1 and Laura Jug1 1University of Maribor, Faculty of Mechanical Engineering, Slovenia Abstract: The aim of this study was, firstly, to synthesise titanium carbide (Ti C T MXene) nanosheets in two 3 2 x different sizes according to the pre-optimised procedure from two-sized Ti AlC MAX phase precursors, using a 3 2 sustainable synthesis approach. MXenes‘ surface morphologies were inspected by Scanning Electron Micros-copy (SEM). Secondly, the synthesised nanosheets were applied onto cotton fabric by dip-padding procedure and protected with three different compounds, i.e., modified acrylate resin (MAR), waterborne polyurethane resin (WPR) and biantennary oligoglycine peptide (TEC), which was confirmed by Fourier Transform Infrared (FTIR) spectroscopy. Finally, MXene-functionalised/protected samples were washed up to 20 washing cycles and cha-racterised by measuring their electrical resistance, changes in surface morphologies and water contact angles. Based on these results, WPR provided the most suitable protection of MXenes on cotton fabric, followed by MAR, balancing high conductivity with long-term stability. TEC is not recommended for MXene protection due to its low durable performance against harsh washing conditions. Keywords: MXene, electroconductivity, washing durability, flexibility, wearable electronics 1. INTRODUCTION Wearable electronic systems typically require conductive tracks to form electrical interconnections between com-ponents. Recently, a new family of two-dimensional (2D) materials, the transition metal carbide and nitride, called MXenes, have shown great promise as potential compounds for this purpose on account of their high electrical conductivity (up to 20,000 S/cm), tuneable surface chemistry, high strength and stiffness, good hydrophilicity, scalable solution synthesis (kg batches), sufficient environmental stability, biocompatibility, aqueous solution pro-cessing without surfactants addition, etc. (Wang et al., 2019). It is widely known that the morphological structures of MXenes, especially their size distribution, when applied to textile surfaces, strongly influence the textiles’ final properties (Wang et al., 2021). Herein, the larger nanoflakes lead to higher electrical conductivity and mechanical strength than smaller ones. Moreover, fibrous materials mod-ified with larger MXenes usually have a higher loading percentage and, thus, higher electrical conductivity. At the same time, large flakes can affect the fibres’ flexibility negatively, as well as reduce the fibres-MXene adhesion, and, consequently, cause low wear and/or wash durability during long-term usage. Due to the inhomogeneity and roughness of textiles as well as the small sheet size and weak interlayer interaction between MXene sheets, the MXenes employment often does not lead to permanent effects on the textile surfaces during daily use - limited wash durability (Ojstršek et al., 2021). Moreover, it is necessary for MXene to avoid its restack and oxidisation upon exposure to water, mechanical forces and high temperatures, which can hinder its relative capacitance and stability. Thus, diverse polymers can be applied as encapsulants to prevent oxidation and peeling off the conductive tracks without negligible effect on the fabrics’ comfort, flexibility and wearability, which is the aim of the presented study. 117 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL 2.1 Materials An industrially bleached plain-waived cotton fabric was used for the trials with a mass/unit area of 92.7 ± 0.6 g/ m2, warp density of 51 threads/cm, weft density of 44 threads/cm, and thickness of 0.18 mm. Two sizes of Ti C T 3 2x MXene flakes were synthesised, small- (S) and large-size (L), from 1 g of Ti AlC MAX precursor powders (in two 3 2 sizes, 40 and 100 µm) by a pre-optimised top-down minimally intensive layer delamination (MILD) approach as detailly described in (Jug et al., 2025), obtaining a stable dark green supernatant solution with pH 6 with a swelling clay precipitate. 2.2 Application of small- and large-sized MXene nanosheets and their protection The individual cotton (Co) fabric sample (2×2 cm2) was dipped three times into 10 mL MXene aqueous dispersion (10 mg/mL) for 5 min, followed by an intermediate/final vacuum-assisted drying at 60 °C, preparing two samples (CoS and CoL). Afterwards, individual polymer, i.e., modified acrylate resin (MAR), waterborne polyurethane resin (WPR) or 2-tailed tectomer (TEC), was applied over MXene-functionalised fabrics using pre-optimised pad-dry-ing. In addition, MXene-functionalised and MXene-coated/protected cotton fabrics were washed up to 20 times (washing cycles) at a temperature of 40 °C for 30 min, using standard reference detergent in a concentration of 1 g/L and a liquor-to-fabric weight ratio of 50:1, with the aim to evaluate fabrics’ washing durability. After each washing cycle, the samples were rinsed in tap water for 1 min and then dried at 60 °C for 20 min. 2.3 Analytical procedures Scanning Electron Microscopy (SEM) was applied by means of a Zeiss Gemini Supra 35 VP Scanning Electron Microscope (Carl Zeiss NTS GmbH), with a maximum scan resolution of up to 1.5 nm at 1 kV, for the inspection of morphologies of synthesised MXene nanosheets and MXene-functionalised samples. In addition, the size distribution was carried out from SEM micrographs of at least 100 randomly chosen nanosheets, employing ImageJ, an image-processing program. Fourier Transform Infra-Red (FTIR) spectroscopic measurements of MX-ene-functionalised/protected samples were performed using a Spectrum GX spectrophotometer (Perkin Elmer) with a Golden Gate ATR attachment and a diamond crystal. A two-point probe multimeter 34410A 6 1/2 Digit (Agilent Technologies) was used for measuring the electrical resistance of samples across the entire surface area between two consistently sealed connections before and after 5, 10, 15 and 20 washing cycles. The Water Con-tact Angle (WCA) of MXene-functionalised/protected samples before and after 20 wash cycles was performed by means of the goniometer OCA 35 (DataPhysics Instruments) using the sessile drop technique. 118 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS AND DISCUSSION 3.1 SEM analysis of MXenes The morphological structures of two different MXenes flakes are presented in Figure 1 together with the size dis-tribution diagrams. Figure 1: SEM images of MXenes and corresponding average flake-size distribution histograms: small flakes (left); and large 29–30 May 2025, Ljubljana, Slovenia flakes (right) SEM micrographs in Figure 1 revealed the successful synthesis of MXenes flakes with well-defined sharp edges. Approximately twice as small MXene flakes in lateral size can be observed on the left micrograph as compared to the flakes on the right, employing similar etching conditions due to two different initial sizes of used MAX phase SEM micrographs in Figure 1 revealed the successful synthesis of MXenes flakes with well-defined sharp precursors. Thus, the flakes with an average diameter of 2373 nm (left) and 4663 nm (right) were determined edges. Approximately twice as small MXene flakes in lateral size can be observed on the left micrograph as from the flake-size distribution histograms. As explained in (Wang et al., 2021), the larger the flake size is, the compared to the flakes on the right, employing similar etching conditions due to two different initial sizes of smaller the interfacial resistance between the flakes, implying higher overall MXenes’ electrical conductivity and, used MAX phase precursors. Thus, the flakes with an average diameter of 2373 nm (left) and 4663 nm (right) consecutively, higher electrical conductivity of MXene-decorated fabric. were determined from the flake-size distribution histograms. As explained in (Wang et al., 2021), the larger the flake size is, the smaller the interfacial resistance between the flakes, implying higher overall MXenes' electrical conductivity and, consecutively, higher electrical conductivity of MXene-decorated fabric. 3.2 FTIR analysis of MXene/polymer-coated samples Figure 2 depicts the FTIR results of selected large-sized MXene-functionalised/protected samples. 3.2 FTIR analysis of MXene/polymer-coated samples Figure 2 depicts the FTIR results of selected large-sized MXene-functionalised/protected samples. Figure 2: FTIR spectra of untreated cotton (Co), MXene-functionalised (CoL) and MXene-functionalised/protected samples Figure 2: FTIR spectra of untreated cotton (Co), MXene-functionalised (CoL) and MXene-(CoL-MAR, CoL-WPR and CoL-TEC) functionalised/protected samples (CoL-MAR, CoL-WPR and CoL-TEC) As noticed from Figure 1, the pristine cotton fabric shows a broad peak around 3200-3400 cm‒1, which was attributed to the stretching of the O‒H groups; the peak near 2890 cm‒¹ was assigned to the band of C‒H stretching vibrations, and the peak at 1210 cm‒1 was the stretching of the C‒O bond (Lv et al., 2018). After the application of MXenes, the characteristic peaks for cotton are lowered. A similar was perceived for the TEC- protected sample, implying that the MXene peak dominates over characteristic peptide peaks of TEC. 119 Additionally, the MXene-modified/WPR-protected cotton spectrum has completely attenuated cotton peaks and shown absorption bands corresponding to N‒H (3340 cm‒¹), C‒H (2920 cm‒¹), C=O (1720 cm‒¹), C‒N (1240 cm‒¹), and C‒O‒C (1100‒1250 cm‒¹) bonds, significant for WPR. For the sample protected with MAR, 29–30 May 2025, Ljubljana, Slovenia As noticed from Figure 1, the pristine cotton fabric shows a broad peak around 3200-3400 cm‒1, which was at-tributed to the stretching of the O‒H groups; the peak near 2890 cm‒¹ was assigned to the band of C‒H stretching vibrations, and the peak at 1210 cm‒1 was the stretching of the C‒O bond (Lv et al., 2018). After the application of MXenes, the characteristic peaks for cotton are lowered. A similar was perceived for the TEC-protected sample, implying that the MXene peak dominates over characteristic peptide peaks of TEC. Additionally, the MXene-mod-ified/WPR-protected cotton spectrum has completely attenuated cotton peaks and shown absorption bands cor-responding to N‒H (3340 cm‒¹), C‒H (2920 cm‒¹), C=O (1720 cm‒¹), C‒N (1240 cm‒¹), and C‒O‒C (1100‒1250 cm‒¹) bonds, significant for WPR. For the sample protected with MAR, the most prominent peak appears at ∼1720 cm‒¹ (C=O), at ∼1140 cm‒¹ (C‒O in the ester groups), and at 2950‒2860 cm‒¹ (C‒H) (Salih et al., 2015). 3.3 Washing durability of MXene/polymer-coated samples In order to evaluate the effectiveness of three selected compounds (MAR, WPR and TEC) for the protection of MXenes onto cotton fabric against peeling off and oxidation due to the combined action of water, temperature and mechanical forces, MXene-functionalised/polymer-protected samples were washed up to 20 cycles and charac-terised in terms of electrical resistance measurement (Figure 3) and WCAs determination (Figure 4). Figure 3: SEM micrographs of CoL sample before and after 20 washing cycles (left); and the electrical resistance of MXene/ polymer-coated samples relative to the initial value after 5, 10, 15 and 20 washes (right) The morphological characteristics of the selected MXene-coated fabric, i.e., CoL sample (Figure 3 - left), exhib-ited rough and rugged areas, indicating a tight coating of MXene nanosheets around the fibres and filled spaces between them. After 20 washings, the MXenes remained on the surface, although significant cracks were noticed, increasing the electrical resistivity tremendously (up to 2494 Ω·cm). Therefore, the surface of MXene-coated sam-ples was further protected with the selected three polymers. Both WPR-protected samples, CoS-WPR and CoL-WPR, exhibited a minimal raising of resistance after 5 wash-es, i.e., for 4.99% and 3.34 %, respectively, compared to their starting values (Figure 3 - right). Moreover, WPR protective coating maintained the electrical resistance of the fabrics effectively at a satisfactory level even after 20 washings. A similar trend was observed in MAR-treated samples with adequate protection during the early washing cycles, with a resistivity of 12.81 Ω·cm (CoS-MAR) and 6.34 Ω·cm (CoL-MAR) after five washes. Never-theless, if the number of washing cycles exceeds 10, the resistivity rapidly escalates and can eventually reach the resistance level of untreated raw samples, losing electrical conductivity. The least effective protective compound was TEC, wherein the electrical resistivity was significantly dependent on the flake sizes of applied MXenes. 120 29–30 May 2025, Ljubljana, Slovenia Figure 4: WCA of MXene-coated and MXnene/polymer-coated samples before and after 20 washings The WCA analysis (Figure 4) gives contact angles of ∼60 ° for MXene-coated unprotected (CoS and CoL) sam-ples, presumably on account of the inherent hydrophilic nature of both MXenes and the cotton. On the contrary, the MXene-functionalised/MAR- or WPR-protected samples had excellent hydrophobic properties with high con-tact angles of around 100°, regardless of the MXene nanosheet’s lateral size. The protected samples remained hydrophobic even after 20 washing cycles, decreasing the WCA for 6° (CoS-MAR), 10° (CoL-MAR), 13° (CoS-WPR) and 22° (CoL-WPR), which demonstrates the robustness and efficacy of the coating in preserving the surface’s hydrophobic properties. Meanwhile, TEC was the least effective compound for the protection of MXenes against washings since the water drop spread immediately after surface contact after 20 washes. Consequently, water quickly penetrates through the pores during repeated washings, causing a loss of conductivity, as previous-ly confirmed by an enlargement in electrical resistance. 4. CONCLUSION In the presented study, Ti C T MXene flaxes in two sizes were prepared successfully employing two-sized Ti AlC 3 2 x 32 MAX phase precursors. Both the small- and large-sized Ti C T MXene nanosheets (in lateral size) were further-3 2 x more evenly applied onto cotton fabric by the pre-optimised dip-padding procedure. The larger MXene flakes imply higher electrical conductivity but lower adhesion and a greater tendency to oxidation. Thus, three different protective compounds were applied to MXene-functionalised fabric, and two of them (WPR and MAR) significantly enhanced the fabric’ hydrophobicity even after 20 washing cycles, expanding the potential applications of MX-ene-decorated fabrics in smart textile applications by providing good durability of electroconductive functionalisa-tion. TEC is not recommended for MXene protection due to its low adhesion and poor hydrophobic performance. 5. ACKNOWLEDGEMENTS The results leading to this work were funded by the Slovenian Research and Innovation Agency (ARIS) in the frame of research project no. J2-50087, bilateral project no. BI-VB/25-27-022 and a research core program group for Textile Chemistry and Advanced Textile Materials P2-0118 within the Young Researchers Programme. 121 29–30 May 2025, Ljubljana, Slovenia 6. REFERENCES: Jug, L., Hribernik, S., Ojstršek, A. “Synergic effect of large MXene nanosheets and protective coatings on improved electroconductivity and wash durability of MXene/polymer-modified cotton fabric.” Progress in Organic Coatings 200 (2025) 109062. Lv, N., Wang, X., Peng, S., Luo, L., Zhou, R. “Superhydrophobic/superoleophilic cotton-oil absorbent: preparation and its application in oil/ water separation.” RSC advances 8 (2018) 30257−30264. Ojstršek, A., Plohl, O., Gorgieva, S., Kurečič, M., Jančič, U., Hribernik, S., Fakin, D. “Metallisation of Textiles and Protection of Conductive Layers: An Overview of Application Techniques.” Sensors 21 (2021) 3508. Salih, A.M., Ahmad, M.B., Ibrahim, N.A., Dahlan, K.Z.H.M., Tajau, R., Mahmood, M.H., Yunus, W.M.Z.W. “Synthesis of Radiation Curable Palm Oil–Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations.” Molecules 20 (2015) 14191−14211. Wang, Q.-W., Zhang, H.-B., Liu, J., Zhao, S., Xie, X., Liu, L., Yang, R., Koratkar, N., Yu, Z.-Z. “Multifunctional and Water-Resistant MXene-Decorated Polyester Textiles with Outstanding Electromagnetic Interference Shielding and Joule Heating Performances.” Advanced Functional Materials 29 (2019) 1806819. Wang, X., Fan, X., Li, M., Zhu, W., Xue, J., Ye, F., Cheng, L. “Structure and electromagnetic properties of Ti C T MXene derived from 3 2 x Ti AlC with different microstructures.” 47 (2021) 13628–13634. 3 2 Ceramics International ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Alenka Ojstršek Laura Jug Faculty of Mechanical Engineering Faculty of Mechanical Engineering, Institute of Engineering Institute of Engineering University of Maribor University of Maribor, Materials and Design Materials and Design Smetanova 17 Smetanova 17 2000 Maribor, Slovenia 2000 Maribor, Slovenia +386 2 220 7652; laura.jug@um.si +386 2 220 7935; alenka.ojstrsek@um.si 122 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION ECO-FRIENDLY HYDROPHOBIC TEXTILES: A SHIFT FROM PFAS TO SUSTAINABLE BIO-POLYMERS Barbara Golja1,2, Blaž Stres2, Uroš Novak2, Blaž Likozar2 and Anja Verbič2* 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2 National Institute of Chemistry, Slovenia Abstract: Identifying efficient and long-lasting textile coatings that can serve as alternatives to toxic per- and poly-fluoroalkyl substances (PFAS) is essential for a future free from harmful fluorinated chemicals. For this purpose, a hydrophobic cotton (CO) and polyester (PES) textile fabric was produced using natural biopolymers in the form of microcapsules. The CO and PES samples were coated with dippaddry process and the fabric visual appearance, colour measurements, thickness, morphology and hydrophobicity were evaluated before and after coating. The visual appearance of the fabric did not change significantly with the application of coating, which was confirmed by CIELAB colour measurements. The increase in thickness of the fabric was minimal. The water contact angle increased from highly hydrophilic (<10°) to hydrophobic (above 120°) after the coating application. The research showed that with the use of biopolymers which are environmentally and human health friendly, hydrophobicity of natural and synthetic textile fabrics can be achieved. Keywords: water-repellence, hydrophobicity, biopolymers, biomaterials, coatings, textile 1. INTRODUCTION Per- and polyfluoroalkyl substances (PFAS) are a large group of more than 4700 (OECD, 2018) synthetic com-pounds characterized by the presence of strong carbon-fluorine (C-F) bonds, that provide exceptional thermal, chemical, and mechanical stability (Li, 2018). Simultaneous hydrophobic and oleophobic properties make PFAS highly valuable in various industrial applications, such as personal care products, cosmetics, cleaning products, textile coatings for stain and water repellency, food contact materials, adhesives, non-stick pans, medical devic-es, various membranes, fire-fighting foams, etc. (Panieri, 2022; Gluge, 2020; Gaines, 2023; Kleinman, 2021). However, due to their chemical composition, these compounds are very persistent in the environment, difficult to degrade, and tend to bioaccumulate, leading to significant concerns about potential adverse effects on human health and ecosystems (Wee, 2023). They have been detected in groundwater, surface water and soil worldwide, raising alarms about their longterm effects on the environmental and human exposure (Merino, 2016; Ahrens, 2014; EPA, 2023). People get exposed to PFAS through various pathways, including contaminated water and soil, food chain accumulation, household dust, and others (Karaskova, 2016; Worley, 2017; Lin, 2020; Sadia, 2023; Smalling, 2023), which has been linked to numerous health problems, including reproductive problems, endocrine disruption, immune system effects, infertility, developmental problems in children, weakened immune system, higher cholesterol levels and increased cancer risk (Panieri, 2022; Fenton, 2021; Blake, 2018; EPA, 2023; Bartell, 2021). Because of extensive evidence linking PFAS to serious health effects, addressing PFAS con-tamination is critical to protect not only the environment but also public health. In response, significant regulatory measures and limitations have been implemented worldwide. Authorities are monitoring the use, manufacture, and disposal of PFAS compounds, and have specified allowable levels of certain PFAS substances in water, soil and air to minimize their release into the environment and reduce associated health risks (EPA, 2023). In addi-tion, regulations have limited the production and use of other PFAS compounds, such as perfluorooctanoic acid (PFOA) and perfluoroctanesulfonic acid (PFOS) (EPA, 2023). Current initiatives aim to completely eliminate the use of PFAS by banning the production and sale of PFAS-containing textiles and proposing bans or restrictions on up to 12,000 different compounds (NY State department of environmental conservation, 2023; ChemRadar, 2024; Spyrakis, 2023). As a result, industries, including the textile sector, are being urged to find PFAS-free alternatives, that can provide similar benefits without the associated risks, to comply with these regulations. Current synthetic 123 29–30 May 2025, Ljubljana, Slovenia alternatives to PFAS, such as silicones (Jin, 2018), alkylamines (Lin, 2021), acrylates (Messerschmidt, 2018) and melamine (Zheng, 2020), still have their own environmental concerns. These synthetic compounds may still leave a chemical footprint and may not completely solve the problem of pollution and toxicity. A better and more sustain-able option would be to move towards the use of natural, renewable materials, which would provide the desired properties without the harmful environmental impact. The literature review showed, that using biomaterials, hy-drophobicity can be achieved either by using low surface energy compounds or by increasing surface roughness (Shahid, 2022). To reduce surface energy, natural compounds such as fatty acids and their salts (Shahid, 2022), or natural waxes like beeswax and carnauba wax have been used (Shahid, 2022). Surface roughening has been achieved through enzyme etching or by applying various nanostructures derived from natural materials (Shahid, 2022), which mimic the lotus leaf effect. Combinations of both approaches can be used to achieve higher levels of hydrophobicity. However, the literature review showed that most of these formulations still involve various chem-icals and/or solvents, indicating that the formulations are not completely biomaterial-based and can still pose a level of environment burden and health risks. To address these concerns, it is preferable to use solely natural biomaterials, which can be either chemically modified to achieve hydrophobic properties if they are inherently hydrophilic, or by combining multiple biomaterials to achieve synergistic effects. This is especially promising due to growing interest in biodegradable polymers, derived from renewable sources. The same approach to hydrophobic coatings development is also used in the Horizon Europe PROPLANET project. Within the project, natural biopolymer-based hydrophobic coatings for textile applications are being de-veloped in alignment with the Safe and sustainable by Design (SsbD) principles to ensure the use of safer and more sustainable materials. One of the ways the project aims to achieve that is by using natural biomaterials in the form of microcapsules (Figure 1). Figure 1: Schematic presentation of a hydrophilic fabric and a hydrophobic fabric achieved with application of coating with microcapsules. 2. EXPERIMENTAL 2.1 Materials Bleached and mercerized plain weave 100% cotton (CO) woven fabric (185 g⁄m2, warp density 26 threads/cm, weft density 24 threads/cm) from Europrint (Ajdovščina, Slovenia) and polyester (PES) fabric (185 g/m2, warp density 21 threads/cm, weft density 17 threads/cm) fabric from Svet Metraže (Ljubljana, Slovenia) were used as substrates for the coating. A suspension of biopolymer-based microcapsules (MC) was prepared using a combi-nation of natural biopolymers. For all of the experiments in the research Milli-Q pure water was used. 124 29–30 May 2025, Ljubljana, Slovenia 2.2 Methods 2.2.1 Sample preparation CO and PES fabric samples measuring approximately 35x40 cm were used for coating application, which was carried out using the dippaddry process. The samples were immersed into glass impregnation bath containing coating solution and then squeezed between the rollers of a two-roller foulard (Mathis, Switzerland) to achieve a wet pick up of 80 %, and dried in a laboratory continuous dryer (Mathis, Switzerland) at 40 °C for 5 minutes. The coating formulation was developed as a part of the PROPLANET project and its manufacturing process is protect-ed by the project’s intellectual property. 2.2.2 Analysis Colour measurements Colour coordinate (CIE L*a*b*) values of the samples were measured using the Datacolor Spectro 1050 reflec-tance spectrophotometer (Datacolor, Luzern, Switzerland). Measurements were made with a d/8° measurement geometry, under D65 illumination, 10° standard observer, with specular reflectance included, with a 9-mm ap-erture. Four layers of the sample were used for the measurements and an average of five measurements was reported. Sample thickness The thickness of the samples was measured with digital caliper Mitutoyo ID-C112X (Mitutoyo, Japan) with an 8 mm stem diameter and ≤ 1.5N measuring force. Five measurements of each sample were taken, and the average value was reported. Scanning electron microscopy (SEM) The surface morphology of the samples was analysed using scanning electron microscope JSM-6060 LV (Jeol, Japan). Prior to observation the samples were coated with a thin layer of gold. The coated samples were observed directly after coating. SEM micrographs were taken at a beam voltage 10kV, working distance 16 mm, 30 beam spot size and a magnification of 50x. Water contact angles (WCA) The water repellence of the control (uncoated) and coated samples was evaluated by measuring WCA. For this analysis, tensiometer Theta T200 (Biolab Scientific, Gothenburg, Sweden) was used. The static contact angle was determined at 5 seconds after the beginning of the measurement. 3. RESULTS WITH DISCUSSION The presented research aimed to achieve hydrophobic CO and PES textile substrates by using only natural bio-polymers. Our purpose was not only to replace PFAS with other fluorinated compounds, which are currently in broad use and are being phased out by various regulations, but to use only natural substances which are renew-able, biodegradable, can be recycled and are not harmful for the environment and human health. Since it is crucial for practical applications that the coating not only enhances functionality of textiles, but also preserves the fabric’s original properties and appearance, while ensuring suitability for use and handling, we first checked the visual appearance of the samples. This involved visual assessment and hand-feel, determining the sample thickness and measuring the colour values. To effectively compare the properties of fabrics, we deter-mined the properties of both untreated (control) and coated fabrics. The visual differences between the untreated and coated CO and PES were minimal (Figure 2a-d). The handfeel of the coated samples was similar to the con-trol ones, although there was a subtle feel of coating presence on the fabric, determined by slightly more textured and stiffer surface. To determine the colour differences quantitatively, CIE L*a*b* colour values of the control and coated CO and PES samples were measured. The results show (Figure 2) that the lightness values (CIE L*) of both control samples are slightly higher than of the belonging coated samples, meaning that by application of the coating, the samples become slightly darker. The values of the green–red colour coordinates (CIE a*) are on the red side of the colour coordinate for CO and PES samples, control and coated ones. After the coating application the values decrease for both CO and PES fabric, which is more evident in the case of cotton samples, meaning that the coated samples are less red than the uncoated ones. The values of the blue–yellow coordinate are on 125 29–30 May 2025, Ljubljana, Slovenia the blue side of the colour coordinate for all four samples. The biggest difference in the CIE b* values are seen between control and coated cotton sample, where the CIE b* value decreases from -15.95 to -5.59 after coating application, meaning that the samples become less blue. This is also noticeable with the naked eye, as coated CO sample is slightly less blue and more yellow than the control one. This small difference in colour values is due to the thin layer of coating that does not significantly affect the sample’s appearance. This is also evident from the results of thickness measurements (Figure 2) which show, that with coating application, the thickness increases minimally, by 0,05 mm for CO and by 0,01 mm for PES. Figure 2: Visual appearance, thickness and CIE L*a*b* values of the control and coated CO and PES. According to the results above, the coating has minimal influence on the original properties of CO and PES fab-ric. To check more precisely how the application of coating influences the surface morphology of the fabric, SEM analysis was carried out. SEM micrograph of coated sample (Figure 3b) shows the presence of microcapsules, which are spherical and mostly evenly distributed over the surface of the fabric, with some individual aggregates observed. How their presence influences the water repellency of the coated material in comparison to the control sample, was determined through measuring the static contact angle with water. The hydrophobicity of material is achieved when the water droplets do not spread or wet its surface. The boundary between wetting and repellency is defined by the contact angle of the liquid droplet on the textile substrate. If the contact angle is less than 90°, the textile is wettable, but if the contact angle is greater than 90°, the textile substrate is repellent. In other words, an increase in the contact angle means an increase in repellency (Law, 2014). Our measurements showed that the untreated samples are highly hydrophilic, to the extent that it is not possible to determine a measurable WCA with the standardized procedure. Therefore, the WCA was determined as <10° (Figure 3c). After the coating ap-plication the WCA increased to above 120°, meaning that the samples are hydrophobic (Figure 3d), which is also evident from the WCA images. 126 29–30 May 2025, Ljubljana, Slovenia Figure 3: SEM micrographs of a) control PES fabric and b) coated PES fabric at magnification 50x and WCA value with the image of droplet of c) control and d) coated PES fabric. 4. CONCLUSIONS The aim of this research was to produce hydrophobic textile fabric using natural, biodegradable compounds that are safe for human health and environment. Our innovative coating was developed using natural biopolymers in the form of microcapsules. Application of the coating did not significantly alter the appearance, colour or thick-ness of the CO and PES fabrics. SEM micrographs showed an even distribution of the microcapsules across the fabric surface. The WCA values increased from < 10° for untreated fabric to above 120° for coated fabric, which is comparable to commercial hydrophobic coatings. Unlike fluorine-based coatings, the developed formulation is non-toxic, biodegradable and safe for the environment and human health. In conclusion, this research has shown that hydrophobic properties of textile fabrics can be achieved using biopolymers as renewable sources in an en-vironmentally friendly, sustainable way, which is a much safer alternative to traditional PFAS. Additional analysis has to be performed to determine the coating’s durability in comparison with commercial coatings, as this will be crucial for assessing their long-term performance, effectiveness and viability in practical applications. 5. REFERENCES Ahrens, L., Bundschuh, M. 2014. “Fate and effects of poly- and perfluoroalkyl substances in the aquatic environment: a review”. Environmental Toxicology and Chemistry 33(9): 1921-1929. Bartell, S. M., Vieira, V. M. 2021. “Critical review on PFOA, kidney cancer, and testicular cancer.” Journal of the Air & Waste Management Association 71(6): 663-679. Blake, B. E, Pinney, S. M, Hines, E. P., et al. 2018. “Associations between longitudinal serum perfluoroalkyl substance (PFAS) levels and measures of thyroid hormone, kidney function, and body mass index in the Fernald Community Cohort.” Environmental pollution 242: 894-904. ChemRadar. 2024. “Japan proposes to designate 138 perfluorinated compounds as Class I Specified Chemical Substances”. URL: https:// www.chemradar.com/news/detail/dz1n895bhdz4 (last accessed on 30.1.2025). Gaines, L. 2023. “Historical and current usage of per- and polyfluoroalkyl substances (PFAS): A literature review.” Am J Ind Med. 66: 353–378. Gluge, J. et al. 2020. “An overview of the uses of per- and polyfluoroalkyl substances (PFAS).” Environ. Sci.: Processes Impacts 22: 2345. EPA – United Stated Environmental protection Agency. Our Current Understanding of the Human Health and Environmental Risks of PFAS. 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Law, K-Y. 2014. “Definitions for Hydrophilicity, Hydrophobicity, and Superhydrophobicity: Getting the Basics Right.” The Journal of Physical Chemistry Letters 5(4): 686-688. Li, Y., Oliver, P. D., Kookana S. R. 2018. “A critical analysis of published data to discern the role of soil and sediment properties in determining sorption of per and polyfluoroalkyl substances (PFASs).” Science of the Total Environment 628-629: 110-120. Lin, Y., Jiang, J. J., Rodenburg, L. A., et al. 2020. “Perfluoroalkyl substances in sediments from the Bering Sea to the western Arctic: Source and pathway analysis.” Environment international 139: 105699. Lin, T. C., Lee, D. J. 2021. “Cotton fabrics modified with tannic acid/long-chain alkylamine grafting for oil/water separation.” Journal of the Taiwan Institute of Chemical Engineers 127: 367-375. Merino, N., Qu, Y., Deeb, A., R., Hawley, E., R., Hoffmann, M. R., Mahendra, S. 2016. “Degradation and Removal Methods for Perfluoroalkyl and Polyfluoroalkyl Substances in Water.” Environmental Engineering Science 33(9): 615-649. Messerschmidt, M. et al. 2018. “Fluorocarbon-Free Dual-Action Textile Finishes Based on Covalently Attached Thermoresponsive Block Copolymer Brush Coatings.” ACS Appl. Mater. Interfaces 10: 40088−40099. New York State Department of Environmental Conservation. 2023. »PFAS in apparel law.« URL: https://dec.ny.gov/environmental-protection/help-for-businesses/pfas-in-apparel-law (last accessed on 30.1.2025) OECD, Toward a new comprehensive global database of per- and polyfluoroalkyl substances (PFASs): Summary report on updating the OECD 2007 list of per- and polyfluoroalkyl substances (PFASs). 2018, Environment Directorate. Panieri, E., Baralic, K., Djukic-Cosic, D., Buha Djordjevic, A., Saso, L. 2022. “PFAS molecules: a major concern for the human health and the environment.” Toxics 10(2): 44. Sadia, M., Nollen, I., Helmus, R., Laak, T. L., Béen, F., Praetorius, A., van Wezel, A. P. 2023. “Occurrence, Fate, and Related Health Risks of PFAS in Raw and Produced Drinking Water.” Environmental Science Technology 57(8): 3062–3074. Shahid, M., Maiti, S., Adivarekar, R. V., Liu, S. 2022. “Biomaterial based fabrication of superhydrophobic textiles – A review.” Materials today chemistry 24: 100940. Smalling, K. L., Romanok, K. M., et al. 2023. “Per- and polyfluoroalkyl substances (PFAS) in United States tap water: comparison of underserved private-well and public-supply exposures and associated health implications.” Environment International 178: 108033. Spyrakis, F., Dragani, T. A. 2023. “The EU’s per-and Polyfluoroalkyl substances (PFAS) ban: A case of policy over science.” Toxics, 11(9): 721. Wee, S. Y., Aris, A. Z. 2023. “Environmental impacts, exposure pathways, and health effects of PFOA and PFOS.” Ecotoxicology and Environmental Safety 267: 115663. Worley, R. R., Moore, S. M., Tierney, B. C., et al. 2017. “Per-and polyfluoroalkyl substances in human serum and urine samples from a residentially exposed community.” Environment international 106: 135-143. Zheng, G., Salamova, A. 2020. “Are Melamine and Its Derivatives the Alternatives for Per- and Polyfluoroalkyl Substance (PFAS) Fabric Treatments in Infant Clothes?” Environ. Sci. Technol. 54: 10207-10216. Funding: This research was supported by Horizon Europe project PROPLANET (Grant agreement number 10109842) and Slovenian Research Agency (Research core funding No. P2-0152). 6. ACKNOWLEDGMENTS: The authors would like to thank Vuk Martinović and Petja Logar with the help with the experimental work and Ivan Jerman for access to equipment for the measurements of WCA. 128 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Anja Verbič Barbara Golja Uroš Novak and Chemical Reaction Engineering Faculty of Natural Sciences and Chemical Reaction Engineering and Enginering National Institute of Chemistry National Institute of Chemistry Department of Catalysis University of Ljubljana Department of Catalysis Hajdrihova 19 Department of Textiles, Hajdrihova 19 1000 Ljubljana, Slovenia Graphic arts and Design 1000 Ljubljana, Slovenia Aškerčeva 12 uros.novak@ki.si 1000, Ljubljana, Slovenia E-mail: anja.verbic@ki.si +386 1 2003 230 Blaž Likozar barbara.golja@ntf.uni-lj,si Department of Catalysis and Chemical Reaction Engineering Department of Catalysis National Institute of Chemistry and Chemical Reaction Engineering Hajdrihova 19, National Institute of Chemistry 1000 Ljubljana, Slovenia Hajdrihova 19 blaz.likozar@ki.si 1000 Ljubljana, Slovenia barbara.golja@ki.si Blaž Stres Department of Catalysis and Chemical Reaction Engineering National Institute of Chemistry Hajdrihova 19, 1000 Ljubljana, Slovenia blaz.stres@ki.si 129 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION SUSTAINABLE FLAME RETARDANT SOLUTIONS: TUNING AMMONIUM PHYTATE CONCENTRATION FOR SILK COATINGS Maja Blagojevič1, Barbara Simončič1, Ivan Jerman2, Ana Drinčić2 1 and Brigita Tomšič 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2 National Institute of Chemistry Slovenia, Slovenia Abstract: A novel green flame retardant, ammonium phytate (APA), was synthesised and applied in various concentrations to silk fabrics to optimise flame resistance while maintaining the physical and mechanical properties of the fabric. Its performance was compared to the well-known green flame retardant phytic acid (PA). Both PA and APA were applied in concentrations ranging from 1 % to 20 % (in 5 % increments) using the pad-dry-cure method. Flame retardancy was determined by vertical flammability tests, while flexural rigidity, air permeability, breaking strength and elongation at break were evaluated to determine the effects of flame retardants on the physical and mechanical properties of the fabric. The results showed that APA exhibited superior flame retardant effect compared to PA. Concentrations above 5 % ensured effective protection without excessive stiffness and mechanical degradation, making APA a promising alternative for environmentally friendly flame retardant textile applications. Keywords: silk, green flame retardant, ammonium phytate, phytic acid, vertical flammability test, mechanical properties 1. INTRODUCTION Silk, a natural and biodegradable fibre, is valued for its luxurious texture and sustainability, making it useful not only for apparel but also in various economic sectors as a high-end material. However, its inherent flammability limits its use in fields where fire safety is crucial, such as protective clothing, home textiles, and the preservation of historical fabrics, as its combustion can not only cause material damage but also pose a risk to human safety (Zhang, 2024). Enhancing the flame retardancy of silk fibres is therefore essential. In the past, halogen-based flame retardants were the most commonly used due to their exceptional efficiency in inhibiting combustion. However, further research has shown that the combustion of such materials produces toxic compounds, including dioxins, furans and other halogenated acids, which pose a serious risk to human health and contribute significantly to environmental pollution (Lu, 2002). Growing environmental awareness and stricter sustainability regulations in the industry have driven research into the development and application of safer and more sustainable flame retardants. As a result, new synthesis and application processes based on phospho-rus and nitrogen compounds have been developed to effectively inhibit combustion without generating harmful by-products (Alongi, 2014; Salmeia, 2016). Phosphorus and nitrogen based flame retardants of natural origin play a crucial role in the development of sus-tainable flame retardant finishes. Of these, phytic acid (PA), which occurs naturally in cereal grains, pulses and nuts, is particularly noteworthy. Due to its high phosphorus content, it has already been recognised as an effective flame retardant in the textile industry (Cheng, 2016; Cheng, 2023; Wu, 2024; Zhang, 2018). Its salt, ammonium phytate (APA), which is synthesised from phytic acid and urea, has an even greater flame retardant potential due to the synergistic interaction between phosphorus and nitrogen (Feng, 2017). This combination increases char formation and thermal stability, improving the overall efficiency in preventing combustion compared to PA alone (Feng, 2017; Cheng, 2022). 130 29–30 May 2025, Ljubljana, Slovenia While APA has already been used on cotton fibres, to the best of our knowledge, its efficacy on silk fibres has not yet been investigated. Therefore, this study aims to optimize the concentration of APA on silk fibres and evaluate its flame retardant effect in comparison to PA, potentially enhancing flame retardancy through the combined effect of phosphorus and nitrogen. 2. EXPERIMENTAL 2.1 Materials As a model textile substrate a 100 % degummed silk fabric with a weight of 65 g/m2 was used throughout the experiments. Phytic acid (PA) and urea were purchased from Sigma Aldrich. 2.2 Synthesis of ammonium phytate (APA) APA was synthesised in the laboratories of the National institute of Chemistry (Slovenia) according to the pro- cedure described by (Feng, 2017). Briefly, PA (7.723 mL, 0.015 mol) and urea (5.405 g, 0.09 mol) were mixed, stirred, and heated for 60 min at 110 °C and 15 min at 120 °C, yielding a light brown liquid. The product was freeze-dried, purified with ethanol, and APA was obtained as a brownish solid. 2.3 Flame retardant finishing of silk fabric The finishing of silk fabrics was carried out using the pad-dry-cure method. First, finishing baths were prepared with different concentrations of APA and PA in water, ranging from 1 % to 20 % (w/w) in 5 % increments. The fabric samples were immersed in the corresponding finishing solution, wrung out with a two-roll padder. This process was carried out twice to achieve a wet pick-up of 210 ± 5 %, and then the samples were dried in a laboratory dryer at 100 °C for 90 s. Based on the concentration of the flame retardant used, the samples were coded as SE_PAx or SE_APAx, where x is the percentage of PA or APA used. The untreated silk fabric was coded as SE_0. 2.4 Characterization The flammability of the silk samples analysed was tested on vertically suspended samples using the standard flammability test DIN 53906.The fabric samples (15 x 9 cm, warp direction) were exposed to a propane gas flame for 4 seconds. The after-flame and after-glow times were recorded, with three measurements taken per sample and the mean values were calculated. Tear length was determined by suspending a 50 g weight from one end of the sample while the opposite end was fixed. The tear length was calculated as the difference between the original length of the sample and the remaining untorn length. In order to determine the influence of the PA and APA coating on the mechanical-physical properties of the treated silk samples compared to the untreated sample, measurements of bending rigidity, breaking strength, elongation at break and air permeability were carried out. The flexural rigidity was determined in accordance with ASTM standard D-1388-64. The measurements of breaking strength and elongation at break were carried out using an Instron 5567 dynamometer according to the SIST ISO 5081:1996 standard method. For each silk sample, ten measurements were carried out in the warp direction at a tearing speed of 100 mm/min and a measuring length of 100 mm. The air permeability was measured with an Air-Tronic B (Mesdan, Italy) according to the SIST EN ISO 9237:1999 standard. 3. RESULTS AND DISCUSSION The results of flame retardant properties of silk fabrics functionalized with APA compared to PA at different con-centrations are summarised in Table 1 and Figure 1. Untreated silk burned vigorously and without residue, with after-flame and after-glow times of 7.0 s and 5.9 s, respectively. In contrast, the application of APA completely stopped the spread of flame and resulted in after-flame and after-glow times of 0 s, even at the lowest concentra-tion tested, which was comparable to the flame retardant effect of PA. 131 29–30 May 2025, Ljubljana, Slovenia However, when comparing the flame retardant effect of APA with that of PA at the same concentrations, APA ex-hibited significantly better results than PA. While the tear length of the SE_APA1 sample (1 % APA) was compa-rable to that of the SE_PA1 sample (1 % PA), increasing the APA concentration resulted in a 20–26 % reduction of the tear length compared to the corresponding PA samples. The reduced tear length clearly demonstrates the enhanced flame retardant effect of APA and thus the increased thermal stability of APA-functionalised silk sam-ples, which is attributed to the synergistic effect of phosphorus and nitrogen within the APA structure. In contrast, the flame retardant effect of PA is based solely on phosphorus, which means less intensive protection of the silk against thermal degradation. A char length of less than 150 mm is usually required for effective flame retardancy, with 100 mm being the pre-ferred threshold for high-performance flame retardant textiles (NFPA 701: Standard Methods of Fire Tests for Flame Propagation of Textiles and Films). The samples treated with APA at concentrations above 5 % not only inhibited combustion during flame removal, but also exhibited a significantly reduced tear length, ensuring com-pliance with this flame retardant standard. Table 1: After-flame (t ) and after-glow time (t ) of the studied samples and corresponding tear length after-flame after-glow (l ) determined according to the DIN 53906 standard method. tear Sample code Flame retardant C (%) t (s) t (s) l (cm) after-flame after-glow tear SE_0 / / 7.0 5.9 15.0 SE_PA1 1 0 0 10.5 SE_PA5 5 0 0 10.8 SE_PA10 PA 10 0 0 10.9 SE_PA15 15 0 0 9.9 SE_PA20 20 0 0 9.0 SE_APA1 1 0 0 10.9 SE_APA5 5 0 0 8.6 SE_APA10 APA 10 0 0 8.4 SE_APA15 15 0 0 7.9 SE_APA20 20 0 0 6.7 132 29–30 May 2025, Ljubljana, Slovenia Figure 1: Photos of untreated and PA- or APA-functionalised samples, showing the remaining residual char after the vertical flame spread test. When chemically modifying textiles, it is crucial to consider not only the functional performance, but also the effects on the intrinsic physical and mechanical properties. Therefore, handling properties (Figure 2), air permea-bility (Figure 3) and tensile properties (Figure 4) were evaluated. Figure 2 shows the results of stiffness, including areal density, bending length and total flexural rigidity. The areal density increased with higher concentrations of finishing agents, which was expected due to the increased dry content on the fibres (Figure 2a). Bending length increased for SE_PA5 and SE_APA5 samples, indicating ini-tial stiffening, but decreased at higher concentrations, although areal density continued to increase (Figure 2b). The highest stiffness was observed with SE_PA5 and SE_APA5, while SE_PA20 and SE_APA20 had the lowest bending lengths, similar to untreated silk (SE_0). The reason for this could be ascribed to the increase of areal density. However, PA-functionalised samples exhibited lower bending lengths than APA-treated samples despite higher areal density. Therefore, the main reason for the decrease in bending lengths, could be ascribed to the moisture-absorbing properties of PA. Namely, the silk samples functionalized with PA felt significantly more moist than the samples functionalized with APA. As moisture acts as a natural lubricant, this probably contributed to the lower bending length of the PA-treated samples. As a result, PA-functionalised samples exhibited lower overall flexural rigidity compared to APA-functionalised samples at the same flame retardant concentration (Figure 2c). 133 29–30 May 2025, Ljubljana, Slovenia Figure 2: Areal density (a) and bending length (b) of untreated (C = 0 %) and PA- or APA-functionalised samples over PA/APA the studied concentration range ( C = 1–20 %) and their corresponding flexural rigidity (c). PA/APA Figure 3 shows the results of air permeability for silk fabrics functionalized with PA and APA. The air permeability initially decreases at 1 % but gradually increases up to 10 %. Beyond that, at 15 % and 20 %, the trend became inconsistent, with differences between PA- and APA-treated samples. High standard deviations indicate con-siderable variability within the sample sets, probably due to the heterogeneous distribution of flame retardants leading to localised pore blockage. However, the untreated silk (SE_0) also exhibits high variability, suggesting that inherent irregularities in the fabric also contribute to the variations in air permeability. Consequently, this vari-ability limits the ability to draw firm conclusions about the exact influence of PA and APA at higher concentrations. Nevertheless, a general trend can be recognised which indicate that the air permeability tends to recover at higher concentrations compared to the initial drop at 1 %. The functionalisation of silk with studied flame retardants had different effects on the tensile properties of the silk fabric (Figure 4). While functionalisation with APA did not significantly affect either the breaking strength or the elongation at break, even at higher concentrations (> 10 %), the application of PA led to a significant deterioration of these properties. In fact, both breaking strength (Figure 4a) and elongation at break (Figure 4b) showed a de-creasing trend with increasing PA concentration, indicating a weakening effect of PA on the mechanical integrity of the silk fabric. One possible reason for this is the higher moisture absorption of PA compared to APA, which was observed during handling of the tested samples. This could have contributed to a softening effect that disturbed the hydrogen bonds within the silk fibroin network, leading to a decrease in cohesion between the silk protein chains, and thus a reduction in tensile properties. 134 29–30 May 2025, Ljubljana, Slovenia Figure 3: Air permeability (Q) of untreated (C = 0 %) and PA- or APA-functionalised samples over the studied concentration PA/APA range (C = 1–20 %). PA/APA Figure 4: Breaking strenght (F) (a) and elongation at break (ε) (b) of untreated (C = 0 %) and PA- or APA-functionalised PA/APA samples over the studied concentration range (C = 1–20 %). PA/APA 4. CONCLUSIONS The study shows that APA effectively improved the flame retardancy of silk, with showing superior performance compared to PA, due to the synergistic effect of phosphorus and nitrogen. The latter was demonstrated in a 20–26 % reduction in tear length after the vertical flammability test. While APA-functionalised fabrics maintained better mechanical integrity, PA weakened the fabric due to higher moisture absorption. Air permeability showed variability, likely due to the uneven distribution of the flame retardants as well as inherent irregularities in the fabric. To achieve optimal balance between flame retardancy and fabric integrity APA concentration of 5 % and higher is recommended, ensuring effective protection of silk from thermal degradation without excessive stiffness or mechanical degradation. Funding: This research was founded by the Slovenian Research and Innovation Agency (Programme P2-0213 Textiles and Ecology, Infrastructural Centre RIC UL-NTF). 135 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Zhang, Y., Xing, T., Huang, Z., He, A., Luo, Y., Hong, Y., Wang, M., Shi, Z., Tong, A., Qiao, S., Ke, G., Zhao, T., Chen, F. in Xu, W. An innovative strategy towards highly efficient flame-retardant silk. Chemical Engineering Journal, 2024, 489, 151356. Lu, S.-Y. in Hamerton, I. Recent developments in the chemistry of halogen-free flame retardant polymers. Progress in Polymer Science, 2002, 27, 1661–1712. Salmeia, K. A., Gaan, S. in Malucelli, G. Recent Advances for Flame Retardancy of Textiles Based on Phosphorus Chemistry. Polymers, 2016, 8, 319. Alongi, J., Carosio, F. in Malucelli, G. Current emerging techniques to impart flame retardancy to fabrics: An overview. Polymer Degradation and Stability, 2014, 106, 138-149. Feng, Y., Zhou, Y., Li, D., He, S., Zhang, F. in Zhang, G. A plant-based reactive ammonium phytate for use as a flame-retardant for cotton fabric. Carbohydrate Polymers, 2017, 175, 636–644. Cheng, X.-W., Song, J.-Y., Cui, M.-L., Dong, S. in Guan, J.-P. Reactive phytate-based intumescent flame-retardant toward sustainable and durable functional coating of silk fabric. Materials Today Sustainability, 2023, 24, 100528. Zhang, X., Zhou, X.-Y., Cheng, X.-W. in Tang, R.-C. Phytic acid as an eco-friendly flame retardant for silk/wool blend: A comparative study with fluorotitanate and fluorozirconate. Journal of Cleaner Production, 2018, 198, 1044-1052. Wu, C., Lu, L.-X., Wu, Z.-X., Cheng, X.-W. in Guan, J.-P. Fully biobased approach for sustainable flame retardancy, antibacterial and anti-UV modification of silk fabric. Industrial Crops & Products, 2024, 222, 119557. Cheng, X.-W., Guan, J.-P., Tang, R.-C. in Liu, K.-Q. Phytic acid as a bio-based phosphorus flame retardant for poly(lactic acid) nonwoven fabric. Journal of Cleaner Production, 2016, 124, 114-119. Cheng, X.-W., Wang, Z.-Y., Jin, W.-J. in Guan, J.-P. Covalent flame-retardant functionalization of wool fabric using ammonium phytate with improved washing durability. Industrial Crops & Products, 2022, 187, 115332. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Brigita Tomšič Maja Blagojevič Ivan Jerman Faculty of Natural Sciences Faculty of Natural Sciences Hajdrihova 19 and Engineering 1000 Ljubljana, Slovenia University of Ljubljana University of Ljubljana National Institute of Chemistry and Engineering Aškerčeva cesta 12 Ivan.jerman@ki.si Aškerčeva cesta 12 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia mb23671@student.uni-lj.si Ana Drinčić National Institute of Chemistry brigita.tomsic@ntf.uni-lj.si Barbara Simončič Hajdrihova 19 University of Ljubljana 1000 Ljubljana, Slovenia Faculty of Natural Sciences ana.drincic@ki.si and Engineering Aškerčeva cesta 12 1000, Ljubljana, Slovenia barbara.simoncic@ntf.uni-lj.si 136 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION KOMBUCHA-EXTRACT-MEDIATED GREEN SYNTHESIS OF SILVER NANOPARTICLES FOR ANTIBACTERIAL SILK TEXTILES Nika Pirš1, Barbara Simončič1, Rok Fink2 and Brigita Tomšič1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2University of Ljubljana, Faculty of Health Sciences, Slovenia Abstract: In this study, Kombucha extract was introduced as a green reducing and stabilising agent for the in situ biosynthesis of silver nanoparticles (Ag NPs) on silk fabric. The silk fabric was first treated with a 2.0 mM AgNO₃ aqueous solution, followed by treatment with Kombucha extract for 1, 2 and 4 hours at 35 °C. UV-Vis spectros-copy confirmed the successful formation of the Ag NPs by detecting characteristic SPR peaks. Regardless of the synthesis time, the functionalized samples showed significant antimicrobial activity against Escherichia coli and Staphylococcus aureus without the formation of a distinctive inhibition zone, indicating minimal diffusion of the na-noparticles. The findings highlight the feasibility of Kombucha-mediated Ag NPs functionalization for sustainable development of antimicrobial silk textiles. Keywords: silk, green in situ biosynthesis, silver nanoparticles, Kombucha extract, antimicrobial activity 1. INTRODUCTION The antimicrobial functionalisation of textiles is crucial, not only to prevent the growth of microorganisms responsi-ble for unpleasant odours and to maintain personal hygiene, but above all to protect against pathogenic microor-ganisms (Morais, 2016; Windler, 2013). Due to their large surface area and ability to retain moisture, textile fibres provide an ideal environment for colonisation by microorganisms and pose a potential risk for the transmission of bacteria, fungi and viruses from person to person (Balasubramaniam, 2020). Studies on nosocomial pathogens indicate that various bacterial, fungal and viral species can persist for weeks on natural and synthetic textile sur-faces, making contaminated textiles a potential vector for infection transmission (Kampf, 2020). Silver nanoparticles (Ag NPs) are among the most commonly used antimicrobial agents for textile applications due to their broad spectrum of activity. However, the conventional synthesis of Ag NPs often uses toxic chemicals and produces hazardous by-products, leading to concerns about risks to the environment and human health. In response, biosynthesis methods have emerged as a sustainable alternative, utilising biological entities such as plant extracts, microorganisms and biomolecules to reduce silver ions (Ag ⁺) into metallic nanoparticles. Com-pared to conventional synthesis methods, biosynthesis offers advantages such as lower toxicity, cost efficiency and improved biocompatibility, making it particularly attractive for biomedical and textile applications (Radetić, 2013; Rai, 2009; Simončič, 2017). Kombucha extract, a product of tea fermentation rich in polyphenols, organic acids and microbial metabolites (Abaci, 2022; Jayabalan, 2014) has recently been explored as a reducing and stabilising agent for the synthe-sis of Ag NPs, which demonstrated excellent antibacterial activity against S. aureus and E. coli (Shanmugavel, 2017). The bioactive compounds in Kombucha facilitate the formation of nanoparticles while influencing their size, morphology and stability. By optimising synthesis parameters such as pH, temperature and reaction time, the an-timicrobial efficacy and functional properties of Ag-NPs synthesised from Kombucha can be improved (El-Fallal, 2023). However, to the best of our knowledge, previous studies have focused exclusively on ex situ synthesis, and the direct in situ synthesis of Ag NPs on textile substrates has not yet been explored . This study aims to develop a green in situ Ag NPs synthesis approach for the antimicrobial functionalisation of textiles using Kombucha extract as a natural reducing agent. The antimicrobial efficacy of the synthesised Ag NPs 137 29–30 May 2025, Ljubljana, Slovenia will be systematically evaluated on silk fabrics, thus contributing to the development of sustainable antimicrobial 29–30 May 2025, Ljubljana, Slovenia textile materials. 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL 2.1 Materials NPs will be systematically evaluated on silk fabrics, thus contributing to the development of sustainable antimicrobial textile materials. NPs will be systematically evaluated on silk fabrics, thus contributing to the development of sustainable Throughout the experiments, a 100% degummed silk fabric with a weight of 65 g/m 2 was used. Silver nitrate antimicrobial textile materials. (AgNO 2. EXPERIMENTAL ) was purchased from Sigma Aldrich. Kombucha SCOBY (Symbiotic colony of bacteria and yeasts) starting 3 culture was purchased by a local producer Fermentarnica d.o.o. (Slovenia). 2.1 Materials 2. EXPERIMENTAL 2.2 Preparation of kombucha extract Throughout the experiments, a 100% degummed silk fabric with a weight of 65 g/m2 was used. Silver nitrate 2.1 Materials (AgNO 3 ) was purchased from Sigma Aldrich. Kombucha SCOBY (Symbiotic colony of bacteria and yeasts) Throughout the experiments, a 100% degummed silk fabric with a weight of 65 g/m 2 was used. Silver nitrate starting culture was purchased by a local producer Fermentarnica d.o.o. (Slovenia). The Kombucha SCOBY sample was activated accordingly. A growth medium of black tea (5 g/L) and sucrose (80 (AgNO 3 ) was purchased from Sigma Aldrich. Kombucha SCOBY (Symbiotic colony of bacteria and yeasts) g/L) was prepared by boiling for 5 minutes and then allowed to cool to room temperature. Subsequently, 900 ml of starting culture was purchased by a local producer Fermentarnica d.o.o. (Slovenia). 2.2 Preparation of kombucha extract the tea broth was inoculated with Kombucha pellicle fragments (3.7 % w/v, wet weight basis) and 10 % (v/v) liquid broth of the activated tea fungus. The mixture was incubated for 14 days under dark, static conditions at room The Kombucha SCOBY sample was activated accordingly. A growth medium of black tea (5 g/L) and sucrose 2.2 Preparation of kombucha extract and other solid residues. The Kombucha SCOBY sample was activated accordingly. A growth medium of black tea (5 g/L) and sucrose 900 ml of the tea broth was inoculated with Kombucha pellicle fragments (3.7 % w/v, wet weight basis) and 10 (80 g/L) was prepared by boiling for 5 minutes and then allowed to cool to room temperature. Subsequently, temperature. After the incubation period, the Kombucha biomass extract was filtered to remove microbial spores (80 g/L) was prepared by boiling for 5 minutes and then allowed to cool to room temperature. Subsequently, 900 ml of the tea broth was inoculated with Kombucha pellicle fragments (3.7 % w/v, wet weight basis) and 10 conditions at room temperature. After the incubation period, the Kombucha biomass extra % (v/v) liquid broth of the activated tea fungus. The mixture was incubated for 14 days under dark, static ct was filtered to 2.3 In situ synthesis of Ag NPs % (v/v) liquid broth of the activated tea fungus. The mixture was incubated for 14 days under dark, static remove microbial spores and other solid residues. The silk samples were immersed in a 2.0 mM aqueous solution of AgNO₃ at a fabric-to-liquid ratio of 1:25 and remove microbial spores and other solid residues. conditions at room temperature. After the incubation period, the Kombucha biomass extract was filtered to stirred for 10 minutes at 30 °C using the Starlet-2 DL-6000 Plus infrared dyeing device (DaeLim Starlet Co., Ltd., 2.3 In situ synthesis of Ag NPs Korea) to ensure uniform dispersion and adsorption of Ag The silk samples were immersed in a 2.0 mM aqueous solution of AgNO ⁺ ions on the silk fibres. The Kombucha extract was ₃ at a fabric-to-liquid ratio of 1:25 and 2.3 In situ synthesis of Ag NPs slightly alkalized with 1 M NaOH before being gradually added to the AgNO stirred for 10 minutes at 30 °C using the Starlet-2 DL-6000 Plus infrared dyeing device (DaeLim Starlet Co., ₃ solution containing the silk samples, The silk samples were immersed in a 2.0 mM aqueous solution of AgNO ₃ at a fabric-to-liquid ratio of 1:25 and with the final fabric-to-liquid ratio adjusted to 1:50. The samples were then stirred at 30 °C for a further 1, 2 or 4 Ltd., Korea) to ensure uniform dispersion and adsorption of Ag ⁺ ions on the silk fibres. The Kombucha extract stirred for 10 minutes at 30 °C using the Starlet-2 DL-6000 Plus infrared dyeing device (DaeLim Starlet Co., hours, rinsed thoroughly with distilled water and air-dried at room temperature. Based on the synthesis time the was slightly alkalized with 1 M NaOH before being gradually added to the AgNO ₃ solution containing the silk Ltd., Korea) to ensure uniform dispersion and adsorption of Ag ⁺ ions on the silk fibres. The Kombucha extract samples were coded as SE_Ag-1, SE_Ag-2 and SE_Ag-4. samples, with the final fabric-to-liquid ratio adjusted to 1:50. The samples were then stirred at 30 °C for a was slightly alkalized with 1 M NaOH before being gradually added to the AgNO ₃ solution containing the silk further 1, 2 or 4 hours , rinsed thoroughly with distilled water and air-dried at room temperature. Based on the samples, with the final fabric-to-liquid ratio adjusted to 1:50. The samples were then stirred at 30 °C for a synthesis time the samples were coded as SE_Ag-1, SE_Ag-2 and SE_Ag-4. further 1, 2 or 4 hours , rinsed thoroughly with distilled water and air-dried at room temperature. Based on the 2.4 Characterization synthesis time the samples were coded as SE_Ag-1, SE_Ag-2 and SE_Ag-4. 2.4 Characterization The surface morphology of the studied samples was studied by scanning electron microscope (SEM) JSM-6060 LV (Jeol, Japan). The surface morphology of the studied samples was studied by scanning electron microscope (SEM) JSM-2.4 Characterization 6060 LV (Jeol, Japan). The reflectance and transmittance of the studied samples was recorded in a 250–780 nm wavelength range using The surface morphology of the studied samples was studied by scanning electron microscope (SEM) JSM-The reflectance and transmittance of the studied samples was recorded in a 250 – 780 nm wavelength range a Lambda 800+ UV/Vis spectrophotometer (Perkin Elmer, Great Britain). From the reflectance (R) values of the 6060 LV (Jeol, Japan). using a Lambda 800+ UV/Vis spectrophotometer (Perkin Elmer, Great Britain). From the reflectance (R) values samples obtained at different wavelengths, the colour strength (K/S) was calculated as follows: The reflectance and transmittance of the studied samples was recorded in a 250 – 780 nm wavelength range of the samples obtained at different wavelengths, the colour strength (K/S) was calculated as follows: using a Lambda 800+ UV/Vis spectrophotometer (Perkin Elmer, Great Britain). From the reflectance (R) values of the samples obtained at different wavelengths, the colour strength (K/S) was calculated as follows: 2 K ( 1−R ) � = (1) S 2R 2 K ( 1−R ) � = (1) From the transmittance values UV protection factor (UPF) was determined according to the S 2R Standard EN From the transmittance values UV protection factor (UPF) was determined according to the Standard EN 13758-13758-1:2001. 1:2001. From the transmittance values UV protection factor (UPF) was determined according to the Standard EN The antibacterial activity of the analysed samples was determined by evaluating the dehydrogenase enzyme 13758-1:2001. The antibacterial activity of the analysed samples was determined by evaluating the dehydrogenase enzyme ac activity using iodonitrotetrazolium chloride (INT) for Escherichia coli ATCC 35218 and Staphylococcus aureus-The antibacterial activity of the analysed samples was determined by evaluating the dehydrogenase enzyme tivity using iodonitrotetrazolium chloride (INT) for ATCC 29213. A bacterial suspension with a concentration of 1 × 10 6 CFU/ml was applied to the samples in a Escherichia coli ATCC 35218 and Staphylococcus aureus ATCC activity using iodonitrotetrazolium chloride (INT) for Escherichia coli microtitre plate and then incubated at 37°C for 24 hours. After incubation, the samples were washed with 2 mL 29213. A bacterial suspension with a concentration of 1 × 10 6 ATCC 35218 and Staphylococcus aureus CFU/ml was applied to the samples in a microtitre ATCC 29213. A bacterial suspension with a concentration of 1 × 10 6 CFU/ml was applied to the samples in a of 0.9% NaCl to remove non-adherent bacteria. Subsequently, 0.5 mL of a 0.5 mg/mL INT solution was added, plate and then incubated at 37°C for 24 hours. After incubation, the samples were washed with 2 mL of 0.9% microtitre plate and then incubated at 37°C for 24 hours. After incubation, the samples were washed with 2 mL and the plate was incubated at 37°C for 2 hours to allow INT reduction. To dissolve the formed formazan, 0.5 NaCl to remove non-adherent bacteria. Subsequently, 0.5 mL of a 0.5 mg/mL INT solution was added, and the of 0.9% NaCl to remove non-adherent bacteria. Subsequently, 0.5 mL of a 0.5 mg/mL INT solution was added, mL of DMSO (dimethyl sulfoxide) was added and the optical density (OD) was measured at 490 nm. Based plate was incubated at 37°C for 2 hours to allow INT reduction. To dissolve the formed formazan, 0.5 mL of DMSO and the plate was incubated at 37°C for 2 hours to allow INT reduction. To dissolve the formed formazan, 0.5 on the OD values, the antibacterial activity (AA ) of the studied samples was determined as follows: (dimethyl sulfoxide) was added and the optical density (OD) was measured at 490 nm. Based on the OD values, mL of DMSO (dimethyl sulfoxide) was added and the optical density (OD) was measured at 490 nm. Based the antibacterial activity (AA) of the studied samples was determined as follows: on the OD values, the antibacterial activity (AA ( 𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂 𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈 ) of the studied samples was determined as follows: −𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂 𝐹𝐹𝐹𝐹 ) AA = × 100 [%] (2) 𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂 𝐹𝐹𝐹𝐹 AA = (𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈−𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝐹𝐹𝐹𝐹) × 100 [%] (2) where OD 𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂 UN is the OD at 490 nm determined for the untreated silk sample and OD 𝐹𝐹𝐹𝐹F is the OD at 490 nm determined for the functionalised silk sample. where ODUN is the OD at 490 nm determined for the untreated silk sample and ODF is the OD at 490 nm determined for the functionalised silk sample. In addition, the leaching properties of the functionalized samples were assessed by evaluating the zone of In addition, the leaching properties of the functionalized samples were assessed by evaluating the zone of 138 inhibition using the Kirby-Bauer method. A 0.1 mL suspension of the tested bacterial species at a concentration inhibition using the Kirby-Bauer method. A 0.1 mL suspension of the tested bacterial species at a concentration 2 29–30 May 2025, Ljubljana, Slovenia where OD is the OD at 490 nm determined for the untreated silk sample and OD is the OD at 490 nm determined UN F for the functionalised silk sample. In addition, the leaching properties of the functionalized samples were assessed by evaluating the zone of inhibition using the Kirby-Bauer method. A 0.1 mL suspension of the tested bacterial species at a concentration of 1.5 × 10⁸ CFU/mL was evenly distributed on Tryptic Soy Agar (TSA) plates. A disc-shaped sample was then placed on each plate and incubated at 37°C for 24 hours, after which the zone of inhibition was measured. 3. RESULTS AND DISCUSSION The in situ synthesis of Ag NPs by Kombucha extract led to notable changes in the surface morphology of the silk fibres. As can be seen in the SEM images in Figure 1, the untreated silk fibres have a smooth and cylindrical structure. In contrast, after functionalisation with Ag NPs, thin, ribbon-like structures were loosely attached to the fibre surface regardless of the synthesis time. However, no clear deposition of nanoparticles on the fibre surfaces can be seen at the magnification applied. Figure 1: SEM images of silk samples at 3000x magnification showing morphological differences before and after the in situ synthesis of Ag NPs. UV-Vis spectroscopy was used to confirm the presence of Ag NPs on the surface of silk fibres, as it is one of the most commonly used techniques to characterise Ag NPs by surface plasmon resonance (SPR). The UV-Vis absorption spectra of the colloidal Ag NPs solutions obtained after removal of the silk samples (Figure 2a) show two broad absorption bands: the first centred at around 360 nm and the second at 440 nm. The presence of these distinct SPR peaks indicates the formation of spherical Ag-NPs, as reported in previous studies (Laouini, 2021). The band at 360 nm can be attributed to smaller nanoparticles, while the broader peak at 440 nm indicates the presence of larger nanoparticles or their aggregation. Increasing the synthesis time resulted in a slight increase in 440 nm peak intensity while maintaining its position, indicating that the morphology of Ag NPs in the colloidal solution was not affected by the synthesis duration. 139 29–30 May 2025, Ljubljana, Slovenia Figure 2: UV-Vis absorption spectra of Kombucha extract and colloidal Ag solutions after treatment of silk samples (a) and colour strength (K/S) spectra of silk samples treated with Kombucha extract (SE_K) and functionalized with in situ synthesised Ag NPs(b). The colour strength (K/S) spectra (Figure 2b) of the sample treated with Kombucha extract (SE_K) showed two intense absorption peaks at 280 nm and 360 nm, which can be attributed to polyphenolic compounds and other metabolites in the extract. After the in situ synthesis of Ag NPs, a significant decrease in the intensity of both peaks was observed in the K/S spectra of samples SE_Ag-1, SE_Ag-2 and SE_Ag-4. This decrease clearly indicates the consumption of the compounds responsible for the reduction during the formation of the nanoparticles and confirms the role of the extract as a reducing agent. Furthermore, a shift of the peak from 360 nm to 372 nm was clearly observed after the synthesis of the Ag nanoparticles. Such a shift is typically associated with the formation of silver nanoparticle aggregates or the SPR effect, which can cause changes in the absorption bands depending on the size and aggregation of the nanoparticles. Interestingly, the spectral changes were not significantly influ-enced by the synthesis time, suggesting that the duration of synthesis does not play a crucial role in the optical properties of the resulting Ag NPs. Next, the self-sterilising performance of the silk fabric samples tested was evaluated and the results are shown in Figure 3. After 24 hours of contact with the Gramme-negative E. coli and Gramme-positive S. aureus bacteria, the Ag NPs on the functionalised silk fibres significantly reduced the enzyme activity of dehydrogenase, resulting in a sharp decrease in the optical density (OD) of the INT indicator. This reduction led to a remarkable antibacterial activity with a growth inhibition of about 80% for E. coli and about 69% for S. aureus. The slightly lower activity against S. aureus can be attributed to the structural differences in the cell membranes between Gramme-nega-tive and Gramme-positive bacteria. However, a gradual increase in antibacterial activity against S. aureus was observed with longer synthesis time. Figure 3: Optical density (OD) at 490 nm indicating the dehydrogenase enzyme activity on the surface of the studied samples after inoculation with E. coli or S. aureus bacteria (a), and corresponding antibacterial activity (AA) of the samples (b). 140 29–30 May 2025, Ljubljana, Slovenia To assess the leaching properties of the biosynthesised Ag NPs, a qualitative evaluation was performed using the Kirby-Bauer method (Figure 4). Regardless of the synthesis time, none of the tested samples exhibited an inhibi-tion zone, indicating that the concentration of Ag NPs was not sufficient to effectively inhibit bacterial growth of E. coli or S. aureus by diffusion-based mechanisms. These results are promising as they demonstrate the potential of Kombucha-mediated Ag NP functionalisation for the development of silk-based antimicrobial textiles while mi-nimising unintended effects on beneficial skin microflora. Figure 4: Growth of E. coli (a) and S. aureus (b) on the agar plates according to Kirby-Bauer method. 4. CONCLUSIONS The use of Kombucha extract enabled the successful in situ biosynthesis of Ag NPs as confirmed by UV-Vis spectroscopy. The results showed characteristic SPR peaks indicative of nanoparticle formation, with spectral shifts in the K/S spectra further demonstrating the role of the extract as a reducing agent. Antibacterial tests showed significant self-sterilising properties of the functionalized silk, with growth inhibition of up to 80% against E. coli and 69% against S. aureus, with a slight increase in efficacy against S. aureus with longer synthesis time. In addition, no significant leaching of Ag-NPs was observed, indicating a minimal Ag concentration in the immediate environment of the functionalized samples. These results underline the potential of Kombucha extract-synthesised Ag NPs for the sustainable development of antimicrobial silk textiles. Funding: This research was founded by the Slovenian Research and Innovation Agency (Programme P2-0213 Textiles and Ecology, Infrastructural Centre RIC UL-NTF). 5. REFERENCES Abaci, N., Senol Deniz, F.S., and Orhan, I.E. 2022.Kombucha – An Ancient Fermented Beverage with Desired Bioactivities: A Narrowed Review. Food Chem X 14: 100302. Balasubramaniam, B., Prateek, Ranjan, S., Saraf, M., Kar, P., Singh, S.P., Thakur, V.K., Singh, A. and Gupta, R.A. 2020. Antibacterial and antiviral functional materials: Chemistry and biological activity toward tackling COVID-19-like pandemics. ACS Pharmacology & Translational Science 4 (1): 8–54. El-Fallal, A.A., Elfayoumy, R.A., and El-Zahed, M.M. 2023. Antibacterial activity of biosynthesized zinc oxide nanoparticles using Kombucha extract. SN Applied Sciences 5 (12): 332. Jayabalan, R., Malbaša, R.V., Lončar, E.S., Vitas, J.S., and Sathishkumar, M. 2014. A review on Kombucha Tea—Microbiology, composition, fermentation, beneficial effects, toxicity, and tea fungus. Comprehensive Reviews in Food Science and Food Safety 13 (6): 538–550. Kampf, G. 2020. How long can nosocomial pathogens survive on textiles? A systematic review. GMS Hygiene and Infection Control 15: Doc10. Laouini, S.E., Bouafia, A., Soldatov, A.V., Algarni, H., Tedjani, M.L., Ali, G.A.M., and Barhoum, A. 2021. Green synthesized Ag/Ag₂O nanoparticles using aqueous leaves extracts of Phoenix Dactylifera L. and their azo dye photodegradation. Membranes 11 (7): 468. Morais, D.S., Guedes, R.M., and Lopes, M.A. 2016. Antimicrobial approaches for textiles: From research to market. Materials 9 (7): 498. Rai, M., Yadav, A., and Gade, A. 2009. Silver nanoparticles as a new generation of antimicrobials. Biotechnology Advances 27 (1): 76–83. 141 29–30 May 2025, Ljubljana, Slovenia Radetić, M. 2013. Functionalization of textile materials with silver nanoparticles. 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ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Brigita Tomšič Nika Pirš Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering University of Ljubljana University of Ljubljana Aškerčeva cesta 12 Aškerčeva cesta 12 1000, Ljubljana 1000, Ljubljana np65501@student.uni-lj.si brigita.tomsic@ntf.uni-lj.si Barbara Simončič University of Ljubljana Faculty of Natural Sciences and Engineering Aškerčeva cesta 12 1000, Ljubljana barbara.simoncic@ntf.uni-lj.si Rok Fink University of Ljubljana Faculty of Health Sciences Zdravstvena pot 5 1000, Ljubljana rok.fink@zf.uni-lj.si 142 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION FUNCTIONALIZATION OF SILK WITH GREEN CHITOSANꟷALOE VERAꟷESSENTIAL OIL COMPOSITE FOR MEDICAL APPLICATION Laura Cimperman1, Barbara Simončič1, Rok Fink2 and Brigita Tomšič1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2University of Ljubljana, Faculty of Health Sciences, Slovenia Abstract: This study combines chitosan, aloe vera (AV) and citronella essential oil (EO) to functionalise silk fab-rics for advanced medical textile applications. A chitosan-AV-EO mixture was applied to the fabric together with β-cyclodextrin (β-CD) via the pad dry cure method. Scanning electron microscopy (SEM) was used to analyse the morphology of the fabric, while moisture content, antibacterial activity and leaching properties were evaluated to determine functional performance. The results demonstrate the potential of this composite for wound healing ap-plications, as it exhibits improved moisture retention and effective antibacterial activity against Gramme-negative bacteria. Further optimisation of AV and EO concentrations is required to improve efficacy against Gramme-pos-itive bacteria. The incorporation of β-CD helped to limit the leaching of AV and EO, potentially prolonging antimi-crobial activity and minimising cytotoxicity. Keywords: silk, medical textile, chitosan-based composite, moisture content, antibacterial activity 1. INTRODUCTION A wound is defined as any disruption of the continuity of the skin and underlying tissue that impairs the protective function of the skin and exposes deeper structures to mechanical damage, desiccation, radiation, thermal influ-ences and microbial contamination (Rajendran, 2011). Wounds can result from trauma, pathological conditions or surgical procedures, making effective treatment a crucial aspect of medical care. Wound treatment has evolved considerably in the past, from traditional methods such as cotton gauze and sa-line to modern wound dressings. Conventional dressings are often unable to effectively regulate moisture and pH, which can delay healing. In contrast, modern materials are designed to better retain moisture, maintain pH balance and optimise gas exchange, creating a more favourable healing environment. Moreover, the use of biocompatible materials and bioactive compounds is crucial to promote tissue regeneration and infection control (Rajendran, 2011). Chitosan-based hydrogels are considered one of the most promising materials for wound dressings due to their biocompatibility, biodegradability and remarkable antimicrobial and antioxidant properties. These advantages are due to the presence of hydroxyl (-OH) and amino (-NH ) groups in the chitosan molecular structure, which can do-2 nate electrons to neutralise free radicals (Hong, 2024). The antimicrobial activity of chitosan is primarily attributed to the protonation of the amino groups in acidic pH environments (below pH 6.5). This allows chitosan to interact with the negatively charged surfaces of microbial cell membranes, disrupting their integrity and ultimately causing cell death (Simončič, 2017). In addition, chitosan-based hydrogels can be easily modified to incorporate various bioactive agents such as aloe vera extract and essential oils (Amaral, 2024; Milanesi, 2021). These two natural antimicrobial substances further enhance the antimicrobial and antioxidant properties of chitosan. Essential oils from citrus fruits, for example, which are rich in limonene and flavonoids, contribute to the antibacterial, antiox-idant and anti-inflammatory effect, while aloe vera extract moisturises, soothes the skin and has an anti-inflam-matory effect. In addition, aloe vera stimulates collagen production and promotes the proliferation of fibroblasts, which supports tissue regeneration during wound healing (Ishfaq, 2021; Liang, 2021; Maduna, 2023). 143 29–30 May 2025, Ljubljana, Slovenia Driven by a sustainable approach to improve the quality of biomaterials while minimising the environmental im-pact, this study focused on the integration of chitosan, aloe vera extract and citronella essential oil to develop advanced medical textiles with enhanced antimicrobial, antioxidant and wound healing properties. By combining these bioactive components, the aim was to create a functional textile material that promotes an optimal healing 29–30 May 2025, Ljubljana, Slovenia environment, supports tissue regeneration and provides a biocompatible, environmentally friendly alternative for wound treatment. 2. EXPERIMENTAL combining these bioactive components, the aim was to create a functional textile material that promotes an 2.1 Materials friendly alternative for wound treatment. optimal healing environment, supports tissue regeneration and provides a biocompatible, environmentally viscosity: 159 mPa∙s) was sourced from Chitoclear, Primex (Iceland). Butanetetracarboxylic acid (BTCA, 99%) 2. EXPERIMENTAL Degummed 100% silk fabric (65 g/m²) was selected as the base material. Chitosan (degree of deacetylation: 95%, was used as a chitosan crosslinker, while sodium hypophosphite (SHP) served as the crosslinking initiator, both 2.1 Materials Aloe Degummed 100% silk fabric (65 g/m²) was selected as the base material. Chitosan (degree of deacetylation: obtained from Sigma-Aldrich (USA). To maintain an acidic pH, glacial acetic acid (Sigma-Aldrich, USA) was used. Aldrich (USA). 99%) was used as a chitosan crosslinker, while sodium hypophosphite (SHP) served as the crosslinking initiator, both obtained from Sigma-Aldrich (USA). To maintain an acidic pH, glacial acetic acid (Sigma-Aldrich, USA) was used. Aloe essential oil (EO) and β-cyclodextrin (β-CD) for essential oil encapsulation were both purchased from Sigma-95%, viscosity: 159 mPa∙s) was sourced from Chitoclear, Primex (Iceland). Butanetetracarboxylic acid (BTCA, barbadensis leaf powder (AV) concentrate (200:1) was supplied by Natural Loti (Slovenia). Citronella Java 2.2 Preparation of the finishing bath (Slovenia). Citronella Java essential oil (EO) and β-cyclodextrin (β-CD) for essential oil encapsulation were both purchased from Sigma-Aldrich (USA). barbadensis leaf powder (AV) concentrate (200:1) was supplied by Natural Loti A 1% chitosan solution was prepared by dissolving chitosan in water with the addition of 1% glacial acetic acid and magnetic stirring overnight. Subsequently, 2% BTCA and 2% SHP were gradually added to the chitosan solution 2.2 Preparation of the finishing bath chitosan/AV solution to obtain the final chitosan/AV/EO formulation. Prior to addition, β-CD and EO were finely and magnetic stirring overnight. Subsequently, 2% BTCA and 2% SHP were gradually added to the chitosan solution and stirred until completely dis solved. Before the finishing process, 0.4% aloe vera (AV) powder was ground using a mortar and pestle to facilitate encapsulation of the EO in the β-CD cavity. dissolved in the chitosan solution. In addition, a mixture of 0.33% β-CD and 0.33% essential oil (EO) was added to the chitosan/AV solution to obtain the final chitosan/AV/EO formulation. in the chitosan solution. In addition, a mixture of 0.33% β-CD and 0.33% essential oil (EO) was added to the A 1% chitosan solution was prepared by dissolving chitosan in water with the addition of 1% glacial acetic acid and stirred until completely dissolved. Before the finishing process, 0.4% aloe vera (AV) powder was dissolved Prior to addition, β-CD and 2.3 Functionalisation of the silk fabric EO were finely ground using a mortar and pestle to facilitate encapsulation of the EO in the β-CD cavity. The functionalisation of silk fabric was carried out using the pad-dry-cure method. The silk fabric samples were 2.3 Functionalisation of the silk fabric and cured at 150 °C for 5 minutes (sample code: SE_Ch+AV+EO). For comparison, a chitosan/AV solution and immersed in the chitosan/AV/EO solution at room temperature for 1 minute and then passed through a double roller padder to achieve a wet pick-u p of 120 ± 5%. The treated samples were then dried at 100 °C for 1 minute only chitosan were applied to the samples under the same conditions, resulting in samples SE_Ch+AV and and cured at 150 °C for 5 minutes (sample code: SE_Ch+AV+EO). For comparison, a chitosan/AV solution SE_Ch, respectively. roller padder to achieve a wet pick-up of 120 ± 5%. The treated samples were then dried at 100 °C for 1 minute The functionalisation of silk fabric was carried out using the pad-dry-cure method. The silk fabric samples were immersed in the chitosan/AV/EO solution at room temperature for 1 minute and then passed through a double and only chitosan were applied to the samples under the same conditions, resulting in samples SE_Ch+AV and SE_Ch, respectively. 2.4 Characterization 2.4 Characterization LV (Jeol, Japan). The surface morphology of the studied samples was studied by scanning electron microscope (SEM) JSM-The surface morphology of the studied samples was studied by scanning electron microscope (SEM) JSM-6060 6060 LV (Jeol, Japan). Moisture content (MC) was measured according to AATCC Test Method 20A-2008 Fibre Analysis: Quantitative. Moisture content (MC) was measured according to AATCC Test Method 20A-2008 Fibre Analysis: Quantitative. A moisture analyser MLB-C (Kern & SOHN GmbH, Germany) was used for this purpose. The samples were pre A moisture analyser MLB-C (Kern & SOHN GmbH, Germany) was used for this purpose. The samples were -conditioned for 24 hours at 65 ± 2% relative humidity at 20 °C and 40 °C before measurement. They were then preconditioned for 24 hours at 65 ± 2% relative humidity at 20 °C and 40 °C before measurement. They were placed in the moisture analyser and dried at 100 °C until a constant mass was achieved. MC was calculated using then placed in the moisture analyser and dried at 100 °C until a constant mass was achieved. MC was the following equation calculated using the following equation 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 𝑚𝑚𝑚𝑚0−𝑚𝑚𝑚𝑚𝑓𝑓𝑓𝑓 = �� × 100 [%], (1) 𝑚𝑚𝑚𝑚0 where m0 represents the initial mass of the pre-conditioned sample and mf the final mass of the sample after where m represents the initial mass of the pre-conditioned sample and m the final mass of the sample after drying. The 0 MC values were given as the average of five independent measurements. Based on the f MC values determined, the contribution to moisture content (C ) was calculated using the equation: MC 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 𝐹𝐹𝐹𝐹 −𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈 𝑀𝑀𝑀𝑀 drying. The determined, the contribution to moisture content (C MC values were given as the average of five independent measurements. Based on the MC ) was calculated using the equation:MC values 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 = � � × 100[%] (2) 𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈 where MCF is the moisture content of the functionalised samples, and MCUN is the moisture content of the untreated sample, determined under the same conditions. The antibacterial activity of the studied samples was evaluated by measuring the dehydrogenase enzyme 144 activity using iodonitrotetrazolium chloride (INT) against Escherichia coli ATCC 35218 (E. coli) and 6 Staphylococcus aureus ATCC 29213 ( S. aureus ) . A bacterial suspension with a concentration of 1×10 CFU/ml calculated using the following equation 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 𝑚𝑚𝑚𝑚0−𝑚𝑚𝑚𝑚𝑓𝑓𝑓𝑓 = �� × 100 [%], (1) 𝑚𝑚𝑚𝑚0 29–30 May 2025, Ljubljana, Slovenia where m0 represents the initial mass of the pre-conditioned sample and mf the final mass of the sample after drying. The MC values were given as the average of five independent measurements. Based on the MC values determined, the contribution to moisture content (CMC) was calculated using the equation: 𝑀𝑀𝑀𝑀 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝐹𝐹𝐹𝐹−𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 = � � × 100[%] ( 𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈 2) where where MCF is the moisture content of the functionalised samples, and MCUN is the moisture content of the MC is the moisture content of the functionalised samples, and MC is the moisture content of the untreat-untreated sample, determined under the same conditions. F UN 29–30 May 2025, Ljubljana, Slovenia ed sample, determined under the same conditions. using iodonitrotetrazolium chloride (INT) against activity using iodonitrotetrazolium chloride (INT) against Escherichia coli ATCC 35218 (E. coli) and Escherichia coli ATCC 35218 (E. coli) and Staphylococcus au-Staphylococcus aureus The antibacterial activity of the studied samples was evaluated by measuring the dehydrogenase enzyme activity The antibacterial activity of the studied samples was evaluated by measuring the dehydrogenase enzyme reus ATCC 29213 (S. aureus). A bacterial suspension with a concentration of 1×106 CFU/ml ATCC 29213 ( S. aureus ). A bacterial suspension with a concentration of 1×10 6 CFU/ml was applied to the and the plate was incubated for a further 2 hours at 37 °C to facilitate INT reduction. To dissolve the resulting for l INT solution was added and the plate was incubated for a further 2 hours at 37 °C to facilitate INT 2-reduction. To dissolve the resulting formazan, 0.5 mL of dimethyl sul foxide (DMSO) was added, and the optical mazan, 0.5 mL of dimethyl sulfoxide (DMSO) was added, and the optical density (OD) was measured at 490 nm. density (OD) was measured at 490 nm. The antibacterial activity (A) of the functionalized samples was The antibacterial activity (A) of the functionalized samples was calculated using the following equation: calculated using the following equation: mL of 0.9% NaCl to remove non-adherent bacteria. Subsequently, 0.5 mL of a 0.5 mg/ml INT solution was added samples were rinsed with 2 mL of 0.9% NaCl to remove non-adherent bacteria. Subsequently, 0.5 mL of a 0.5 mg/m samples in a microtiter plate and incubated at 37 °C for 24 hours. After incubation, the samples were rinsed with 2 was applied to the samples in a microtiter plate and incubated at 37 °C for 24 hours. After incubation, the A = (𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑈𝑈𝑈𝑈𝑈𝑈𝑈𝑈−𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝐹𝐹𝐹𝐹) × 100 [%] (3) 𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝑂𝐹𝐹𝐹𝐹 where OD where OD is the OD at 490 nm determined for the untreated silk sample and OD UN is the OD at 490 nm determined for the untreated silk sample and OD is the OD at 490 nm deter F is the OD at 490 nm-UN F mined for the functionalised silk sample. determined for the functionalised silk sample. To assess the potential release of antimicrobial agents from the functionalized samples, the zone of inhibition was determined using the Kirby-Bauer disk diffusion method. A 0.1 mL bacterial suspension (1.5×1081.5 \times 10^81.5×108 CFU/mL) of the tested species was eve To assess the potential release of antimicrobial agents from the functionalized samples, the zone of inhibition was determined using the Kirby-Bauer disk diffusion method. A 0.1 mL bacterial suspension (1.5×1081.5 \times shaped fabric sample was placed on each plate, followed by incubation at 37 °C for 24 hours. The antimicrobial nly spread onto Tryptic Soy Agar (TSA) plates. A disc- 10^81.5×108 CFU/mL) of the tested species was evenly spread onto Tryptic Soy Agar (TSA) plates. A disc-efficacy was then evaluated by measuring the diameter of the inhibition zone surrounding the sample. shaped fabric sample was placed on each plate, followed by incubation at 37 °C for 24 hours. The antimicrobial efficacy was then evaluated by measuring the diameter of the inhibition zone surrounding the sample. 3. RESULTS AND DISCUSSION Figure 1 shows the SEM images of the studied samples. The application of chitosan and chitosan– AV had no Figure 1 shows the SEM images of the studied samples. The application of chitosan and chitosan SE_Ch+AV samples show a smooth, cylindrical structure comparable to that of the untreated SE fibres, – AV had no sig-indicating that the functionalisation process preserved the original fibre integrity. In contrast, the SEM images 3. RESULTS AND DISCUSSION significant effect on the morphology of the silk fibres. The SEM images of the corresponding SE_Ch and nificant effect on the morphology of the silk fibres. The SEM images of the corresponding SE_Ch and SE_Ch+AV of SE_Ch+AV+EO show the presence of small surface deposits on the silk fibres, which can be attributed to samples show a smooth, cylindrical structure comparable to that of the untreated SE fibres, indicating that the the formation of the EO /β-CD complex. This implies a successful encapsulation of the EO within the β-CD functionalisation process preserved the original fibre integrity. In contrast, the SEM images of SE_Ch+AV+EO cavities, possibly contributing to the functional properties of the treated textile. show the presence of small surface deposits on the silk fibres, which can be attributed to the formation of the EO-/β-CD complex. This implies a successful encapsulation of the EO within the β-CD cavities, possibly contributing to the functional properties of the treated textile. Figure 1: SEM images of the studied silk samples obtained at 1000x magnification. Compared to untreated silk fabric (SE), the application of chitosan significantly increased the moisture content 145 ( MC ), with further increase observed by the addition of AV extract (Figure 3a). The presence of EO in the chitosan–AV composite had no further effect on MC, suggesting that it was successfully encapsulated without altering the moisture properties of the SE_Ch+AV sample. A more detailed analysis of the contribution of the 29–30 May 2025, Ljubljana, Slovenia Figure 1: SEM images of the studied silk samples obtained at 1000x magnification. Compared to untreated silk fabric (SE), the application of chitosan significantly increased the moisture content (MC), with further increase observed by the addition of AV extract (Figure 3a). The presence of EO in the chi-tosan–AV composite had no further effect on MC, suggesting that it was successfully encapsulated without alter-ing the moisture properties of the SE_Ch+AV sample. A more detailed analysis of the contribution of the bioactive components to the MC (C ) is shown in Figure 3b. The incorporation of chitosan resulted in a 28% increase in MC C , while the addition of AV and EO increased C by a further 10–12%. These results confirm the positive mois-MC MC turising effect of AV in combination with chitosan, independent of the presence of EO. Figure 2: Moisture content (MC) of the studied silk samples (a) and corresponding contribution of the bioactive components to the MC (C ) of the silk fibres (b) MC In addition to its moisturizing effect, the application of bioactive components imparted certain antibacterial activity against both model bacteria, E. coli and S. aureus. The SE_Ch sample exhibited good 76 % antibacterial activ-ity against E. coli, which was further slightly enhanced by the addition of AV and EO bioactive components. In contrast, only a moderate antibacterial effect was observed against S. aureus, with a 50 % reduction in bacterial growth. This difference can be attributed to structural variations in the cell membranes of Gram-negative and Gram-positive bacteria. Therefore, further optimization of the concentration of bioactive components is necessary to enhance antibacterial efficacy against Gram-positive bacteria. 146 29–30 May 2025, Ljubljana, Slovenia Figure 3: Optical density (OD) of the iodonitrotetrazolium chloride solution at 490 nm reflecting the activity of the enzyme dehydrogenase on the sample surfaces after inoculation with E. coli or S. aureus (a) and the corresponding antibacterial activity (R) (b). The leaching properties of AV and EO from the functionalized SE_Ch+AV and SE_Ch+AV+EO samples were in-vestigated using the Kirby-Bauer method against E. coli (Figure 4). Notably, only the SE_Ch+AV sample showed a minimal inhibition zone of 1.0–2.0 mm, indicating a controlled release of AV from the chitosan matrix. This release was suppressed when the EO/β-CD complex was introduced, confirming the successful encapsulation of EO in the hydrophobic interior of the β-CD. In addition, the hydrophilic exterior of the β-CD likely served as an anchoring site for AV, which also limited its leaching. Such controlled release behaviour is beneficial for wound healing as it may prolong antimicrobial activity while minimising potential cytotoxicity to surrounding healthy tissue. Figure 4: Evaluation of bioactive component release from studied samples using the Kirby-Bauer method against E. coli: (a) Inhibition zones, (b) Enlarged view of the inhibition zone for SE_Ch+AV, and (c) Absence of an inhibition zone for SE_ Ch+AV+EO. 4. CONCLUSIONS Functionalisation of the silk fibres with chitosan, AV and EO preserved the original fibre morphology, with only the SE_Ch+AV+EO sample showing small surface deposits, confirming the successful encapsulation of EO in β-CD. Chitosan significantly increased the moisture content, which was further enhanced by AV, while the addition of EO did not affect the achieved moistening effect. The treated fibres showed good antibacterial activity against E. coli, while the effect against S. aureus remained moderate. The limited diffusion of AV and EO from the β-CD complex suggests a controlled release, possibly prolonging antimicrobial activity while minimising cytotoxicity. Future research should focus on optimising AV and EO concentrations in the studied composite to improve antibacterial efficacy against both bacterial strains. 147 29–30 May 2025, Ljubljana, Slovenia Funding: This research was founded by the Slovenian Research and Innovation Agency (Programme P2-0213 Textiles and Ecology, Infrastructural Centre RIC UL-NTF). 5. REFERENCES Amaral, V. A., Santana, V. L., Lisboa, E. S., Martins, F. S., Chaud, M. V., de Albuquerque-Júnior, R. L. C., Santana, W., Santos, C., Santos, A. de J., Cardoso, J. C., Souto, E. B., and Severino, P. 2024. “Chitosan Membranes Incorporating Aloe Vera Glycolic Extract with Joint Synthesis of Silver Nanoparticles for the Treatment of Skin Lesions.” Drug Delivery and Translational Research. https://doi.org/10.1007/ s13346-024-01683-x. Hong, F., Qiu, P., Wang, Y., Ren, P., Liu, J., Zhao, J., and Gou, D. 2024. “Chitosan-Based Hydrogels: From Preparation to Applications, a Review.” Food Chemistry: X 21: 101095. Ishfaq, M., Akhtar, B., Muhammad, F., Sharif, A., Akhtar, M. F., Hamid, I., Sohail, K., and Muhammad, H. 2021. “Antioxidant and Wound Healing Potential of Essential Oil from Citrus reticulata Peel and Its Chemical Characterization.” Current Pharmaceutical Biotechnology 22 (8): 1114–1121. Liang, J.H., Cui, L.L., Li, J.K., Guan, S.M., Zhang, K. and Li, J.A. 2021. “Aloe Vera: A Medicinal Plant Used in Skin Wound Healing.” Tissue Engineering Part B: Reviews 27 (5): 455–474. Maduna, L. and Patnaik, A. 2023. “A Review of Wound Dressings Treated with Aloe Vera and Its Application on Natural Fabrics.” Journal of Natural Fibers 20 (1): 2190190. Milanesi, G., Vigani, B., Rossi, S., Sandri, G., and Mele, E. 2021. “Chitosan-Coated Poly(lactic acid) Nanofibres Loaded with Essential Oils for Wound Healing.” Polymers 13 (16): 2582. Rajendran, S. R., and Anand, S. C. 2011. “Hi-Tech Textiles for Interactive Wound Therapies.” In Handbook of Medical Textiles, edited by V. T. Bartels, 38–79. Cambridge: Woodhead Publishing Limited. Simončič, B., and Tomšič, B. 2017. “Recent concepts of antimicrobial textile finishes.” In Textile Finishing: Recent Developments and Future Trends, edited by K.L. Mittal and T. Bahners, 1–68. Beverly: Scrivener Publishing. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): University of Ljubljana University of Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences Brigita Tomšič Laura Cimperman and Engineering and Engineering Aškerčeva cesta 12 Aškerčeva cesta 12 1000, Ljubljana lc29797@student.uni-lj.si 1000, Ljubljana brigita.tomsic@ntf.uni-lj.si Barbara Simončič University of Ljubljana Faculty of Natural Sciences and Engineering Aškerčeva cesta 12 1000, Ljubljana barbara.simoncic@ntf.uni-lj.si Rok Fink University of Ljubljana Faculty of Health Sciences Zdravstvena pot 5 1000, Ljubljana rok.fink@zf.uni-lj.si 148 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION APPLICATION OF INCLUSION COMPLEXES Β-CYCLODEXTRIN-CITRUS ESSENTIAL OIL IN THE PRINTING PROCEDURE ON COTTON FABRIC Sandra Flinčec Grgac1, Daria Katinić1, Ana Sutlović1 and Ana Palčić1 1University of Zagreb, Faculty of Textile Technology, Croatia Abstract: The paper investigated the possibility of creating inclusion complexes β-cyclodextrin lemon essential oil and their application by means of textile printing processes on 100% cellulose fabrics in plain weave. After textile printing, half of the samples were subjected to a washing process according to EN ISO 6330:2012 with a detergent without the addition of optical brighteners to determine the durability of the print and the binding of the inclusion complexes of β-cyclodextrin and lemon essential oil to the material. The physico-chemical and mor-phological properties of the samples were analyzed using the following analytical methods: Fourier Transform Infrared Spectrophotometry (FTIR) and Scanning Electron Microscopy (FE-SEM). In addition to the above, in order to tentatively establish the binding of inclusion complexes of β-cyclodextrin and essential lemon oil to cotton cellulose using printing paste, a subjective method for olfactometric determination of the intensity of odor release in a certain period of time was also used. Based on the results obtained, it can be seen that the inclusion com-plexes β-cyclodextrin and lemon essential oil are successfully bound to cellulose material by printing method. The application of the finished textile product is intended to serve as protection against mosquitoes and other insects, so printing with the addition of inclusion complexes β-cyclodextrin and essential lemon oil could be used on bed linen and interior decorative fabrics. Keywords: inclusion complex β-cyclodextrin-essential oil, cotton fabric, textile printing, Fourier transform infrared spectrometry (FTIR), Scanning Electron Microscopy (FE-SEM) 1. INTRODUCTION Cotton is the most commonly used natural fiber in the world and is very reactive due to its molecular structure, as there are -OH groups at one end of the polymer chain, while an aldehyde group -CHO is present at the other end of the chain. The cellulose ring has a saddle-shaped structure, and in such a structure the bonds between the atoms are the least strained and this shape is the most energetically favorable, and given the position of the cellulose rings, the -OH groups are in the equatorial plane (Andrassy 2005). With the accelerated progress and development of technology, new textile materials are being developed that can be used in various areas of interest and improve the quality of life. One of the most important areas of research in the last decade has been the use of cyclodextrins and essential oils due to their non-toxicity and biodegradability. These unique properties enable a wide range of applications in the textile industry, especially in the field of textile processing, where their applica-tion to textiles aims to achieve certain functional properties such as odor absorption, UV protection, antimicrobial protection, insect protection, release of fragrance or active ingredients for skin care and the like (Knittel 2000, Szejtli 2003, Voncina 2013). Cyclodextrins (CD) are cyclic oligosaccharides with a specific hollow truncated cone structure that enables them to form inclusion complexes with hydrophobic molecules. In inclusion complexes, the cavity of the cyclodextrin molecule acts as a “host” and the complexing hydrophobic molecule as a “guest”. The dimensions of the “guest” molecule or one of its parts must be compatible with the dimensions of the cyclodextrin cavity in order for the complex to form. Cyclodextrin consists of glucopyranose units linked together by α-1,4-gly-cosidic bonds. Most commonly used in industry are α-, β- and γ-CD, which consist of 6, 7 and 8 glucose units (Eastburn 1994, Martin del Valle 2004, Voncina 2013). Of particular importance are the applications of β-cyclo-dextrin, which is often used in combination with various textile materials and chemical agents to bind active ingre-dients. The binding of cyclodextrin to cotton material can be achieved in various ways by cross-linking cyclodextrin with cotton, wool and polyester and polyamide fibers using polycarboxylic acids (1,2,3,4-butanetetracarboxylic 149 29–30 May 2025, Ljubljana, Slovenia acid (BTCA), citric acid (CA) and others) as well as aggressive or harmful chemicals such as cyanuric chloride to modify cyclodextrin or epichlorohydrin as cross-linking agents (Voncina 2013). Research found that cyclodextrin covalently bound to cellulose retains the ability to form complexes and the complexed active ingredient is released after contact with the skin (Haji 2020). The use of cyclodextrin in textile printing brings new possibilities for impro-ving the quality, sustainability and functionality of textile products. As water-soluble molecules, cyclodextrins have the ability to form inclusion complexes with pigments, which significantly increases their fixation on textile fibers and thus improves the wash and light resistance of the print (Cie 2015, Elgammal 2016, Wan 2016). These pro-perties not only contribute to an increase in color strength and resistance print , but also enable the development of functional textile products that release odors in a controlled manner under the influence of heat or moisture, for example. Research in the field of textile printing is still limited, but has recently intensified. In 1996, Knittel and colleagues investigated the use of cyclodextrin derivatives as a substitute for urea (Knittel 1996). Further research has shown that a monochlorotriazinyl derivative of β-cyclodextrin improves dye fixation on a blend of wool and polyester fabrics, and its effects on rheological properties, colour strength and fastness have been investigated (Erkan 2018, Hebeish 2006). Ibrahim et al. have focused their research on the pre-modification of the wool com-ponent in fabrics made from a blend of wool and polyester using monochlorotriazinyl-β-cyclodextrin. For printing on textiles, they used disperse dyes complexed with β-cyclodextrin, which achieved highly efficient printing with excellent UV protection properties and a significant improvement in print fastness properties (Ibrahim 2009). More recent research has focused on the use of cyclodextrin in environmentally friendly printing processes. Zhao et al. found, for example, that the modification of cotton fabrics with β-cyclodextrin during printing improves the adsorption of natural dyes, resulting in more intense shades and better color fastness. The mechanical proper-ties of the processed materials are significantly improved, with greater crease resistance being achieved (Zhao 2017). Further development and research in this area could lead to innovative solutions that meet the increasing demands for sustainability and functionality of textile products. Therefore, this paper represents one of the inno-vative approaches for the application of essential oils, such as citrus oil, which forms an inclusion complex with β-cyclodextrin bound to cotton. This technology allows the textile materials to gradually and continuously release fragrances and active ingredients, adding value to the product. The aim of this work is to investigate the potential of using cyclodextrins and essential oils in textile processing, with a focus on achieving favorable functional pro-perties of the material and the environmental benefits that this approach brings. 2. EXPERIMENTAL In this work, textile printing was carried out on 100% cotton fabric, with a surface weight of 150 g/m², a warp to weft ratio of 36/27 [ASTM D3775-07] and a yarn count of 60/2; 34/1 Nm. The print paste contained β-cyclodextrin (CycloLab R&D Ltd.) and lemon essential oil (ELEMENTS), a synthetic thickener (Printperfect 226 EC) and natu-ral pomegranate pigment (Sutlović 2020). The printing process was conducted by manual screen-printing, using the following tools: a manual lab-type flat screen-printing table, a wooden-handled polyurethane blade squeegee of 60 durometer hardness, and an aluminium 40 × 50 cm screen with a mesh of 62 threads/cm2. Considering that the applied method was hand screen-printing, the squeegee angle was kept between 7-10°, with optimal pressure to assure uniform transfer of the printing paste to the surface of a textile substrate. The printed samples were then dried and fixed in a laboratory stretch dryer (Benz) at a temperature of 150 ºC for 6 minutes. Table 1 shows the composition of the prepared printing pastes and the legend of the cotton sample labels used. 150 29–30 May 2025, Ljubljana, Slovenia Table 1. Presentation of the composition of the prepared printing pastes and the legend of the sample labels PRINTING PASTE 1 PRINITING PASTE 2 30 g synthetic thickener 30 g synthetic thickener 4 mL pigment so- 5 mL pigment solution: 100 mL soft water, 10 g β-cyclodex- lution: 100 mL soft trin, 25 mL lemon essential oil water, 1 g pomeg- ranate pigment 4 mL pigment solution: 100 mL soft water, 10 g β-cyclo- dextrin, 25 mL lemon essential oil, 1 g pomegranate pig- ment 3 μl lemon essential oil SAMPLE LABEL CDfree Samples printed with paste 1 CD2 Samples printed with paste 2 Cdfree_1xHLWD Paste 1 was used to print the sample CD2_1xHLWD Paste 2 was used to print the sample and the sample was subjected to one and the sample was subjected to one wash cycle. wash cycle. After printing, a wash cycle was carried out in accordance with standard EN ISO 6330:2012 [ISO 6330:2012] using a detergent without the addition of optical brighteners at a ratio of 1:20 to test the durability of the print on cellulose material. Physico-chemical changes in cotton samples were investigated using Fourier transform infrared spectroscopy in the attenuated total reflectance technique (FTIR-ATR) (Perkin Elmer, Spectrum 100 software). Four scans with a resolution of 4 cm-1 between 4000 cm-1 and 380 cm-1 were performed for each sample, and the spectra obtained were processed using the Spectrum 100 software package, Perkin Elmer. The samples were scanned with a high-resolution scanning electron microscope (FE-SEM), Tescan, MIRA\\LMU, Czech Republic, at different magnifications to examine the morphological surface characteristics and to confirm the bonding of the β-cyclodex-trin particles to the cellulose material. Prior to scanning, all samples were coated with a gold-palladium mixture in an SC7620 Sputter Coater Emitech Steamer. The rate of discharge from the inclusive complexes was measured subjectively by periodically testing the sample scent intensity. The samples were individually packed in plastic bags and left there for 7 days. They were tested by an 8-member committee, which rated the samples with an odour intensity of 1 to 5 (1 – no odour; 5 – intense odour). After the first day of testing, the samples were left strictly separated outdoors at room temperature. The tests were repeated after 3, 8 and 10 days. 3. RESULTS WITH DISCUSSION Figure 1 shows the morphological characterization of the surface of the samples performed with a high-resolution scanning electron microscope (FE-SEM Tescan, MIRA\\LMU, Czech Republic). a) CDfree b) Cdfree_ c) CD2 d) CD2 1xHLWD 1xHLWD Figure 1. Morphological characterization of the sample surface using FE-SEM at a magnification of 1000x 151 29–30 May 2025, Ljubljana, Slovenia The surface morphology of the cotton sample printed with paste without β-cyclodextrin-essence oil inclusion complexes (Figure 1 a) and b)) clearly shows the presence of printing paste before (Cdfree) and after the wash cycle (Cdfree_ 1xHLWD). On the surface of the cellulose sample treated with printing paste 2 (CD2) (Figure 1 c) and d)), the presence of β-cyclodextrin-essence oil inclusion complexes before (CD2) and after the wash cycle (CD2_1xHLWD) is visible in addition to the printing paste, indicating their successful bonding. However, larger clusters of anglomerated particles of the inclusion complexes are visible on the CD2 sample, while the presence of inclusion complexes in the printing paste is visible after the wash cycle. This was also confirmed on a physico-chemical level by FTIR analysis of the samples using the ATR technique. Figures 2 and 3 show the spectral bands of the printed samples, which had an inclusion complex of β-cyclodextrin and essential oil in their structure with the addition of natural pomegranate pigment. From the obtained spectral curves, it can be clearly seen that the sample has prominent peaks at a wavenumber of 1660 cm-1, indicating the presence of alkenes (C=C), which are a component of lemon essential oil. Stronger peaks in the range 2874 cm-1 to 2931 cm-1, corresponding to the stretching and vibration of C-H, have been found and which belong to a series of alkanes in lemon essential oil (Schulz 2002) and are absent in the spectral bands of cotton, pomegranate crystals and beta-cyclodextrin (Grgac 2022). A sharp peak at 1729 cm-1 indicates the presence of vinyl hydrocar-29–30 May 2025, Ljubljana, Slovenia bons, which are also found in citrus essential oils. In addition to the aforementioned changes in the spectral bands of the printed samples compared to the bands of the lemon essential oil used, changes are visible due to the presence of β-CD, which has very similar peaks to cellulose and enhances the signal of individual groups in the cellulose itself. The influence of dyes on printed cotton materials is very difficult to analyze, but it can be assumed that the pomegranate dye has influenced the elongation and amplification of the signal in the range of 1259 cm-1 materials is very difficult to analyze, but it can be assumed that the pomegranate dye has influenced the to 1025 cm-1 resulting from stretching within the C-O groups of cellulose. elongation and amplification of the signal in the range of 1259 cm-1 to 1025 cm-1 resulting from stretching within the C-O groups of cellulose. Figure 2. Spectra of cotton samples, CD2, Figure 3. Spectrum of sample CD2 after pomegranate pigment, citrus essential oil (lemon maintenance cycle (CD2_1xHLWD) essential oil) recorded on an FTIR-ATR spectrometer Olfactometric determination of odor intensity on the first day of testing showed that the CDfree and CDfree Olfactometric determination of odor intensity on the first day of testing showed that the CDfree and CDfree _1xHLWD samples had no odor because they were not printed with a paste containing inclusion complexes of _1xHLWD samples had no odor because they were not printed with a paste containing inclusion complexes of β-cyclodextrin and lemon essential oil. The CD2 samples were rated 5 by all examinees on the first day, and β-cyclodextrin and lemon essential oil. The CD2 samples were rated 5 by all examinees on the first day, and the the same sample that was washed was rated 5 by 6 examinees and 4 by 2 examinees, indicating an intense same sample that was washed was rated 5 by 6 examinees and 4 by 2 examinees, indicating an intense odor. odor. The tests on the third day showed the greatest decrease in odor in the sample with an average rating of The tests on the third day showed the greatest decrease in odor in the sample with an average rating of 3.8 for 3.8 for the CD2 sample and 3.4 for the CD2_1xHLWD sample. After eight days in the air, the CD2_1xHLWD the CD2 sample and 3.4 for the CD2_1xHLWD sample. After eight days in the air, the CD2_1xHLWD samples had samples had a lower odor intensity (average value of 2.4) than the CD2 samples (average value of 3.1). After a lower odor intensity (average value of 2.4) than the CD2 samples (average value of 3.1). After the 10th day, the the 10th day, the samples washed after textile printing CD2_1xHLWD had a slightly lower odor intensity (with samples washed after textile printing CD2_1xHLWD had a slightly lower odor intensity (with an average value of an average value of 2.4) than the samples that were not washed with CD2 (with an average value of 2.8). 2.4) than the samples that were not washed with CD2 (with an average value of 2.8). Based on all the recorded Based on all the recorded results of the subjective odor evaluation, we can conclude that the odor of the CD2 results of the subjective odor evaluation, we can conclude that the odor of the CD2 samples is gradually released samples is gradually released over the course of 10 days, with the indication that it also remained present in over the course of 10 days, with the indication that it also remained present in the CD2_1xHLWD sample. This the CD2_1xHLWD sample. This method of olfactometric investigation is subjective and depends on various method of olfactometric investigation is subjective and depends on various parameters of the investigator, so the parameters of the investigator, so the results obtained only serve as possible guidelines for further results obtained only serve as possible guidelines for further development of such samples. development of such samples. 4. CONCLUSIONS In the middle of the last century, research was intensified to incorporate the principles of green chemistry into textile finishing processes, with the aim of achieving multifunctionality through the use of fabrics and processes that are considered biodegradable, non-toxic, environmentally friendly and economically acceptable. The development has not been smooth in the past and is still not smooth today, as a number of problems related to the stable bonding of various substances to textile substrates, which are mostly made of cellulose, occur on 152 a daily basis. The aim of this work was to obtain a multifunctional material printed with a printing paste with the addition of β-cyclodextrin inclusion complexes and citrus essential oil using pomegranate as a natural dye. The success of the printing method for the stable binding inclusion complexes β-cyclodextrin essential oil 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS In the middle of the last century, research was intensified to incorporate the principles of green chemistry into textile finishing processes, with the aim of achieving multifunctionality through the use of fabrics and processes that are considered biodegradable, non-toxic, environmentally friendly and economically acceptable. The devel-opment has not been smooth in the past and is still not smooth today, as a number of problems related to the stable bonding of various substances to textile substrates, which are mostly made of cellulose, occur on a daily basis. The aim of this work was to obtain a multifunctional material printed with a printing paste with the addition of β-cyclodextrin inclusion complexes and citrus essential oil using pomegranate as a natural dye. The success of the printing method for the stable binding inclusion complexes β-cyclodextrin essential oil lemon with cellulose was confirmed by characterising the surface morphology of the printed cellulose sample, where the presence of particles of the inclusion complexes of β-cyclodextrinand lemon essential oil is visible before and after the washing cycle. Physico-chemical changes of the printed samples with the addition of β-cyclodextrin-lemon essential oil inclusion complexes were monitored through the spectral bands obtained by recording the samples on an FTIR spectrometer in the ATR technique and clearly indicate the presence of a peak at the wave number 1660 cm-1, which indicates the existence of alkenes ( C=C), which are part of citrus essential oil. Stronger peaks were also recorded in the range of 2830 cm-1 to 2960 cm-1 corresponding to the stretching and vibration of C-H present in a series of alkanes in citrus essential oil. The olfactometric determination of the odor intensity showed that the odor remains in good intensity even after 10 days of aging of the samples, while the odor intensity decreases in the printed, washed sample, but is still present. Based on the results obtained, the success of binding the in-clusion complexes of β-cyclodextrin and lemon essential oil to the cellulose material by printing is evident, and the research conducted provided valuable insights for the further development of multifunctional durable textile finishing. 5. ACKNOWLEDGEMENT This work has been supported in part by Croatian Science Foundation under project UIP-2017-05-8780 HPRO-TEX and the short-term support of the University of Zagreb, Faculty of Textile Technology, entitled Functionaliza-tion and characterization of textiles and leather to achieve protective properties, TP/9. 6. REFERENCES Andrassy, M. and Čunko, R. 2005. Vlakna. Čakovec: ZRINSKI d. d. Cie, C. 2015. Ink jet textile printing. New York: Elsevier. Eastburn, S.D. and Tao, B.Y. 1994. „Applications of modified cyclodextrins.“ Biotechnol advances. 12 (2): 325–339. Elgammal, M., Schneider, R. and Gradzielski, M. 2016. „Development of self-curable hybrid pigment inks by miniemulsion polymerization for inkjet printing of cotton fabrics.“ Dyes and Pigments. 133: 467-478. Erkan, G., Sengül, K., Akkaş, M. and Büyükpoyraz, S. 2018. „Pigment printing of cotton fabrics with cyclodextrin and bifunctional reactive dye.“ Fascicle of textiles, Leatherwork. 19 (2): 43-48. Grgac, S.F., Jablan, J., Inić, S., Malinar, R., Kovaček, I., Čorak, I. 2022. „The Effect of Ultrasonic Treatment on the Binding of the Inclusion Complex β-Cyclodextrin-peppermint Oil with Cellulose Material.“ Materials. 15: 470. https://doi.org/10.3390/ma15020470 Haji, A. 2020. „Functional Finishing of Textiles with β-Cyclodextrin.“ In Frontiers of Textile Materials: Polymers, Nanomaterials, Enzymes, and Advanced Modification Techniques, edited by Mohd Shabbir, Shakeel Ahmed, Javed N. Sheikh, 87–116. Beverly, Massachusetts, USA: Scrivener Publishing LLC. Hebeish, A. A., Ragheb, A. A., Nassar, S. H., Allam, E. E. and El Thalouth, J. A. 2006. „Technological evaluation of reactive cyclodextrin in cotton printing with reactive and natural dyes.“ Journal of applied polymer science. 102 (1): 338-347. Ibrahim, N. A. and El-Zairy, E. M. R. 2009. „Union disperse printing and UV-protecting of wool/polyester blend using a reactive β-cyclodextrin.“ Carbohydrate Polymers. 76 (2): 244-249. Knittel, D. and Schollmeyer, E. 2000. „Technologies for a new century. Surface modification of fibres.“ Journal of the Textile Institute. 91 (3): 151-165. Knittel, D. and Schollmeyer, E. 1996. „Beitraege zum Reaktivdruck-Substitution von Harnstoff.“ Textilveredlung. 31: 153-156. Martin del Valle, E.M. 2004. „Cyclodextrins and their uses: a review.“ Process Biochemistry. 39 (9): 1033–1046. Szejtli, J. 2003. „Cyclodextrins in the Textile Industry.“ Starch/Stärke. 55 (5): 191-196. Voncina, B. and Vivod, V. 2013. Cyclodextrins in textile finishing. URL: https://www.intechopen.com/chapters/42001 (last accessed on 15. 01. 2025.). 153 29–30 May 2025, Ljubljana, Slovenia Wan, T., Chen, D. and Bai, X. 2016. „Preparation and relative properties of dope-dyed polyurethane modified by β-cyclodextrin.“ Dyes and Pigments. 129: 18-23. Zhao, C., Wang, C., Chen, K. and Yin, Y. 2017. „Improvement of ink-jet printing performances using β-cyclodextrin forming inclusion complex on cotton fabric.“ Fibers and Polymers. 18 (4): 619-624. Sutlović, A., Glogar, M. I., Bešlić, S., Brlek, I. 2020. Prirodna bojila za tekstil – doprinos kreativnosti i održivosti, Tekstil. 69 (1-3): 1-10, ISSN: 0492-5882 ISO 6330:2012(en) Textiles — Domestic washing and drying procedures for textile testing ASTM D3775-07, Standard Test Method for Warp (End) and Filling (Pick) Count of Woven Fabrics Schulz, H., Schrader, B., Quilitzsch, R. and Steuer, B. 2002. „Quantitative analysis of various citrus oils by ATR/FT-IR and NIR-FT Raman spectroscopy.“ Applied spectroscopy. 56 (1): 117-124. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Sandra Flinčec Grgac Daria Katinić (student) Faculty of Textile Technology Faculty of Textile Technology Prilaz baruna Filipovića 28a University of Zagreb University of Zagreb Department of Textile HR-10000 Zagreb, Croatia Chemistry and Ecology Student Prilaz baruna Filipovića 28a HR-10000 Zagreb, Croatia Ana Sutlović University of Zagreb +385 1 4877 355 Faculty of Textile Technology sflincec@ttf.unizg.hr Department of Textile Chemistry and Ecology Prilaz baruna Filipovića 28a HR-10000 Zagreb, Croatia +385 1 4877 354 ana.sutlovic@ttf.unizg.hr Ana Palčić University of Zagreb Faculty of Textile Technology Department of Textile Chemistry and Ecology Prilaz baruna Filipovića 28a HR-10000 Zagreb, Croatia +385 1 4877 350 ana.palcic@ttf.unizg.hr 154 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION FORMATION OF HALOCHROMIC POLYAMIDE/ELASTANE KNITTED FABRIC BY SCREEN PRINTING METHOD Mateja Kert1 and Špela Jerebic1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The possibility of designing a textile sensor that reacts to the pH value by changing its colour was studied in the research. The knitted fabric made of polyamide 6.6/elastane was screen-printed with the indicator dye bromophenol blue (BPB). The sensitivity of the knitted fabric to pH changes was evaluated spectrophotomet-rically by measuring the CIELAB colour values before and after immersing the printed samples in different buffer solutions, namely pH 2.2, 3, 4, 5, 6, 7, 9 and 11. At the same time, the pH sensitivity of the BPB dye in buffer solutions was also determined. The results showed that the designed halochromic knitted fabric is pH sensitive and the colour change is visible to the naked eye. The BPB dye in the printed samples reacts less strongly to the pH value than the BPB dye in buffer solutions. The halochromic effect of the printed sample is reversible, but the reversibility depends on the number of immersions in buffer solutions. Keywords: polyamide/elastane knitted fabric, halochromism, screen printing, bromophenol blue. 1. INTRODUCTION Continuous progress in science and technology is the key to the development of society. In the fields of medicine, health and hygiene, value-added textiles, including smart textiles and wearable technologies, represent an im-portant market segment. In recent years, there has been a great demand for human health monitoring (Sajovic, 2023). This is due to the health issues that people have faced in the last two decades due to the rapid develop-ment of the world, climate change and stressful working environments. Monitoring the spread of diseases that lead to more complicated and risky surgical interventions and cures is a less financially beneficial method than monitoring the health of middle-aged people. The letter could serve as a preventive measure for a healthier life in old age. For this reason, the development of chromic materials that respond to changes in the environment such as temperature, UV light and pH with a colour change is crucial as they have potential applications in health mon-itoring, environmental sensing and wearable technologies. Chromic materials are known as passive smart mate-rials. The colour change is usually reversible and visible to the naked eye (Bamfield, 2018). By applying chromic dyes or pigments to a textile substrate, a textile-based chromic sensor can be produced that can change colour in response to certain changes in the environment (Christie, 2013). Such a dye can change from a colourless to a coloured state, from a coloured to a colourless state or from one colour to another. Dyes that react to pH changes are called halochromic dyes, which also include the indicator dyes. The manufacture of disposable diapers for newborns and babies is primarily focused on high absorption of urine to keep children dry through day and night. As disposable diapers are a combination of different materials with dif-ferent functional properties, they all serve the same purpose, which is to provide high absorbency while ensuring comfort and dryness when worn (Brunning, 2020). Due to the moderate biodegradability of disposable diapers (Czarnecka, 2022) and people’s environmental awareness (Sachidhanandham, 2020), the use of cloth diapers is increasing year on year. There are disposable diapers on the market that already contain the indicator dye bromophenol blue (Brunning, 2020), which is marketed by manufacturers as an indicator dye for the wetness of the diaper with urine, but we have not seen the indicator dye in cloth diapers. Therefore, we focused our research on the formation of halochromic textiles by applying the halochromic dye bromophenol blue to knitted polyamide 6.6/elastane fabrics using a flat screen-printing process to develop a flexible textile sensor. If the colour of such a diaper changes, parents could be warned that the wet diaper should be replaced with a dry diaper. 155 29–30 May 2025, Ljubljana, Slovenia In the study, polyamide 6.6/elastane knitted fabric was screen-printed with the indicator dye bromophenol blue. The time required for the printed fabric to change colour after immersion in buffer solutions with different pH values was recorded. In addition, the reversibility of the colour change after repeated immersion of the printed samples in buffer solutions with a pH value of 2.2 and 7 was determined. 2. EXPERIMENTAL 2.1 Knitted fabric White knitted fabric made of 91 % polyamide 6.6 and 9 % elastane with a density of 20 wales/cm and 28 courses/ cm and mass per surface area of 200 g/m2 producer of Inplet pletiva, d.o.o., Sevnica, Slovenia. 2.1 Dye In the research indicator dye 3,’3”,5,’5”- Tetrabromophenol Sulfonephthalein or Bromophenol blue (BPB) with empirical formula of C H Br O S and molecular mass of 669.96 g/mol (Sigma-Aldrich, USA) was used. The 19 10 4 5 structural formula of the dye is presented in Figure 1. Figure 1: Bromophenol blue dye 2.2 Thickening agent and auxiliaries The following chemicals were used to produce the printing paste: thickening agent Prisulon DCA 130 (CHT, Switzerland), which is a polygalactomannan ether, urea (Acrosorganics, The Netherlands) which is a hydrotropic agent and increases the solubility of the dye, tiodiglycol Glyezyin A (BASF, Germany) to improve the solubility of the dye and ammonium sulphate (NH ) SO (Fluka, The Netherlands) which is responsible for the acidic medium 4 2 4 of the printing paste were used in the study. The McIlvain buffer system was used to prepare buffer solutions with a pH of 2.2, 3, 4, 5, 6 and 7, which required 0.2 M solution of disodium hydrogen phosphate (Na HPO ) and 0.1 2 4 M solution of citric acid (C H O ). Buffer solutions already prepared by Kefo, Slovenia, were used for pH 9 and 11. 6 8 7 2.3 Preparation of knitted fabric for printing The knitted fabric was soaped with 0.5 g/L non-ionic soaping agent Etolat OA138 (Orka, Ljubljana) in a Gorenje WA 844T household washing machine at 40 °C, using a washing programme for synthetics with a duration of 59 minutes and 800 rpm. After washing, two rinses were carried out at 30 °C for 20 minutes at 800 rpm. The washed knitwear was dried in the Gorenje D72GBL drying machine at a lower temperature using the drying programme for synthetics. 156 29–30 May 2025, Ljubljana, Slovenia 2.4 Preparation of the printing paste Printing paste was prepared according to the receipt written in Table 1. Table 1: Composition of the printing paste Ingredient 29–30 May 2025, Ljubljana, Slovenia Concentration (g/kg) dye BPB 3 urea 50 Table 1: H O, cold, distilled 57 2 Composition of the printing paste H O, boiling, disilled 280 2 Ingredient Concentration (g/kg) Glyezin A 50 dye BPB 3 Prisulon DCA 130 13% urea 500 50 H (NH 2 O, cold, distilled 57 ) SO 1 : 2 60 4 2 4 H 2 O, boiling, disilled 280 Glyezin A 50 2.1 Printing and aftertreatments Prisulon DCA 130 13% 500 (NH4)2 SO4 1 : 2 60 Samples of knitted fabric were printed with the use of electromagnetic laboratory printing machine Mini MFD R 390, (J. Zimmer, Austria) using the following parameters: diameter of the printing knife of 4 mm, speed of the print 2.1 Printing and aftertreatments - ing knife passes of 80%, degree of magnetic pressure of 3, number of printing knife passes of 2. The fabric sam-Samples of knitted fabric were printed with the use of electromagnetic laboratory printing machine Mini MFD ples were printed with a blank flat screen stencil, with a mesh size of 77 threads/cm. After printing, the samples R 390, (J. Zimmer, Austria) using the following parameters: diameter of the printing knife of 4 mm, speed of were dried at 100 °C for 1 minute and steaming normally for 20 min at 100–102 °C in a laboratory Ink jet textile the printing knife passes of 80%, degree of magnetic pressure of 3, number of printing knife passes of 2. The steamer. The wet fastness of the printed samples of PA6 was increased by cold reserving with 1.5 g/L Cibatex PA fabric samples were printed with a blank flat screen stencil, with a mesh size of 77 threads/cm. After printing, (Huntsman, Germany) at pH 3.5–4 with 60% CH COOH (Sigma Aldrich Chemie, Germany) for 10 min. Then the the samples were dried at 100 °C for 1 minute and steaming normally for 20 min at 100–102 °C in a laboratory 3 samples were rinsed with cold water, soaped with 1 g/L Tinegal W (Huntsman, Germany) for 15 min at 50 °C and Ink jet textile steamer. The wet fastness of the printed samples of PA6 was increased by cold reserving with rinsed with warm and then cold water at the end. The samples were then dried at 100 °C for 1 minute. 1.5 g/L Cibatex PA (Huntsman, Germany) at pH 3.5–4 with 60% CH 3 COOH (Sigma Aldrich Chemie, Germany) for 10 min. Then the samples were rinsed with cold water, soaped with 1 g/L Tinegal W (Huntsman, Germany) for 15 min at 50 °C and rinsed with warm and then cold water at the end. The samples were then dried at 100 2.2 Methods of testing °C for 1 minute. The colour of the printed samples was measured with a Datacolor Spectro 1050 (Datacolor, USA) spectrophoto Spectrophotometric measurements -The colour of the printed samples was measured with a Datacolor Spectro 1050 (Datacolor, USA) meter and CIELAB colour space. Measurements were made in the range 400–700 nm with a d/8° measurement Spectrophotometric measurements 2.2 Methods of testing geometry, under D illumination, 10° standard observer, with specular reflectance included with a 9-mm aperture. measurement geometry, under D spectrophotometer and CIELAB colour space. Measurements were made in the range 400–700 nm with a d/8° Four layers of the sample were used for the measurements. An average of 10 measurements was taken for each a 9-mm aperture. Four layers of the sample were used for the measurements. An average of 10 measurements 65 65 illumination, 10° standard observer, with specular reflectance included with sample. The CIELAB values were determined on unprinted and printed samples. The colour strength ( K/S) was was taken for each sample. The CIELAB values were determined on unprinted and printed samples. The calculated from the reflectance values according to the Kubelka-Munk equation (1): colour strength ( K/S ) was calculated from the reflectance values according to the Kubelka-Munk equation (1): K 2 (1-R) = (1) S 2R where where K is absorption coefficient, S is scattering coefficient and R is the reflectance factor. K is absorption coefficient, S is scattering coefficient and R is the reflectance factor. Determination of the pH sensitivity of the printed samples to the colour change Determination of the pH sensitivity of the printed samples to the colour change solutions with different pH values, namely 2.2, 3, 4, 5, 6, 7, 9 and 11. After 15 minutes, all samples were The colour response of the printed samples to pH was determined after the samples were immersed in buffer The colour response of the printed samples to pH was determined after the samples were immersed in buffer removed from the buffer solutions, air-dried and analysed spectrophotometrically by measuring CIELAB values and reflectance in the range of 400–700 nm. solutions with different pH values, namely 2.2, 3, 4, 5, 6, 7, 9 and 11. After 15 minutes, all samples were removed from the buffer solutions, air-dried and analysed spectrophotometrically by measuring CIELAB values and reflec-Determination of the pH sensitivity of the dye in buffer solutions tance in the range of 400–700 nm. A stock solution of BPB dye was prepared by dissolving 0.022 g of BPB in 10 ml of distilled water. 0.3 ml of the BPB solution was added to 20 ml of buffer solutions with different pH values and the absorbance spectrum of the BPB dye was recorded with the Lambda 850+ UV-Vis spectrophotometer (Perkin Elmer, GB) in the range of 400–700 nm. Determination of the reversibility of the pH-sensitive dye on printed samples Before the printed sample was immersed in the buffer solution, the CIELAB values of the sample were 157 measured. Five measurements were taken, and the result represents the average value. The sample was then immersed in a buffer solution with a pH value of 2.2, in which the strongest colour change was observed. The samples were left in the solution for 15 minutes and then allowed to air dry before the CIELAB values were 29–30 May 2025, Ljubljana, Slovenia Determination of the pH sensitivity of the dye in buffer solutions A stock solution of BPB dye was prepared by dissolving 0.022 g of BPB in 10 ml of distilled water. 0.3 ml of the BPB solution was added to 20 ml of buffer solutions with different pH values and the absorbance spectrum of the BPB dye was recorded with the Lambda 850+ UV-Vis spectrophotometer (Perkin Elmer, GB) in the range of 400–700 nm. Determination of the reversibility of the pH-sensitive dye on printed samples Before the printed sample was immersed in the buffer solution, the CIELAB values of the sample were measured. Five measurements were taken, and the result represents the average value. The sample was then immersed in a buffer solution with a pH value of 2.2, in which the strongest colour change was observed. The samples were left in the solution for 15 minutes and then allowed to air dry before the CIELAB values were measured. Five CIELAB readings were taken on the dry sample, and the result represents the average value. The same sample was then immersed in a pH 7 buffer for 15 minutes, air dried and the CIELAB values were measured again, taking 5 mea-surements of the CIELAB values. The process of immersing the printed sample in the pH 2.2 buffer and then in pH 7 buffer was repeated 9 times. 3. RESULTS AND DISCUSSION The CIELAB values of the printed samples before (S) and after immersion (S_pH) in buffer solutions with different pH values are summarised in Table 1. It can be seen from the values that the colour of the S_pH samples has changed compared to the S sample. While the CIE L* values of the S_pH samples do not change significantly compared to the S sample, the CIE a* values decrease sharply and become negative in buffers with pH 2.2, 3 and 4 and then become positive again as the pH value increases. This means that the samples turn green at lower pH values (from pH 2.2 to pH 4) or become less green and redder as the pH increases from pH 5 to pH 11. The CIE b* values of the S_pH sample become less negative after immersion in the buffers of pH 2.2, 3 and 4 and almost reach the CIE b* values of the S sample when the pH increases from pH 5 to pH 11. This means that the S_pH samples immersed in the buffers pH 2.2, 3, 4 and 5 become less blue and more yellow, but when the pH increas-es from 6 to 11, they become slightly bluer than the S sample. The chroma of the S_pH samples decreases after immersion in buffers of pH 2.2, 3, 4 and 5, indicating that the colour of the samples is less saturated, but increases again as the pH increases from 6 to 11, indicating that the colour of the samples is more saturated. The calculated colour difference (∆E* ) between the S and S_pH samples decreases with increasing pH from 2.2 to 11. This ab means that a pH-sensitive knitted fabric has been successfully designed. Since the highest colour difference ∆E*ab = 37.81) was achieved at the lowest pH value of 2.2, this means that the colour change is clearly visible even to the naked eye. The colour change of the printed samples after immersion in the buffer solutions was also visible to the naked eye in buffers with a pH value of 2.2 (∆ E* = 37.81) to pH 5 (∆E* = 2.22). The reversibility of the ab ab colour on samples printed with BPB dye is shown in Figure 2. Table 1: CIELAB colur values, chroma (C* ) and hue (h ) of the printed samples before (S) and after immer-ab ab sion (S_pH) in buffer solutions with different pH values Sample L* a* b* C*ab h (°) DE* abab S 58.27 1.83 -43.51 43.55 272.40 / S_pH 2.2 59.75 -11.86 -8.30 14.48 214.98 37.81 S_pH 3 58.02 -9.23 -20.38 22.37 245.62 25.64 S_pH 4 57.22 -3.44 -34.59 34.76 264.33 10.41 S_pH 5 57.05 0.68 -42.06 42.06 270.92 2.22 S_pH 6 57.34 2.15 -44.32 44.37 272.77 1.27 S_pH 7 57.21 2.50 -45.16 45.23 273.17 2.07 S_pH 9 57.48 2.41 -44.32 44.39 273.10 1.27 S_pH 11 57.77 2.17 -44.60 44.65 272.78 1.25 158 S_pH 4 57.22 -3.44 -34.59 34.76 264.33 10.41 S_pH 5 57.05 0.68 -42.06 42.06 270.92 2.22 S_pH 6 57.34 2.15 -44.32 44.37 272.77 1.27 29–30 May 2025, Ljubljana, Slovenia S_pH 7 57.21 2.50 -45.16 45.23 273.17 2.07 S_pH 9 57.48 2.41 -44.32 44.39 273.10 1.27 S_pH 11 57.77 2.17 -44.60 44.65 272.78 1.25 80 80 al al 20 v v 20 B B 0 0 ues ues 40 40 60 60 LA LA -20 IE IE-20-40 C C-40-60 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 Number of immersions Number of immersions Figure 2: Figure 2: Changes of CIELAB values before and after different number of immersions into buffer solution of pH 2.2 (left) and Changes of CIELAB values before and after different number of immersions into buffer solution of 29–30 May 2025, Ljubljana, Slovenia pH 2.2 (left) and pH 7 (right). pH 7 (right). ···  ··· CIE ···  L* ··· , ··· CIE  ··· CIE L* , ··· a*  , ··· ···  CIE ··· CIE a* , b* ···  ··· CIE b* Figure 2 shows that the colour change on the printed fabric is reversible. It varies with the number of immersions Figure 2 shows that the colour change on the printed fabric is reversible. It varies with the number of and then in pH 7 buffer solution show that the reversibility is maintained but varies with the number of immersions. in the buffer solution. The CIELAB colour values after immersing the samples first in the pH 2.2 buffer solution immersions in the buffer solution. The CIELAB colour values after immersing the samples first in the pH 2.2 4 buffer solution and then in pH 7 buffer solution show that the reversibility is maintained but varies with the number of immersions. In Figure 3 the K/S values versus wavelength of printed samples before and after immersion into buffer solutions In Figure 3 the K/S values versus wavelength of printed samples before and after immersion into buffer of different pH values are presented. In can be seen a significant decrease in the K/S value at 600 nm for the solutions of different pH values are presented. In can be seen a significant decrease in the samples immersed in buffer solutions with a pH of 2.2 and 3, and an increase in the K/S value at 600 nm for the K/S value at 600 nm for the samples immersed in buffer solutions with a pH of 2.2 and 3, and an increase in the samples immersed in buffer solutions from pH 4 to pH 11, compared to the sample before immersion (Figure 3). K/S value at 600 nm for the samples immersed in buffer solutions from pH 4 to pH 11, compared to the sample before At 450 nm, an additional increase in the K/S values of the printed samples immersed in buffer solutions from pH immersion (Figure 3). At 450 nm, an additional increase in the 2.2 to pH 4 is observed.K/S values of the printed samples immersed in buffer solutions from pH 2.2 to pH 4 is observed. K/S 7 0,7 S_pH 7 pH 7 S_pH 2.2 6 S_pH 5 0,6 pH 9 S_pH 3 S_pH 6 pH 11 S_pH 4 S_pH 9 5 0,5 pH 6 S_pH 5 S_pH 11 pH 5 S_pH 6 S_pH 4 4 S_pH 7 S 0,4 pH 4 S_pH 9 S_pH 3 A 3 S_pH 11 S_pH 2.2 0,3 S 2 0,2 pH 3 1 0,1 pH 2.2 0 0 400 450 500 550 600 650 700 400 450 500 550 600 650 700 λλ λλ (nm) (nm) Figure 3: K/S values of the printed samples as a Figure 4: Absorption spectra of BPB dye in Figure 3: K/S values of the printed samples as a Figure 4 : Absorption spectra of BPB dye in solutions with different pH values and after immersion. ― pH 2.2, ― pH 3, ―pH 4, ― pH 5, solutions with different pH values and after immersion. function of the wavelength before immersion in buffer buffer solutions of different pH values function of the wavelength before immersion in buffer buffer solutions of different pH values ― ― pH 2.2, ― pH 3, ―pH 4, ― pH 5, ― S, ― S_pH 2.2, ― S_pH 3, ― S_pH 4, ― S_pH 5, ― pH 6, ― pH 7, ― pH 9, ― pH 11 ― S_pH 6, ― S_pH 7, ― S_pH 9, ― S_pH 11 ― ― S, ― S_pH 2.2, ― S_pH 3, ― S_pH 4, ― S_pH 5, ― pH 6, ― pH 7, ― pH 9, ― pH 11 In contrast to the pH sensitivity of the BPB dye bound to the knitted fabric, the sensitivity of the BPB dye in ― S_pH 6, ― S_pH 7, ― S_pH 9, ― S_pH 11 reacts more strongly to pH changes in the buffer solution (Figure 4) than the dye bound to the knitted fabric In contrast to the pH sensitivity of the BPB dye bound to the knitted fabric, the sensitivity of the BPB dye in buffer (Figure 3). The BPB dye reacts more strongly to the pH value in the solution than on the knitted fabric. This is buffer solutions is different (Figure 4), as a comparison between Figure 3 and Figure 4 shows. The BPB dye due to the formation of dye-fibre interactions, which hinder the protonation and deprotonation of the dye, solutions is different (Figure 4), as a comparison between Figure 3 and Figure 4 shows. The BPB dye reacts more strongly to pH changes in the buffer solution (Figure 4) than the dye bound to the knitted fabric (Figure 3). The compared to the dye in the buffer solution, whose protonation and deprotonation are less hindered. When the BPB dye reacts more strongly to the pH value in the solution than on the knitted fabric. This is due to the formation pH was lowered from pH 4 to pH 2.2, there was a hypochromatic change in the absorption maximum of the of dye-fibre interactions, which hinder the protonation and deprotonation of the dye, compared to the dye in the BPB dye at 591 nm and the appearance of a new peak at 440 nm. The latter indicates that the dye is changing into a protonated form, resulting in a colour change from blue-violet to yellow-green. When the BPB dye is K/S value at 600 nm can be observed in Figure 3 when the pH drops from 4 to pH 2.2, and an increase in the 159 K/S bound to the knitted fabric and then immersed in buffer solutions with different pH values, a decrease in the value at 450 nm can be observed. The latter shows that the dye BPB bound to the knitted fabric is sensitive to pH but reacts worse to pH than when the dye is present in buffer solutions. The pH sensitivity of a BPB dye bound to knitted fabric depends not only on the strength of the dye-fibre interactions and thus the ability of the 29–30 May 2025, Ljubljana, Slovenia buffer solution, whose protonation and deprotonation are less hindered. When the pH was lowered from pH 4 to pH 2.2, there was a hypochromatic change in the absorption maximum of the BPB dye at 591 nm and the ap-pearance of a new peak at 440 nm. The latter indicates that the dye is changing into a protonated form, resulting in a colour change from blue-violet to yellow-green. When the BPB dye is bound to the knitted fabric and then immersed in buffer solutions with different pH values, a decrease in the K/S value at 600 nm can be observed in Figure 3 when the pH drops from 4 to pH 2.2, and an increase in the K/S value at 450 nm can be observed. The latter shows that the dye BPB bound to the knitted fabric is sensitive to pH but reacts worse to pH than when the dye is present in buffer solutions. The pH sensitivity of a BPB dye bound to knitted fabric depends not only on the strength of the dye-fibre interactions and thus the ability of the dye to protonate or deprotonate, but also on the wetting speed of the textile with the buffer solution (Van den Schueren, 2012). Since the wetting speed of textiles with the buffer solution depends mainly on the composition of the textile, the construction parameters of the textile (density and thickness of the textile, fineness of the yarns and number of yarn turns) (Van der Schueren, 2010) and the finishes that can reduce the hydrophilicity of the material (Stojkoski, 2020). In our case, the printed knitted fabrics were wetted in 15 to 20 seconds, while the colour change was observed after 15-20 minutes. 4. CONCLUSION In the study, a pH-sensitive textile sensor was created by applying the dye bromophenol blue to a polyamide/ elastane knitted fabric that reacts in the studied pH range from pH 2.2 to pH 11 and whose colour change is vis-ible to the naked eye. Direct flat screen printing is a suitable method for developing pH-sensitive textiles with the indicator dye bromophenol blue. The colour reaction of the indicator dye used in the buffer solution differs from that of the dye bound to the knitted fabric, whereby the dye-fibre interactions, which hinder the protonation or deprotonation of the indicator dye bromophenol blue, are of decisive importance. 5. REFERENCES Bamfield, P. 2001. Chromic Phenomena: Technological Applications of Colour Chemistry. Cambridge: Royal Society of Chemistry, pp. 1–8. Brunning, A. The chemistry of disposable nappies: absorbency, wetness indicators and waste. URL: https://www.compoundchem. com/2020/01/14/nappies/(last accessed on 31.1.2025). Christie, R.M. 2013. Chromic materials for technical textile applications. In Advances in the Dyeing and Finishing of Technical Textiles. pp. 3–36., Oxford, Cambridge, Philadelphia, New Delhi: Woodhead Publishing. Czarnecka, E., Walczak, M., Kumar, G., Piechota, G. and Nowaczyk, J. 2022. Degradation of biodegradable diapers as an element circular economy in waste containing various plastics. Journal of Cleaner Production. 377, 134426. Sachidhanandham, A., and Priyanka, M. 2020. A review on convenience and pollution caused by baby diapers. Science and Technology Development Journal. 23(3): 699–712. Sajovic, I., Kert, M., and Boh Podgornik, B. 2023. Smart textiles: A review and bibliometric mapping. Applied Sciences. 13(18): 10489. Stojkoski V. and Kert M. 2020. Design of pH responsive textile as a sensor material for acid rain. Polymers.12(10), 2251. Van der Schueren, L. and De Clerck, K. 2010. The use for pH-indicator dyes for pH-sensitive textile materials. Textile Research Journal. 80(7): 590–603. Van der Schueren, L. and De Clerck, K. 2012. Coloration and application of pH-sensitive dyes on textile materials. Coloration Tehnology. 128(2): 82–90. 160 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Mateja Kert Špela Jerebic and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Aškerčeva 12 Aškerčeva 12 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University Ljubljana University of Ljubljana spela.jerebic@gmail.com + 386 1 200 32 34 mateja.kert@ntf.uni-lj.si 161 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION DURABILITY OF THERMOCHROMIC INK PRINTED ON TEXTILE Diana Gregor-Svetec1 and Tina Flerin1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: This study examines the stability of screen-printed thermochromic ink on textiles under various environ-mental conditions. RED 37C Thermochromic WB Screen ink was printed on cotton fabric using a semi-automatic INO Print 2002 E-70 machine. The durability of prints was assessed through optical density and CIELab* colori-metric measurements before and after exposure to moist-heat (80°C, 65% RH, 48h), xenon lamp light (48h), and dry rubbing (500 strokes). Results showed minimal optical density changes after moist-heat treatment, while light exposure and dry rubbing significantly affected magenta, reducing its optical density by nearly 50%. Colorimetric analysis revealed a substantial colour difference after light exposure, making the shift highly visible. Dry rubbing also caused noticeable changes. The textile itself remained largely unaffected. Findings confirm the sensitivity of thermochromic ink to environmental factors, particularly light, emphasizing the need for improved formulations for enhanced durability. Keywords: Thermochromic ink, optical density, colour change, light fastness, moist-heat treatment, dry rubbing. 1. INTRODUCTION Chromisem refers to the alteration of colour, and substances capable of demonstrating this phenomenon are termed chromic materials (Bamfield, 2010). Thermochromism is the phenomenon observed in thermochromic materials, where the colour changes in response to temperature variations. Thermochromic materials offer in-novative possibilities for various applications, including textiles. These dynamic materials enable both functional and aesthetic enhancements, making them ideal for smart textiles used in fashion, healthcare, functional clothing, and safety industries (Vu et al., 2024). By integrating thermochromic inks through printing techniques, textiles can exhibit temperature-sensitive visual changes, providing interactive and practical solutions. The two major types of thermochromic-active materials are leuco dye-based composites and thermochromic liquid crystals (Seeboth and Lotzsch, 2008). Leuco dyes are a prominent class of organic thermochromic com-pounds. They undergo reversible colour changes due to temperature-induced isomerization, transitioning be-tween colourless and coloured forms (Vu et al., 2024). However, the leuco dye-based thermochromic system is highly sensitive to UV radiation, as colour transformation may also occur when exposed to UV, which can break the lactone ring (Nagare et al., 2024). Organic thermochromic materials, whether leuco dye-based or thermo-chromic liquid crystals, are known for their low stability against light, chemicals, and high temperatures (Strižić Jakovljević et al., 2020). Friškovec et al. (2013) reported poor light fastness and stability at high temperatures. Similarly, Cabral et al. (2020) highlighted poor light fastness, though they also noted good rub and wash stability of thermochromic pigments screen-printed on a 50% cotton and 50% polyester substrate. The performance and durability of thermochromic inks printed on textiles, particularly their long-term usability under various conditions, were further studied by Cabral et al. (2023). They found out that although washing and rubbing can cause varying degrees of lightening in the sample colours, the results emphasized the poor light stability of thermochromic ink screen printed on polyamide/elastane textile. In our study thermochromic ink was screen printed onto textile, made from pure cotton. The objective of our re-search was to determine the stability of the prints under light exposure, moist-heat treatment, and dry rubbing. 162 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL 29–30 May 2025, Ljubljana, Slovenia 2.1 Materials The thermochromic ink used for printing onto textiles was RED 37C Thermochromic WB Screen, produced by Special FX Creative (Good Life Innovations Ltd. Newhaven, UK). It is a reversible thermochromic water based ink Special FX Creative (Good Life Innovations Ltd. Newhaven, UK). It is a reversible thermochromic water based 2002 E-70 screen printing machine (GrafcoAST, Camalò di Povegliano, Italy), a semi-automatic screen printing ink that appears red at room temperature and becomes colourless at high temperatures. By using a heat machine was used. A textile printing substrate used was knitted cotton fabric of 150 g/m 2 basis weight. In Figure source of 47ºC or above the ink becomes transparent and reveals what is beneath printed surface. For printing 1 the printed sample is seen. The thermochromic ink used for printing onto textiles was RED 37C Thermochromic WB Screen, produced by 47ºC or above the ink becomes transparent and reveals what is beneath printed surface. For printing the INO Print that appears red at room temperature and becomes colourless at high temperatures. By using a heat source of the INO Print 2002 E-70 screen printing machine (GrafcoAST, Camalò di Povegliano, Italy), a semi-automatic screen printing machine was used. A textile printing substrate used was knitted cotton fabric of 150 g/m2 basis weight. In Figure 1 the printed sample is seen. Figure 1: Printed textile sample 2.2 Methods Figure 1: Printed textile sample Printed textile was aged using standard techniques for accelerated aging: moist-heat based on standard SIST 2.1 Methods ISO 5630-3 and aging with a Xenon lamp based on standard ISO 105-B02. Moist-heat treatment was specimen to artificial light under specified conditions: 35°C chamber temperature, 50°C black standard tempera-performed at temperature of 80°C and 65% relative humidity. The light fastness test was conducted by ture, 35% relative humidity. For determination of the light fastness a Xenotest Alpha (Atlas, USA) was used. The exposing a textile specimen to artificial light under specified conditions: 35°C chamber temperature, 50°C black apparatus simulates and accelerates the natural weathering process, providing reliable results concerning the Printed textile was aged using standard techniques for accelerated aging: moist-heat based on standard SIST at temperature of 80°C and 65% relative humidity. The light fastness test was conducted by exposing a textile ISO 5630-3 and aging with a Xenon lamp based on standard ISO 105-B02. Moist-heat treatment was performed The dry rub fastness test was performed using a rubbing device Param RT-01 (Labthink Instruments Co., Med-results concerning the long-term behaviour of materials. In both cases, the exposure times was 48 h. ford, MA, USA), according to the ASTM D5264-98 standard (mass of weights: 900 g; speed: 106 cpm). The The dry rub fastness test was performed using a rubbing device Param RT-01 (Labthink Instruments Co., printed textile was rubbed against the unprinted paper in 500 strokes. The colour change was determined using Medford, MA, USA), according to the ASTM D5264-98 standard (mass of weights: 900 g; speed: 106 cpm). long-term behaviour of materials. In both cases, the exposure times was 48 h. USA) was used. The apparatus simulates and accelerates the natural weathering process, providing reliable standard temperature, 35% relative humidity. For determination of the light fastness a Xenotest Alpha (Atlas, using spectrophotometric measurements. Spectrophotometric measurements were conducted on the printed textile before and after exposure to the pre-Spectrophotometric measurements were conducted on the printed textile before and after exposure to the viously mentioned treatments. The optical density (OD) of the prints, which is a measure of the light absorbance spectrophotometric measurements. The printed textile was rubbed against the unprinted paper in 500 strokes. The colour change was determined colorimetric properties of the print were determined using X-Rite Eye-One i1Pro (X-Rite, Grand Rapits, MI, USA) MI, USA). The colorimetric properties of the print were determined using X-Rite Eye-One i1Pro (X-Rite, Grand spectrophotometer (measurement geometry: 45/0, observation angle: 10°, light source: D65 and 3.6 mm measur-Rapits, MI, USA) spectrophotometer (measurement geometry: 45/0, observation angle: 10°, light source: D65 ing aperture). The colour difference (ΔE*ab) was calculated according to Eq. (1). The colorimetric value of print and 3.6 mm measuring aperture). The colour difference ( of a material, was measured using a Gretag Matcbeth D19C densitometer (X-Rite, Grand Rapids, MI, USA). The absorbance of a material, was measured using a Gretag Matcbeth D19C densitometer (X-Rite, Grand Rapids, previously mentioned treatments. The optical density (OD) of the prints, which is a measure of the light ΔE*ab) was calculated according to Eq. (1). The before treatment was taken as a reference. colorimetric value of print before treatment was taken as a reference. ∆𝐸𝐸𝐸𝐸 ∗ ∗ 2 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 = � ( ∆𝐿𝐿𝐿𝐿 ∗ ) 2 + ( ∆𝑎𝑎𝑎𝑎 ) + (∆𝑏𝑏𝑏𝑏∗)2 (1) In the Eq. 1 ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∆𝐿𝐿𝐿𝐿 = 𝐿𝐿𝐿𝐿 0 − 𝐿𝐿𝐿𝐿 𝑇𝑇𝑇𝑇 ; ∆𝑎𝑎𝑎𝑎 = 𝑎𝑎𝑎𝑎 0 − 𝑎𝑎𝑎𝑎 𝑇𝑇𝑇𝑇 ; ∆𝑏𝑏𝑏𝑏 = 𝑏𝑏𝑏𝑏 are the differences calculated for untreated (0) 0 − 𝑏𝑏𝑏𝑏 𝑇𝑇𝑇𝑇 and treated (T) print. 3. RESULTS WITH DISCUSSION By measuring the optical density and colorimetric properties of the print, the durability of thermochromic ink can be evaluated. 3.1 Optical density 163 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS WITH DISCUSSION By measuring the optical density and colorimetric properties of the print, the durability of thermochromic ink can be evaluated. 3.1 Optical density Results of measured change in the optical density of printed thermochromic ink after exposure to different envi-ronmental factors are shown in Figure 2. In the subtractive CMYK model the red colour is created by combining magenta (M) and yellow (Y) inks. Optical density measurements are reported as contributions of C, M, Y, and K, even if some of these values (like cyan (C) or black (K)) are zero for pure red. Measurements of the optical density of prints after exposure to various treatments revealed differing effects on the CMYK colours. The optical density values under the influence of moist-heat treatment remain almost unchanged, with magenta and yellow showing a negligible change of -0.07. Exposure to light and dry-rubbing have a greater impact. After both treatments, the largest change is observed in magenta, where the optical density value is nearly halved, while for yellow and black, it decreases by 25% and 30%, respectively. Visual assessment showed that the differences are barely visible to the naked eye. Figure 2: Optical density of printed thermochromic ink before and after different treatments 164 29–30 May 2025, Ljubljana, Slovenia 3.2 Colorimetric properties Among colorimetric properties, the CIELAB colour coordinates L*, a* and b* were determined. In Table 1 values measured before and after treatments are presented. Table 1: Colorimetric values L*, a* and b* of the textile and print determined before treatment and 48 hours after, given as mean value and standard deviation. Untreated Moist-heat Light Dry-rub textile print textile print textile print print L* 92.10 61.95 91.25 64.01 91.92 71.30 62.76 (0.22) (0.48) (0.34) (0.45) (0.49) (0.31) (0.22) a* 2.14 56.35 2.13 52.78 1.27 34.79 53.83 (0.01) (0.90) (0.54) (0.50) (0.03) (0.61) (0.66) b* -6.37 29.72 -4.03 27.09 -2.66 28.39 27.20 (0.12) (0.82) (0.08) (0.45) (0.14) (0.88) (0.51) Colorimetric values changed after moist-heta treatment, with lightness (L*) changing less than the other two components. The greatest change was observed in the a* component. In Figure 3 the colour differences, ΔE*ab between the printed thermochromic ink before and after exposure to different treatments is presented. The colour difference ΔE* is greater than 3, indicating that it is visible. Increased temperature also affects the textile itself, ab with the b* component showing the most significant change. For the textile, the colour difference is smaller, below 3, meaning it is still visible and can partially contribute to the observed colour difference of the print. Colorimetric values changed significantly after light exposure. By far, the greatest change was observed in the a* component, while lightness, L* also changed considerably, whereas the b* component changed the least (Table 1). The colour difference, ΔE* of 24.4 is unacceptably high and disruptive. Despite the large difference in colorimetric values ab after light exposure, the standard deviation remains low, indicating uniform colour changes in the print under light exposure. Light exposure has only a minor impact on the colorimetric properties of the textile itself, with slight changes noted only in the b* component. The influence of the textile on changes in the colorimetric properties of the print after light exposure is negligible. The textile is also resistant to dry rubbing, with no change in its colour. The colorimetric differences on the print are visible, after rubbing, slight changes were observed in the a* and b* components. The colour difference, ΔE* after dry-rub of the printed thermochromic ink on the textile is 4.20, ab making it clearly visible and noticeable. Figure 3: Colour difference of textile and printed thermochromic ink after different treatments 165 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS The results indicate that the durability of thermochromic ink printed onto the textile varies depending on the envi-ronmental factors to which it is exposed. Our research confirmed that thermochromic ink is sensitive to external factors, particularly light. Moist-heat treatment causes minor colour shifts and negligible changes in the optical density of magenta and yellow. However, exposure to light and dry rubbing significantly affect the ink, particularly magenta, whose optical density is nearly halved. The light exposure leads to the most noticeable changes, partic-ularly in the a* component, and lightness, leading to disruptive colour change. Dry rubbing also results in visible alterations. The textile itself remains largely unaffected by different treatments. Overall, the findings emphasize the need for careful consideration of environmental factors when using thermochromic inks on textiles, as expo-sure to heat, light, and friction can influence both optical and colorimetric properties. 5. ACKNOWLEDGEMENT: This study was conducted as part of the research core fundings [Program P2-0213]. 6. REFERENCES: Bamfield, P., 2010. Chromic phenomena: technological applications of colour chemistry. Cambridge: Royal Society of Chemistry, pp. 75–95. Cabral, I., Souto, A.P., and Worbin, L., 2020. Experimental work: Thermochromic Leuco dyes. In: I. Cabral, A.P. Souto, and L. Worbin, eds. Dynamic Light Filters: Smart Materials Applied to Textile Design. Cham: Springer International Publishing, pp.33–63. Cabral, I., Santiago, D., and Steffens, F., 2023. Chromic textiles: Colour fastness properties and irreversible colour change behaviour of textiles screen printed with thermochromic, photochromic and hydrochromic colourants. Coloration Technology, 139(2), pp.200-208. Friškovec, M., Kulčar, R., and Klanjšek Gunde, M., 2013. Light fastness and high-temperature stability of thermochromic printing inks. Coloration Technology, 129, pp. 214-222. Nagare, S.M., Hakami, A., Biswas, P.K., et al., 2024. A review of thermochromic materials for coating applications: production, protection, and degradation of organic thermochromic materials. Journal of Coatings Technology and Research. https://doi.org/10.1007/s11998-024-00982-9 Seeboth, A. and Lötzsch, D., 2008. Thermochromic phenomena in polymers. Shrewsbury: Smithers Rapra Technology. Strižić Jakovljević, M., Kulčar, R., Friškovec, M., Lozo, B., and Klanjšek Gunde, M., 2020. Light fastness of liquid crystal-based thermochromic printing inks. Dyes and Pigments, 180, p.108482. Vu N.T., Nguyen, M.T., Hoan, X.N., Duc Nguyen, D., Chung, W., Chang, S.W. and Duc La, D., 2024. Exploring the potential of organic thermochromic materials in textile applications. Journal of Materials Science, 59, pp.14924–14947. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Faculty of Natural Sciences and Engineering and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Chair of Information University of Ljubljana University of Ljubljana Faculty of Natural Sciences Diana Gregor Svetec Tina Flerin Chair of Information and Graphic Arts Technology and Graphic Arts Technology Snežniška 5, Snežniška 5, 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia +386 1200 3272 diana.gregor@ntf.uni-lj.si 166 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION THE AUXETIC PROPERTIES OF WOVEN FABRIC Klara Kostajnšek1, Sebastijan Šmid1, Nuša Klančar1 and Matejka Bizjak1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Auxetic woven fabrics exhibit a negative Poisson‘s ratio (NPR), which means that they expand laterally when stretched. This unique property improves energy absorption and flexibility and makes them valuable for various applications. In this study, the auxetic behaviour of woven fabrics is investigated by analysing how the jacquard pattern and the weft density influence the Poisson‘s ratio. Two different patterns were created to we-ave fabrics in a complex double and double weft weave, using elastic and non-elastic yarns in the weft at three different weft densities. The results show that both the pattern and the weave contribute to NPR at different weft densities. A higher weft density leads to a more stable auxetic behaviour over a larger strain range, while a lower weft density increases the auxetic effects but with lower strain persistence. These results emphasise the potential of auxetic woven fabrics for applications in sportswear, compression garments and flexible textiles. Keywords: Poisson’s ratio, auxetic woven fabric, PBT, jacquard patterns, weave, density 1. INTRODUCTION An auxetic woven fabric is a fabric with negative Poisson’s ratio (NPR), which means that when it is stretched in one direction, it expands laterally (in the perpendicular direction) instead of contracting like most conventional fabrics. Compared to conventional materials, the negative Poisson’s ratio gives auxetic textiles special properties, improved properties such as mechanical properties, ductility, fracture toughness, energy absorption capacity and the like, which offer more application possibilities (EEvans, K. 1991). Most early research on auxetic textiles focused on knitted fabrics as they are inherently stretchable and flexible, but woven fabrics have become an increasingly important field of research as they exhibit different mechanical properties and structural behaviour compared to knitted fabrics. There are two main approaches to the production of auxetic woven fabric. One uses auxetic fibres or yarns and the other uses conventional yarns, focusing on the geometric arrangement of the fab-ric structures to achieve auxetic behaviour (Zulifqar et al., 2017; Cao et al., 2019; Széles, 2023). The production of auxetic woven fabrics from conventional yarns with lower thickness and better formability that can be easily formed into garments is still a major challenge for weaving specialists (Zulifqar et al., 2017; Cao et al., 2019; Széles, 2023). To investigate the auxetic potential of woven fabrics for apparel purposes, we produced two jacquard patterns in three different weft densities. We used elastic PBT yarns and inelastic CO yarns in the weft and investigated how the different patterns and weft densities impact the Poisson’s ratio. The auxetic behaviour is evaluated based on the woven structure, pattern shape and weave of the fabric including the variable density factor. 2. EXPERIMENTAL 2.1 Materials and methods Six fabric samples were designed by using the Arahne CAD programme for weaving (Arahne d.o.o., Slovenia). They were woven on the same cotton warp (2 x 8 tex), with the same settings and conditions, on the Minifaber weaving machine with electronic Jacquard T.I.S. (Minifaber, Italy). To achieve an auxetic and aesthetic effect of the fabric, we chose two patterns (Fig. 1). We used diagonal geometric patterns to achieve a better auxetic effect. The warp density was 40 threads/cm, the weft density varied between 35, 40 and 45 threads/cm for Sample 1 and 167 29–30 May 2025, Ljubljana, Slovenia 25, 30 and 35 threads/cm for Sample 2. Sample 1 fabrics were woven in a complex double 6-end twill weave (Fig. 29–30 May 2025, Ljubljana, Slovenia 1 -left), Sample 2 were woven in weft-backed weave of 4-end twill and plain weave (Fig. 1 – right), both woven with a 1 : 1 sequence (1 white PBT multifilament 2 x 7.8 tex : CO, 2x8 tex). After weaving, the fabrics were heat treated with steam to gain the elastic potential of the PBT weft threads. The different densities for the Sample 1 weft density of more than 35 threads/cm, as the laboratory weaving machine is not equipped with a warp and Sample 2 were chosen because the woven structures are very different and the Sample 2 could not be woven let-off motion that would allow this. with a weft density of more than 35 threads/cm, as the laboratory weaving machine is not equipped with a warp let-off motion that would allow this. black effect white effect black effect white effect Figure1: Pattern and weave for Sample 1(left), pattern and weave for Sample 2 (right) The tensile tests, which we recorded with a camera, were performed along the elastic range (weft Figure1: Pattern and weave for Sample 1(left), pattern and weave for Sample 2 (right) direction) on an Instron 5567. The capacity of the load cell used was 500 N, the gauge length and tensile The tensile tests, which we recorded with a camera, were performed along the elastic range (weft direction) on an speed were set to 150 mm and 50 mm min-1 respectively. The results were analysed with images taken Instron 5567. The capacity of the load cell used was 500 N, the gauge length and tensile speed were set to 150 every 3 seconds. mm and 50 mm min-1 respectively. The results were analysed with images taken every 3 seconds. 3. RESULTS WITH DISCUSSION The results of the Poisson’s ratio values and the corresponding longitudinal strain of Sample 1 and 3. RESULTS WITH DISCUSSION Sample 2 with three different densities. The results of the Poisson’s ratio values and the corresponding longitudinal strain of Sample 1 and Sample 2 with Table 1 : Poisson’s ratio values and corresponding longitudinal strains of fabrics with three different three different densities. densities Table 1 Sample Maximum negative Corresponding Poisson’s ratio is negative : Poisson’s ratio values and corresponding longitudinal strains of fabrics with three different densities Poisson’s longitudinal up to ratio strain (%) longitudinal strain (%) Sample Maximum negative Po - Corresponding lon - Poisson’s ratio is negative Sample 1_45 -0,76 6,67 60,00 isson’s gitudinal up to Sample 1_40 -0,29 11,67 53,33 Sample 1_45 Sample 2_35 -0,76 3,33 15,00 -0,76 6,67 60,00 Sample 2_30 Sample 1_35 -1,51 ratio strain (%) 1,67 longitudinal strain (%) 41,67 Sample 1_40 -0,29 11,67 53,33 Sample 2_25 -1,43 1,67 23,33 -2,17 1,67 26,67 Sample 1_35 -1,51 1,67 41,67 different weft densities, but the extent of this effect is different. Sample 2_30-1,43 1,67 23,33 Sample 1 (at 45, 40, 35 threads/cm) generally maintains auxetic behaviour over a wider strain range The results (Table 1) show that both samples exhibit auxetic behaviour (negative Poisson’s ratio) at Sample 2_35-0,76 3,33 15,00 than Sample 2. For Sample 2, the maximum negative Poisson’s ratios are higher (indicating stronger Sample 2_25-2,17 1,67 26,67 The results (Table 1) show that both samples exhibit auxetic behaviour (negative Poisson’s ratio) at different weft Sample 1, the negative Poisson’s ratio decreases with decreasing weft density, but the fabric retains its auxetic behaviour), but this effect is rather short-lived, especially when the weft density decreases. For densities, but the extent of this effect is different. auxetic behaviour over a wider strain range. For Sample 2, the negative Poisson’s ratio becomes Sample 1 (at 45, 40, 35 threads/cm) generally maintains auxetic behaviour over a wider strain range than Sample stronger (more negative) with decreasing weft density, but the auxetic behaviour is only maintained for a shorter range of longitudinal strain. 2. For Sample 2, the maximum negative Poisson’s ratios are higher (indicating stronger auxetic behaviour), but this effect is rather short-lived, especially when the weft density decreases. For Sample 1, the negative Poisson’s Figures 2 and 3 illustrate the variation in Poisson’s ratio with increasing longitudinal strain for different ratio decreases with decreasing weft density, but the fabric retains its auxetic behaviour over a wider strain range. patterns, weave structures and weft densities. The results confirm that the weave pattern and weft For Sample 2, the negative Poisson’s ratio becomes stronger (more negative) with decreasing weft density, but density significantly influence the auxetic properties. Higher weft densities contribute to a more stable the auxetic behaviour is only maintained for a shorter range of longitudinal strain. auxetic effect over a wider strain range, while lower weft densities enhance auxetic behaviour but only at lower strains. 168 2 29–30 May 2025, Ljubljana, Slovenia Figures 2 and 3 illustrate the variation in Poisson’s ratio with increasing longitudinal strain for different patterns, weave structures and weft densities. The results confirm that the weave pattern and weft density significantly in 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia -fluence the auxetic properties. Higher weft densities contribute to a more stable auxetic effect over a wider strain range, while lower weft densities enhance auxetic behaviour but only at lower strains. Sample 1 with complex double 6-end twill weave shows a strong initial auxetic effect, especially at the lower weft Sample 1 with complex double 6-end twill weave shows a strong initial auxetic effect, especially at the Sample 1 with complex double 6-end twill weave shows a strong initial auxetic effect, especially at the densities (35 threads/cm). However, the auxetic effect decreases after about 50% longitudinal strain. lower weft densities (35 threads/cm). However, the auxetic effect decreases after about 50% longitudinal lower weft densities (35 threads/cm). However, the auxetic effect decreases after about 50% longitudinal strain. strain. Sample 1 Sample 1 45 45 40 40 35 35 0,20 0,20 0,00 0,00 -0,20 0 0 10 10 20 20 30 30 40 40 50 50 60 60 70 70 80 80-0,20 io io -0,40-0,40 at at-0,60-0,60 s R s R-0,80-0,80 on' on' ss ss-1,00-1,00 Poi Poi-1,20-1,20 -1,40-1,40 -1,60-1,60 Longitudinal strain [%] Longitudinal strain [%] Figure 2 Figure 2 : Poisson`s ratio vs. longitudinal strain curve of Sample 1 at three different weft densities : Poisson`s ratio vs. longitudinal strain curve of Sample 1 at three different weft densities Figure 2: Poisson`s ratio vs. longitudinal strain curve of Sample 1 at three different weft densities Sample 2 with double structure (4-end twill and plain) (Figure 3) exhibits a more stable auxetic response com Sample 2 with double structure (4-end twill and plain) (Figure 3) exhibits a more stable auxetic response Sample 2 with double structure (4-end twill and plain) (Figure 3) exhibits a more stable auxetic response -pared to Sample 1, whereby the values fluctuate slightly but remain predominantly negative, but the auxetic compared to Sample 1, whereby the values fluctuate slightly but remain predominantly negative, but the compared to Sample 1, whereby the values fluctuate slightly but remain predominantly negative, but the response disappears after about 15% – 20% longitudinal strain. The highest auxetic response is observed in the auxetic response disappears after about 15% – 20% longitudinal strain. The highest auxetic response auxetic response disappears after about 15% – 20% longitudinal strain. The highest auxetic response fabric with a lower weft density (25 threads/cm). is observed in the fabric with a lower weft density (25 threads/cm). is observed in the fabric with a lower weft density (25 threads/cm). Sample 2 25 25 30 30 35 35 Sample 2 0,50 0,50 io 0 0 5 5 10 10 15 15 20 20 25 25 30 30 35 35 io-0,50-0,50 at 0,00 0,00 at s R -1,00-1,00 s R on' on' -1,50-1,50 ss ss Poi Poi -2,00-2,00 -2,50-2,50 Longitudinal strain [%] Longitudinal strain [%] Figure 3 Figure 3 : Poisson`s ratio vs. longitudinal strain curve of sample 2 at three different weft densities : Poisson`s ratio vs. longitudinal strain curve of sample 2 at three different weft densities Figure 3 : Poisson`s ratio vs. longitudinal strain curve of sample 2 at three different weft densities 3.1 Influence of weft density on the auxetic properties Higher weft densities (Sample 1_ 45, 40 threads/cm) show a more stable auxetic behaviour with a wider 3.1. Influence of weft density on the auxetic properties 3.1. Influence of weft density on the auxetic properties Higher weft densities (Sample 1_ 45, 40 threads/cm) show a more stable auxetic behaviour with a wider Higher weft densities (Sample 1_ 45, 40 threads/cm) show a more stable auxetic behaviour with a wider range range of deformations. Sample 1 shows the best auxetic response at a 45 threads/cm weft density. It range of deformations. Sample 1 shows the best auxetic response at a 45 threads/cm weft density. It of deformations. Sample 1 shows the best auxetic response at a 45 threads/cm weft density. It does not have the does not have the maximum value of the negative Poisson's ratio, but with a value of -0.4 at 10 % strain does not have the maximum value of the negative Poisson's ratio, but with a value of -0.4 at 10 % strain maximum value of the negative Poisson’s ratio, but with a value of -0.4 at 10 % strain and with values around and with values around -0.2 at 25 % strain, it offers adequate auxetic properties of the fabrics. In contrast and with values around -0.2 at 25 % strain, it offers adequate auxetic properties of the fabrics. In contrast -0.2 at 25 % strain, it offers adequate auxetic properties of the fabrics. In contrast to the Sample 1 with the lowest to the Sample 1 with the lowest density of 35 threads/cm, which shows the highest negative Poisson's to the Sample 1 with the lowest density of 35 threads/cm, which shows the highest negative Poisson's ratio at 2.5% elongation, which already decreases rapidly at 5% elongation. ratio at 2.5% elongation, which already decreases rapidly at 5% elongation. When comparing Figure 2 and Figure 3, we can see clear differences in the auxetic behaviour of the When comparing Figure 2 and Figure 3, we can see clear differences in the auxetic behaviour of the fabrics, which can be attributed to the different structure and weft density. The Sample 2 fabrics with a fabrics, which can be attributed to the different structure and weft density. The Sample 2 fabrics with a 169 29–30 May 2025, Ljubljana, Slovenia density of 35 threads/cm, which shows the highest negative Poisson’s ratio at 2.5% elongation, which already decreases rapidly at 5% elongation. When comparing Figure 2 and Figure 3, we can see clear differences in the auxetic behaviour of the fabrics, which can be attributed to the different structure and weft density. The Sample 2 fabrics with a lower weft density (25, 30 threads/cm) shows a stronger auxetic effect with a limited range of strain (negative Poisson’s ratio value of -0.5 to -1 at 5% strain and with values around -0.2 at 10-20% strain). Weft density affects the auxetic potential of fabrics, but this is also strongly related to the woven structure of the fabric. The weave, which determines the number of interlacing points or the flotation of the threads, together with the thread density, determines the frictional surfaces between the threads, which prevent them from moving freely and taking up a new position during stretching of the fabric. Sample 1, woven in a non-stitched double weave, which allows greater shrinkage of the fabric immediately after heat treatment and consequently a higher auxetic potential than Sample 2, with a more compact weft structure. 4. CONCLUSIONS For high performance applications (sportswear, activewear, sports compression or adaptive clothing), Sample 1 with a density of 45 threads/cm is the most suitable option with a maximum NPR of -0.76 and an extensive strain range of up to 60%. It offers both high auxetic behavior and good stretchability, which are crucial for comfort and fit in these applications. For moderate performance and low stretch, such as maternity wear, leggings and under-wear, Sample 1 with a density of 40 threads/cm with a moderate NPR of -0.29 and a strain range of up to 53.33% would be suitable. Sample 2 with densities of 35, 30 and 25 threads/cm with strong auxetic effects but limited stretchability (due to low longitudinal strain) are more suitable for compression garments, medical textiles or oth-er applications where controlled deformation is desired but high stretchability is not required. Regardless of the pattern, the general trend shows that higher weft density fabrics have more stable auxetic properties over larger strain ranges, while lower density fabrics have more pronounced but shorter-lived auxetic effects. 5. REFERENCES Ken E Evans, Auxetic polymers: a new range of materials, Endeavour, Volume 15, Issue 4, 1991, Pages 170-174, ISSN 0160-9327, https:// doi.org/10.1016/0160-9327(91)90123-S. Zulifqar A, Hua T, Hu H. Development of uni-stretch woven fabrics with zero and negative Poisson’s ratio. Textile Research Journal. 2018;88(18):2076-2092. doi:10.1177/0040517517715095 Cao H, Zulifqar A, Hua T, Hu H. Bi-stretch auxetic woven fabrics based on foldable geometry. Textile Research Journal. 2019;89(13):2694-2712. doi:10.1177/0040517518798646 Széles, Levente and Horvath, Richard and Cveticanin, Livija, Design and Parameter Dependency Assessment of a Novel Doubly Re-Entrant Auxetic Honeycomb. Available at SSRN: https://ssrn.com/abstract=4595331 or http://dx.doi.org/10.2139/ssrn.4595331 170 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Klara Kostajnšek Matejka Bizjak and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Aškerčeva 12, Aškerčeva 12, Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia +386 1 20 03 219 matejka.bizjak@ntf.uni-lj.si +386 1 20 03 214 klara.kostajnsek@ntf.uni-lj.si Sebastijan Šmid University of Ljubljana Faculty of Natural Sciences and Engineering Department of Textiles, Graphic Arts and Design Aškerčeva 12, 1000, Ljubljana, Slovenia sebastjan327@gmail.com Nuša Klančar University of Ljubljana Faculty of Natural Sciences and Engineering Department of Textiles, Graphic Arts and Design Aškerčeva 12, 1000, Ljubljana, Slovenia klancar.nusa@gmail.com 171 INNOVATIVE CHEMICAL TEXTILE PROCESSING 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION HYDROPHILICITY AND CAPILARITY OF COTTON FABRIC CATIONIZED DURING MERCERIZATION PROCESS Anita Tarbuk1, Ivona Nemčić1 and Tihana Dekanić1 1University of Zagreb Faculty of Textile Technology, Croatia Abstract: Cationization of cotton is an alternative method to improve the adsorption of anionic dyes and auxi-liaries as it changes the surface charge of the fibres. In this study, the hydrophilicity and capillarity of cationized cotton fabrics during mercerization were investigated after different ageing times of the cationic compound (1, 5 and 24 hours) in order to shorten the process time. It was found that cationization changes the zeta potential, hy-drophilicity and capillarity of the cotton fabric. The standard cotton fabric gets wet quickly and absorbs liquid, but remains wet for a long time, while it dries quickly after cationization. Therefore, the standard fabric is characterized as a “moisture management fabric” and the cationized fabric as “fast absorbing and fast drying fabric”. In terms of optimising the cationization process, it has been shown that ageing for 5 hours is sufficient to achieve similar properties to ageing for 24 hours, which significantly shortens the cationization process. Keywords: hydrophilicity, capillarity, cationization during mercerization, CHPTAC, zeta potential, MMT 1. INTRODUCTION The cationization of cotton is an alternative method for improving the adsorption of anionic dyes and auxiliaries, which leads to a change in the surface charge of the fibres (Figure 1). Epihalohydrins are the most commonly used cationic agents, namely epoxypropyltrimethylammonium chloride (EPTAC) and 3-chloro-2-hydroxy-propyl-trimethylammonium chloride (CHPTAC), while amines and quaternary ammonium compounds can be also used. This modification can be carried out by exhaustion and padding as a pre- or after-treatment technique (Lewis 1997, Hauser 2001, Hashem 2003, 2006, Aktek 2017) or during the mercerization process (Grancarić 2004, Tar-buk 2014, 2024). Figure 1: Cationization of cotton cellulose with CHPTAC 173 29–30 May 2025, Ljubljana, Slovenia The main difference between the two techniques is the result of the subsequent dyeing process. If cationization is performed in the pre- or after-treatment, the surface groups are blocked and the subsequent dyeing process are not uniform. If cationization is carried out during the mercerization process, a change in the cellulose crystal lattice occurs due to mercerization (Soljačić 1968), and a novel cellulose is formed in which the cationic compound is evenly distributed between the cellulose chains (Tarbuk 2014), so that the dyeing is uniform (Tarbuk 2014, 2016, Sutlović 2021, Čorak 2022). This technique was introduced in 2003 by the research group of Grancarić, Tarbuk and Dekanić in the slack mercerization of yarn (Grancarić 2004) and further developed in 2009 in the mercerization without tension on the jigger, resulting in a new cotton cellulose published in 2014 (Tarbuk), which has all the advantages of the two processes mentioned above. Apart from the articles by these authors, no published articles on cationization during the mercerization process were found. This modification completely changes the dye-cellulose system, resulting in uniform dyeing after the dyeing process with natural, direct, acid and metal complex, vat and reactive dyes and in inkjet printing, with no salt required (Tarbuk 2024). However, the cationization process involves a 24-hour ageing time. Therefore, this study investigated the hydrophilicity and capillarity of cationized cotton fabrics during mercerization after different ageing times of the cationic compound (1, 5 and 24 hours) with the aim of shortening the process time. 2. MATERIAL AND METHODS The standard cotton fabric for ISO 2267:1986 type 10A by wfk‐Testgewebe was used in this research. It is chem-ically bleached fabric of 100% cotton, plain weave, mass per unit area 170 g/m2, the warp and weft density 27/27 threads per cm, and the fineness of the yarn 29.5/29.5 tex, label ST. Cationization during mercerization was carried out according to Tarbuk (2014) using 3 ‐chloro‐2‐hydroxypropyl trimethylammonium chloride (CHPTAC, Sigma Aldrich) with the change in aging time. A two ‐step procedure on a jigger machine with 0% tenacity was performed at room temperature: 1. mercerization in a bath with 24% NaOH, 8 g/L Subitol MLF, and 2. alkaline cotton fabric before fixation (hot rinsing) was cationization in a bath with 50 g/L CHPTAC, sealed and left at room temperature to age 1, 5 or 24 h, followed by hot rinsing and neutralization in 5% acetic acid then cold rinsed to achieve a neutral pH and air dried. The samples were labelled as C1, C5 and C24 depending on the ageing time. To confirm the change in surface charge, the electrokinetic potential (zeta potential, ZP) was measured using the current flow method with a Brookhaven-Paar Electrokinetic analyzer (EKA) with a stamp cell in 0.001 M KCl as electrolyte. The measurements were carried out in the range of pH values 3 to 10, and zeta potential was calcu-lated according to the Helmholtz–Smoluchowsky equation (Grancarić 2005). Hydrophilicity and capillarity of the modified cotton were tested using the following standard test methods: AATCC TM 79-2010e2(2018)e3, Test Method for Absorbency of Textiles (»Drop test«), AATCC TM 197-2022, Vertical Wicking Rate of Textiles: to Specified Distances (»Vertical test«) and AATCC TM 195-2011e2(2017)e5, Liquid Moisture Management Properties of Textile Fabric on Moisture Manage-ment Tester (MMT; SDL Atlas, USA). 3. RESULTS AND DISCUSSION In this work, the possibility of shortening the process time of cationization of cotton during mercerization was in-vestigated. For this purpose, the cotton was cationized during mercerization with different ageing times (1, 5 and 24 hours) of the short-chain quaternary ammonium salt, an epihalohydrin, 3‐chloro‐2‐hydroxypropyl trimethylam-monium chloride (CHPTAC) and its zeta potential, hydrophilicity and capillarity were investigated. 174 29–30 May 2025, Ljubljana, Slovenia The results of zeta potential of standard and cationized cotton fabrics vs. pH value of 0.001 M KCl are shown in Figure 2. ] 10 [mV ST C1 C5 C24 ζ 5 pH 0 2 3 4 5 6 7 8 9 10 11 -5 -10 -15 -20 -25 Figure 2: Zeta potential of standard and cationized cotton fabrics vs. pH value of 0.001 M KCl The results of the zeta potential (Figure 2) show that the standard cotton fabric (ST) has a negative charge, which is due to the dissociation of the hydroxyl groups of the cotton cellulose. The electrical charge of the cotton has changed significantly due to cationization with CHPTAC, which was introduced into the open cellulose structure during mercerization and binds covalently to the available groups. The binding of CHPTAC creates the new amino groups, which also dissociate, giving the cotton fibre a more positive charge. The efficiency of the cationization process at different ageing times, monitored by measuring the zeta potential, shows that 24-hour ageing is not necessary. At 24-hour (C24) and 5-hour (C5) ageing, the zeta potential is similar. The results of hydrophilicity, capillarity and moisture management properties of cotton cationized during mercer-ization, are presented in Tables 1 and 2, and Figure 3. Table 1: The absorbency (»Drop test« according to AATCC TM 79-2018) and the vertical wicking rate (W) in time for a short distance, d=20 mm (»Vertical test« according to AATCC TM 197-2022) of standard and cation-ized cotton fabrics t (s) t (s) W (mm/s) Fabric (Drop test) (Short distance: d=20 mm) ST 0 117.33 0.171 C1 0 44.61 0.448 C5 0 62.16 0.322 C24 0 52.46 0.381 The results of the “drop test” (Table 1) of 0 s for the absorption of all fabrics show that the hydrophilicity was re-tained after modification. However, the wetting time (WT) in Table 2, which was measured with the MMT device, reveals the difference in the wetting behaviour between the fabrics. Table 1 shows the vertical wicking rate for a short distance (d=20 mm), as the 150 mm mark was not reached in 30 min. It can be seen that all cationized 175 29–30 May 2025, Ljubljana, Slovenia fabrics absorb liquid faster than unmodified standard fabric (ST). The time and the distance waterfront reached in 30 min are shown in Figure 3. From the slope of the curves in Figure 3 and the time of the vertical wicking test for a short distance, it can be seen that for a distance of 20 mm, standard cotton fabrics (ST) required 117 s and cationized cotton fabrics less than 62 s, and the wicking rate is calculated accordingly. Figure 3: Distance (d) waterfront as a function of time (t) in a 30-minute vertical wicking test on standard and cationized cotton fabrics The absorption rate (AR) in Table 2 represents the average absorption of liquid moisture for the top and bottom of the sample. The results in Table 2 that it is about 20 %/s for ST and it changes to 60-70 %/s during the cationiza-tions. These results, again, indicate better capillarity of C1, C5 and C24 than ST. For this reason, the spreading speed (SS), which represents the speed of surface wetting from the centre of the sample to the maximum wetting radius, is faster on cationic surfaces than on standard surface (2.8 mm/s for ST to 3.7 mm/s for C1, C5, C24). The results of the vertical test confirm these results (Table 1). Within 30 minutes, the water penetrates 55 mm in ST fabric and up to 71 mm for C24 fabric due to capillarity (Figure 3). Table 2: Moisture Management Test results on the ST and cationized cotton fabrics Fabric WT-T WT-B AR-T AR-B MWR-T MWR-B R SS-T SS-B OMMC (mm/s) (mm/s) (s) (s) (%/s) (%/s) (mm) (mm) (%) ST 4.96 3.61 19.78 22.51 23.33 23.33 2.89 2.74 419.26 0.67 C1 3.15 3.34 70.22 58.08 20 20 3.76 3.62 81.09 0.49 C5 3.20 3.37 71.46 58.19 20 20 3.70 3.58 89.34 0.50 C24 3.13 3.37 69.65 63.97 20 20 3.72 3.56 13.62 0.43 *WT – wetting time; AR – absorption rate; MWR – maximum wetted radius; SS – spreading speed; R – accumu-lative one-way transport capability; OMMC – overall (liquid) moisture management capability; at any quantity: T – top surface; B – bottom surface. 176 29–30 May 2025, Ljubljana, Slovenia Accumulative one-way transport capability (R) in Table 2 represents the difference between the area of the liquid moisture content curves of the top and bottom surfaces of a specimen with respect to time. For ST it is 419.26%, which means that water content on top surface is much higher than on bottom indicating a high absorbency. Cat-ionization significantly lowers accumulative one-way transport capability, which indicates that the water content on the top surface is no longer much higher than on the fabric bottom surface. This suggests that the liquid introduced to the bottom surface is slowly transferred to the top surface (Nemcokova et al 2015). Overall (liquid) moisture management capability (OMMC) is calculated by combining three measured performance characteristics: the ab-sorption rate on the bottom surface, the one-way liquid transport capability, and the maximum spreading speed on the bottom surface. It represents an index of the overall capability of a fabric to transport liquid moisture (AATCC TM 195). It is very good for the TS fabric, whereas OMMC in only good for cationized fabrics. The ST fabric gets wet quickly and absorbs liquid, which quickly reaches the bottom side of the fabric, but the fabric remains wet for a long time. Therefore, the ST fabric is characterized as “moisture management fabric”. After cationization, the properties change and the liquid is absorbed extremely quickly, but also dries very quickly. Since all cationized fabrics have fast wetting, absorption and spreading, large spreading area, but poor one-way transport the cationized fabrics are characterized as “fast absorbing and fast drying fabrics”. 4. CONCLUSION Cationization during mercerization changes the hydrophilicity and capillarity of the cotton fabric. A high number of –OH and –COOH groups gives cotton fabrics a negative zeta potential. Cationization has changed the sur-face charge; -NH groups leads to a more positive charge. The ST fabric gets wet quickly and absorbs liquid, but 2 remains wet for a long time. After cationization, it dries very quickly. Therefore, the ST fabric is characterized as “moisture management fabric”, while cationized fabrics are “fast absorbing and fast drying fabrics”. With regard to the optimization of the cationization process, it could be shown that an aging of 5 hours is sufficient for CHPTAC and that an aging of 24 hours (as in the literature) is not necessary, which considerably shortens the cationization process. 5. ACKNOWLEDGEMENT This work has been supported in part by the Croatian Science Foundation project “HPROTEX: Hospital Protective Fabrics” (UIP‐2017‐05‐8780, 2019-2023). 6. REFERENCES Aktek, T., Millat, A. K. M. M. (2017) “Salt free dyeing of cotton fiber—A critical review”. Int J Text Sci 6 (2), pp. 21-33. Čorak, I., Brlek, I., Sutlović, A., Tarbuk, A. (2022) “Natural Dyeing of Modified Cotton Fabric with Cochineal Dye”. Molecules 27 (3), 1100, pp. 1-13. Grancarić, A. M., Tarbuk, A., Dekanić, T. (2004) “Elektropozitivan pamuk”. Tekstil 53 (2), pp. 47-51. Grancaric, A. M., Tarbuk, A., Pušić, T. (2005) “Electrokinetic properties of textile fabrics”. Coloration Technology 121 (4), pp. 221–227. Hashem, M., Hauser, P., Smith B. (2003) “Reaction Efficiency for Cellulose Cationization Using 3-Chloro-2-Hydroxypropyl Trimethyl Ammonium Chloride”. Textile Research Journal 73 (11), pp. 1017-1023. Hashem, M. M. (2006) “Development of a one-stage process for pretreatment and cationisation of cotton fabric”. Coloration Technology 122 (3), pp. 135–144. Hauser, P. J., Tabba, A. H. (2001). “Improving the environmental and economic aspects of cotton dyeing using a cationised cotton”. Coloration Technology 117 (5), pp. 282–288. Lewis, D. M., Mcllroy, K. A. (1997) “The chemical modification of cellulosic fibres to enhance dyeability”. Review of Progress in Coloration and Related Topics 27 (1), pp. 5–17. Nemcokova, R., Glombikova, V., Komarkova, P. (2015) “Study on Liquid Moisture Transport of Knitted Fabrics by Means of MMT”. AUTEX Research Journal 15 (4), pp. 233-242. Soljačić, I., Žerdik, M. (1968). “Mercerizacija pamuka”. Tekstil, 17, 495-518. Sutlović, A., Glogar, M. I., Čorak, I., Tarbuk, A. (2021) “Trichromatic Vat Dyeing of Cationized Cotton”. Materials 14 (19), 5731, pp. 1-17. 177 29–30 May 2025, Ljubljana, Slovenia Tarbuk, A. (2024) “The sustainability of the cotton cationization during the mercerization process”. Journal of Chemists, Technologists and Environmentalists 5 (1), pp. 1–13. Tarbuk, A., Grancarić, A. M., Leskovac, M. (2014) “Novel cotton cellulose by cationisation during the mercerisation process—part 1: chemical and morphological changes”. Cellulose 21 (3), pp. 2167–2179. Tarbuk, A., Grancarić, A. M., Leskovac, M. (2014) “Novel cotton cellulose by cationization during mercerization—part 2: the interface phenomena”. Cellulose 21 (3), pp. 2089–2099. Tarbuk, A., Sutlović, A., Dekanić, T., Grancarić, A. M., Zdjelarević, I. (2016) “Ultra-Deep Black Cationized Cotton by Metal-Complex Dyeing”. In 16th World Textile Conference AUTEX 2016 – Proceedings, edited by Barbara Simončič, Brigita Tomšič, Marija Gorjanc, pp. 5.3.(1-7), Ljubljana, University of Ljubljana, Faculty of Sciences and Engineering, Department of Textiles, Graphic Arts and Design. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Anita Tarbuk Tihana Dekanić Faculty of Textile Technology Faculty of Textile Technology Department of Textile Department of Textile University of Zagreb University of Zagreb Chemistry and Ecology Chemistry and Ecology Prilaz baruna Filipovića 28a Prilaz baruna Filipovića 28a HR-10000 Zagreb, Croatia +38514877356 HR-10000 Zagreb, Croatia tihana.dekanic@ttf.unizg.hr +38514877356 anita.tarbuk@ttf.unizg.hr 178 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION THE ROLE OF TRISODIUM PHOSPHATE IN ENHANCING ACIDIC DYEING OF NYLON FABRICS Gaye Duman1, Özgür Baki̇1, Mert Bakirli1 and Güngör Durur2 1Asli Textile Clothing Industry Inc., Turkey 2Pamukkale University, Turkey Abstract: Nylon fabrics are dyed in acidic environments through ionic bonding, where positively charged amino groups on the fabric interact with the negatively charged sulfonate groups of acidic dyes. The optimal pH range for the nylon dyeing process is between 4 and 6, and acetic acid (AA) is commonly employed to regulate and achieve this pH level. However, even at low concentrations, AA alone can cause a rapid decrease in the dye bath pH. Such abrupt pH reductions can lead to color inconsistencies and dye breaks, particularly in large-scale textile production where fabrics are dyed in bulk. This study proposes the use of trisodium phosphate (TSP) as a buffering agent in conjunction with AA to mitigate these challenges. The incorporation of TSP facilitates a more controlled and gradual decline in pH, thereby preventing the fabric from rapidly adsorbing the dye in an uncon-trolled manner. By enabling the fabric to adsorb the majority of the dye before reaching the optimal pH levels, the remaining dye can be evenly fixed onto the fabric, minimizing the risk of color irregularities and ensuring a more uniform dyeing outcome. Keywords: Trisodium Phosphate, TSP, Nylon, Acidic Dyeing, Buffering Effect, pH Control 1. INTRODUCTION Nylon is a polyamide polymer which has positively charged amino (-NH₃⁺) groups and negatively charged car-boxyl (-COO⁻) groups similar to other protein fibers such as wool and silk (Kertess, 1949). These categories of fibers are generally dyed in an acidic environment with various acid dyes (Kim, 2011). A decrease in pH in the dye bath leads to a greater positive charge on the fiber, as the ionization of the carboxyl group diminishes, and the amino groups undergo increased protonation. The fabric, enriched with positively charged amino (-NH₃⁺) groups, becomes highly receptive to bonding with the dye’s negatively charged sulfonates (-SO3₂). Amino groups of the fiber form ionic bonds with anionic dye molecules (Dawson, 1981). As the number of amino groups increases, the fabric’s capacity to adsorb dye molecules is enhanced. Acetic acid is a commonly used chemical in the acidic dyeing of nylon fibers. It is used to decrease the pH value of the dye bath and to achieve acidity. An acidic medium is necessary to get strong ionic bonds between dye mol-ecules and the fibers, so maintaining the range of pH 4–6 is crucial (Dawson, 1981). This necessitates the use of acetic acid as a pH-regulating chemical. Acidic conditions are essential for dyeing nylon with acid dyes; however, due to the strong affinity of these dyes for nylon fabrics, it is crucial to maintain strict control over the dye bath. Two primary factors influence the dye adsor-ption capacity of nylon fabric: temperature and pH. As the temperature rises, the fabric‘s ability to adsorb dye in-creases. Similarly, a decrease in pH enhances dye adsorption. If the pH decreases too rapidly, the dye penetrates the fabric quickly, leading to a situation where the reaction rate surpasses the diffusion rate. This discrepancy can result in color unevenness and dye breaks. Therefore, for optimal and controlled dyeing, it is essential to regulate both temperature and pH throughout the dyeing process. The use of buffers in the dyeing process has a critical importance in achieving high-quality products. Buffers stabilize the pH and prevent sudden chain reactions in the dyeing medium. The pH stabilization allows the dye to diffuse and penetrate the fabric slowly, preventing color inconsistencies and irregularities (Soleimani-Gorgani, 2006). 179 29–30 May 2025, Ljubljana, Slovenia Trisodium phosphate (TSP), Na₃PO₄, is a compound commonly used as a buffer in reactive and disperse dye applications (Subramanian, 1932, Lee, 2006). It creates a strong alkaline solution when dissolved in water and dissociates into sodium ions (Na+) and phosphate ions (PO₄³⁻). The phosphate ion acts as a weak base and can react with water to bind hydrogen ions (H⁺) or neutralize excess hydroxide ions (OH⁻) in the solution. The buff-ering capacity of TSP is achieved through the conversion of phosphate ions (PO₄³⁻) into dihydrogen phosphate (H₂PO₄⁻), and hydrogen phosphate (HPO₄²⁻) forms in the solution. These transformations help maintain the bal-ance of the solution’s pH. When acid (H⁺ ions) is added to the solution, phosphate ions bind to these H⁺ ions and convert into dihydrogen phosphate ions. These reactions help prevent a further decrease in pH (Dawson, 1981, Maulik, 2022). Lin et al. (FB, 2007) investigated the relationship between the pH values of the dye bath and the dye exhaustion rate of the fiber. They also examined the effects of various acids and pH-sliding agents used to gradually reduce the pH of the bath through heating, to control the dyeing process of nylon fibers with metal complex acid dyes. They showed nearly 10% and 15% decreases in dye exhaustion when the final pH value was set between 5~6 and 6~7, respectively, compared to the pH value at 4.5. Between different combinations of agents, the acetic acid-based pH-sliding agent demonstrated superior performance in achieving uniform dyeing of nylon fabrics compared to the others. In another study, reactive dyeing of nylon fiber was investigated with the use of TSP as a buffer to arrange pH values for optimum dye exhaustion, and fixation by Lee et al (Lee, 2006). They revealed that all reactive dyes are applicable at pH 5-6, but for enhanced fixation efficiency, the sulphato-ethylsulphone groups should be converted to vinylsulphone before dyeing with trisodium phosphate. While TSP can serve as a buffering agent in different applications, it is not commonly used for dyeing nylon fibers under acidic dyeing conditions. This study aims to ensure the homogeneous distribution of dye on nylon fabric surfaces by using trisodium phosphate (TSP) alongside acetic acid during dyeing with acidic dyes. The method focuses on gradually lowering the pH of the dye bath, thereby preventing sudden pH changes that could lead to dye breaks. 2. MATERIALS AND METHOD 2.1 Materials All chemicals used in the experiments were purchased commercially from Sigma Aldrich, with the same quality as those used in large-scale dyeing at the facility. Knitted nylon 6 fabrics, each weighing 10 grams and composition of 95% nylon and 5% elastane, were used from the fabrics that customers of Ideateks Textile sent to our factory to be dyed. The two acidic dyes used in this work were supplied by Setaş Chemical Industry Inc.; one of the dyes was 1:2 pre-metalized acid dye C.I Acid Blue 193, which has two sulfonate groups, and the other C.I Acid Blue 62, which is monosulfonated. As a pH-regulating chemical, acetic acid (AA, 99%) and as a buffer trisodium-phosphate (TSP, 96%) were used. Ultra-pure water was used in all experiments. 2.2 Method 2.2.1 Dyeing Procedure Nylon 6 fabric was dyed in sealed, stainless steel dyeing vessels of 150 cm3 capacity, housed in a Rapid Eco Dyer ECO-24 laboratory-scale dyeing machine. The dyeing method used is shown in Figure 1. The dyeing procedure consists of two experiments: 1. Dyeing with only AA, 2. Dyeing with AA+TSP. Both processes were carried out with 1% (owf) acid dyes and varied amounts of acetic acid between 0-2.3 g/L maintaining a material-to-liquor ratio at 1:10. In the second experiment, additionally, 1 g/L trisodium phosphate was used. The dyeing started at 35°C and the temperature was raised to 105°C with a degree of 2°C/min and dyeing was continued further for 50 minutes. The temperature was gradually lowered, first to 70°C and then to 45°C, to complete the dyeing process. The dyed fabrics were removed and washed by passing them through three warm water baths before being left to dry. 180 29–30 May 2025, Ljubljana, Slovenia Figure 1: Dyeing procedure 2.2.2 Measurement and Analysis The pH values of each dye bath were recorded using a REX PH310F pH meter, following the completion of the dyeing process. The amount of dye absorbed by the fabrics was measured using an X-Rite Ci7800 spectropho-tometer interfaced to a PC using D65 illumination, 10° standard observer with specular component excluded and UV component included. Each fabric was folded in half to create two layers, and the average of two readings was recorded for each measurement. 3. RESULTS AND DISCUSSION The effect of TSP on the pH of the dye bath and herewith dye adsorption of the nylon fabric were studied with two different acid dyes. One of the monosulfonated C.I Acid Blue 62 and the other is disulfonated 1:2 pre-metalized acid dye C.I Acid Blue 193. In the first experiment, two separate dyeing processes were performed using Acid Blue 62 dye. In the first pro-cess, 1 g/L TSP was added to the dye bath, while AA was introduced in varying concentrations from 0 to 2.3 g/L. Following the completion of dyeing in each bath with different AA levels, the pH of the dye bath was measured. Af-ter the nylon fabrics from each dye bath were washed and dried, the amount of dye adsorbed in the process using 1% dye was determined. In the second experiment, the same procedures were repeated using Acid Blue 193 dye. For both experiments, the pH variations of the dye baths based on the amount of AA are shown in Figure 2. In the graphs, the blue curve represents the pH change when TSP is used in addition to AA, while the red curve shows the pH change when only AA is used. As observed in both dyeing experiments, TSP prevented the sudden drop in the dye bath pH from around 9 to 4-5, ensuring a more gradual decrease instead. 181 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia A) ACID BLUE 62 ACID BLUE 62 (g/L) B) ACID BLUE 193 ACID BLUE 193 (g/L) Figure 2: The pH change of the dye bath depending on the amount of AA (MAA) considering the presence or absence of TSP AA Figure 2: The pH change of the dye bath depending on the a mount of AA (M ) considering the presence or for A) Acid Blue 62 and B) Acid Blue 193 absence of TSP for A) A cid Blue 62 and B) Acid Blue 193 The dye adsorption of nylon fabrics based on the amount of AA is presented in Figure 3 and Figure 4 for Acid The dye adsorption of nylon fabrics based on the amount of AA is presented in Figure 3 and Figure 4 for Acid Blue 62 and Acid Blue 193, respectively. As observed from the graphs, for both dyes, when only AA is used, the Blue 62 and Acid Blue 193, respectively. As observed from the graphs, for both dyes, when only AA is used, centage. When TSP is used alongside AA in the dyeing process, dye uptake occurs gradually up to a certain AA When TSP is used alongside AA in the dyeing process, dye uptake occurs gradually up to a certain AA concentration. In environments where the pH is acidic enough for the reaction to occur, a concentration. In environments where the pH is acidic enough for the reaction to occur, a significant percentage of significant percentage of the dye is gradually adsorbed by the fabric. This gradual adsorption helps prevent the dye is gradually adsorbed by the fabric. This gradual adsorption helps prevent potential dye breaks and color potential dye breaks and color inconsistencies. occurs at this stage, increasing the AA amount further does not result in a significant change in the adsorption per uptake occurs at this stage, increasing the AA amount further does not result in a significant change in the -adsorption percentage. fabric rapidly adsorbs a large portion of the dye even at very low AA concentrations. Since most of the dye uptake the fabric rapidly adsorbs a large portion of the dye even at very low AA concentrations. Since most of the dye inconsistencies. The images of the dyed fabrics in Figure 3 and Figure 4 support this observation. Images B.1 and The images of the dyed fabrics in Figure 3 and Figure 4 support this observation. Images B.1 and B.2 show the dye adsorption at AA concentrations of 0 and 2.3 g/L, B.2 show the dye adsorption at AA concentrations of 0 and 2.3 g/L, respectively, when TSP is used. Images C.1 respectively, when TSP is used. Images C.1 and C.2 show the dye adsorption at AA concentrations of 0 and and C.2 show the dye adsorption at AA concentrations of 0 and 2.3 g/L, respectively, when only AA is used. As ob-2.3 g/L, respectively, when only AA is used. As observed, when only AA is used, there is no significant served, when only AA is used, there is no significant difference in the fabric colors at the beginning and end points, difference in the fabric colors at the beginning and end points, whereas when TSP is used, it is evident that whereas when TSP is used, it is evident that less dye is adsorbed at the starting point compared to the endpoint. less dye is adsorbed at the starting point compared to the endpoint. When comparing the two dyes, it was observed that in the case of Acid Blue 193, the dye adsorption onto the When comparing the two dyes, it was observed that in the case of Acid Blue 193, the dye adsorption onto the nylon fabric was significantly lower than that of Acid Blue 62 when only AA was used. This can be explained nylon fabric was significantly lower than that of Acid Blue 62 when only AA was used. This can be explained by the by the disulfonated nature of Acid Blue 193. As the sulfonation degree of the dye increases, the fabric's ability disulfonated nature of Acid Blue 193. As the sulfonation degree of the dye increases, the fabric‘s ability to adsorb to adsorb the dye decreases (Chantler, 1969). However, this issue can be mitigated by using TSP, as clearly the dye decreases (Chantler, 1969). However, this issue can be mitigated by using TSP, as clearly shown in the shown in the graph provided in Figure 4, image A. graph provided in Figure 4, image A. 4 182 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia A) B.1) B.2) A) B.1) B.2) C.1) C.2) C.1) C.2) ACID BLUE 62 ACID BLUE 62 (g/L) (g/L) Figure 3: Figure 3: A) The change of dye adsorption of the fabrics depending on amount of AA (MAA) considering the A) The change of dye adsorption of the fabrics depending on amount of AA (MAA) considering the presence or Figure 3: A) The change of dye adsorption of the fabrics depending on amount of AA (M AA ) considering the presence or a bsence of TSP for Acid Blue 62; the dyed fabrics for the presence of 1 g/L TSP with B.1 ) no AA absence of TSP for Acid Blue 62; the dyed fabrics for the presence of 1 g/L TSP with B.1) no AA B.2) 2.3 g/L AA; the dyed presence or a bsence of TSP for Acid Blue 62; the dyed fabrics for the presence of 1 g/L TSP with B.1 ) no AA B.2 ) 2.3 g/L AA; the dyed fabrics for the absence of TSP with fabrics for the absence of TSP with C.1) no AA C.2) 2.3 g/L AA C.1) no AA C.2 ) 2.3 g/L AA B.2 ) 2.3 g/L AA; the dyed fabrics for the absence of TSP with C.1) no AA C.2 ) 2.3 g/L AA A) B.1) B.2) A) B.1) B.2) C.1) C.2) C.1) C.2) ACID BLUE 193 ACID BLUE 193 (g/L) (g/L) Figure 4: Figure 4: A) The change of dye adsorption of the fabrics depending on amount of AA (MAA) considering the Figure 4: A) The change of dye adsorption of the fabrics depending on amount of AA (M AA ) considering the presence or A) The change of dye adsorption of the fabrics depending on amount of AA (MAA) considering the presence or a bsence of TSP for Acid Blue 193; the dyed fabrics for the presence of 1 g/L TSP with B.1 ) no presence or a bsence of TSP for Acid Blue 193; the dyed fabrics for the presence of 1 g/L TSP with B.1 ) no absence of TSP for Acid Blue 193; the dyed fabrics for the presence of 1 g/L TSP with B.1) no AA B.2) 2.3 g/L AA; the dyed AA B.2 ) 2.3 g/L AA; the dyed fabrics for the absence of TSP with C.1) no AA C.2 ) 2.3 g/L AA AA B.2 ) 2.3 g/L AA; the dyed fabrics for the absence of TSP with C.1) no AA C.2 ) 2.3 g/L AA fabrics for the absence of TSP with C.1) no AA C.2) 2.3 g/L AA 4. CONCLUSIONS 4. CONCLUSIONS 4. CONCLUSIONS In this study, we propose the use of trisodium phosphate (TSP) to prevent dye breaks and color inconsistencies, In this study, we propose the use of trisodium phosphate (TSP) to prevent dye breaks and color In this study, we propose the use of trisodium phosphate (TSP) to prevent dye breaks and color inconsistencies, which are common challenges in large-scale nylon fabric dyeing. Acting as a buffering agent which are common challenges in large-scale nylon fabric dyeing. Acting as a buffering agent during the dyeing inconsistencies, which are common challenges in large-scale nylon fabric dyeing. Acting as a buffering agent during the dyeing process, TSP prevents the abrupt drop in pH from approximately 9 to the optimal range of process, TSP prevents the abrupt drop in pH from approximately 9 to the optimal range of 4–6. Instead, it ensures during the dyeing process, TSP prevents the abrupt drop in pH from approximately 9 to the optimal range of 4– 6. Instead, it ensures a gradual pH reduction, allowing the nylon fabric to progressively adsorb the dye, a gradual pH reduction, allowing the nylon fabric to progressively adsorb the dye, leading to uniform adsorption 4– 6. Instead, it ensures a gradual pH reduction, allowing the nylon fabric to progressively adsorb the dye, leading to uniform adsorption across the entire fabric surface. Furthermore, the use of TSP effectively across the entire fabric surface. Furthermore, the use of TSP effectively prevented the low adsorption rates ob-leading to uniform adsorption across the entire fabric surface. Furthermore, the use of TSP effectively prevented the low adsorption rates observed in dyeings using AA alone with 1:2 premetallized dyes containing served in dyeings using AA alone with 1:2 premetallized dyes containing disulfonated groups. By incorporating prevented the low adsorption rates observed in dyeings using AA alone with 1:2 premetallized dyes containing TSP, adsorption percentages comparable to those of monosulfonated dyes were achieved, enhancing dye uptake efficiency. 5 5 183 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Chantler, M. D., Partlett, G. A., & Whiteside, J. A. B. 1969. “Prospects and Problems in the Dyeing and Finishing of Differential₂dyeing Nylon 6.6 Yarns.” Journal of the Society of Dyers and Colourists 85 (12): 621-629. Dawson, T. L. 1981. “pH and its importance in textile coloration.” Journal of the Society of Dyers and Colourists 97 (3): 115-125. FB, L., & CK, L. 2007. “Dyeing optimization with metal complex acid dyes for nylon fabrics.” Journal of textile engineering 53 (3): 117-122. Kertess, A. F., Potts, S., HOWLETT, F., & LUXMORE, J. 1949. “The Properties and Uses of Nylon Fabrics.” Journal of the Textile Institute Proceedings 40 (4): 388-393. Kim, S. D., Lee, H. Y., Choi, Y. J., & Lee, J. L. 2011. “Dyeing characteristics of Nylon, cotton and N/C mixture fabrics with reactive-disperse dyes containing a sulphatoethylsulphone group.” Fibers and Polymers 12: 932-938. Lee, B. S., Lee, J. A., Lee, K. S., Park, J. H., & Kim, S. D. 2006. “Dyeing Properties of Nylon Fabric with Reactive Dyes Having Different Reactive Group.” Textile Coloration and Finishing 18 (5): 1-7. Maulik, S. R., Bhattacharya, A., Roy, P. P., & Maiti, K. 2022. “Reactive Dye and Its Advancements.” Textile Dyes and Pigments: A Green Chemistry Approach 17-44. Soleimani-Gorgani, A., & Taylor, J. A. 2006. “Dyeing of nylon with reactive dyes. Part 1. The effect of changes in dye structure on the dyeing of nylon with reactive dyes.” Dyes and pigments 68 (2-3): 109-117. Subramanian, D. R., Venkataraman, A., & Bhat, N. V. 1982. “Studies on Dyeing and mechanical properties of Nylon 6 filaments subjected to swelling treatments.” Journal of Applied Polymer Science 27 (11): 4149-4159. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Gaye Duman Özgür Baki̇ Research Research and Development Department Asli Textile Clothing Industry Inc. Asli Textile Clothing Industry Inc. and Development Department OSB No:2, 20330 OSB No:2, 20330 Denizli, Türkiye Denizli, Türkiye +902582691758 arge@aslitekstil.com.tr +902582691758 gaye@aslitekstil.com.tr Mert Bakirli Asli Textile Clothing Industry Inc. Research and Development Department OSB No:2, 20330 Denizli, Türkiye +902582691758 arge@aslitekstil.com.tr Güngör Durur Pamukkale University Textile Engineering Department Kinikli, Üniversite Street Pamukkale, Denizli, Türkiye +902582962000 gdurur@pau.edu.tr 184 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION COMPARISON OF INKJET PRINTING WITH REACTIVE DYES COMPARISON OF INKJET PRINTING WITH REACTIVE DYES ON COTTON FABRIC IMPREGNATED WITH ALGINATE OR ON COTTON FABRIC IMPREGNATED WITH ALGINATE OR POLYACRYLATE THICKENER POLYACRYLATE THICKENER Petra Forte Tavčer1 Petra FORTE TAVČER 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia University of Ljubljana, Faculty of Natural Sciences and Engineering Abstract: For successful inkjet printing on cotton fabric, the fabric must be pretreated. The pretreatment consists of impregnating the fabric with a thickener solution that also contains all the chemicals needed to fix the dyes to the fibres. In our study, natural alginate and synthetic polyacrylate thickeners were applied to the fabric by impregnation. The fabrics were printed using the Mimaki Tx2-1600 digital printer with the reactive dyes cyan, magenta, yellow and black. The printed fabrics were steamed normally for 10 minutes, then washed, soaped and dried. The colour values, the colour depth and the dye penetration of the printed samples were compared. It was found that printing was successful with both preparation, although the colour depth was higher with the alginate thickener. It was also confirmed that the type of thickener in the pretreatment paste had no effect on the colour fastness on washing. Key words: digital printing, reactive dyes, thickener, colour values, colour fastness. 1. INTRODUCTION Digital printing is the latest, but already fully established textile printing technology. Dyes in the form of tiny droplets of dye solutions (ink) are sprayed onto the fabric through numerous micrometer-sized nozzles (Ujiie, 2006). Reactive, disperse, acid and pigment dyes in the form of ink are used for digital textile printing. The dyes must match the textile substrate, bond physically and chemically with the fibres, fix sufficiently and have the required fastness properties. Reactive dyes are a group of dyes with brilliant shades and good fastness properties that chemically bind to textile fibres. They are most commonly used for printing on cellulose fibres and are also suitable for printing on silk, wool and polyamide (Soleimani-Gorgani, 2005). They are anionic, as one or more sulphonate groups are bound to the dye molecule (dye−SO3-). Reactive dyes can bind to the hydroxyl groups of cellulose via the reactive system and form covalent bonds under alkaline conditions, usually by nucleophilic bimolecular substitution or nucleophilic addition mechanisms (Šostar-Turk, 1998). The textile material to be printed must be prepared accordingly before printing, and the dye must be fixed, washed and dried after printing. Absorption and capillary forces in the fibres cause spreading and deteriorate the contour quality. Therefore, the fabric must be impregnated with a thickening agent and suitable fixing agents before printing. The composition of the impregnating bath and the steaming time have a strong influence on the adsorption and fixation of reactive dye on cotton (Yuen, 2005, Yang 2004). For printing on cotton, low-viscosity alginate thickeners in low concentrations are used, in which auxiliaries, oxidizing agents and alkalis are dissolved (Quiao, 2022, Eser, 2012). Some producers also recommend synthetic polyacrylate thickeners for printing of reactive dyes (Miles, 1994. Bezema, technical documentation, 2000). 1 185 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Sodium alginates are important thickeners for reactive dyes because the extent of interaction is very small. This is due to the absence of primary hydroxyl groups and to the repulsion or the dye anions by the ionised carboxyl groups of the polymer under alkaline conditions (Miles, 1994). Polyacrylate thickeners have several carboxylic acid groups which are ionised on addition of alkali. The resultant mutual repulsion of negatively charged centres causes extension of polymer chains and substantial increases in viscosity. The polyacid is usually neutralised by ammonia so that, during the drying, the free acid is largely re-formed (Figure 1) (Miles, 1994). Figure 1: Ionic and acid form of polyacrylate. After printing and drying, the dyes are fixed on the textile. During fixation, the dyes diffuse from the thickening film into the interior of the fibre and bind there. The most common fixation process is one-step normal steaming at 100–103°C. Fixation is followed by washing with cold and warm water to remove non-fixed dyes, thickeners and chemical additives (Ujiie, 2006). The aim of this study was to investigate whether reactive dyes can be digitally printed on cotton fabric pretreated with alginate or polyacrylate thickener. The CIE L*a*b* colour values, the colour depth (K/S) and the dye penetration (P) were compared on differently pretreated fabrics printed with four basic colours under the same conditions. The colour fastness of the prints to washing was also measured. 2 METHODS 2.1 Materials 100% cotton plain woven fabrics 156 g/m2 from the manufacturer Tekstina d.d. Ajdovščina, Slovenia, was used. 2.2 Preparing the textiles for printing The fabrics were pretreated with an alginate thickening preparation (A) or a polyacrylate thickening preparation (PAC). The recipes are listed in Tables 1 and 2. The following chemicals were used: CHT alginate EHV (Bezema, Switzerland), alginate thickener; Clear D/27 (Minerva, Italy), polyacrylate thickener; sodium hydrogen carbonate (NaHCO ₃) (Kemika, Zagreb, Croatia); urea (CO(NH₂)₂) (J.T. Baker, Netherlands), hydrotropic agent, Rapidoprint XR (Bezema, Switzerland), sodium m-nitrobenzenesulfonate, oxidising agent; citric acid (C ₆H₈O₇) (Kemika, Zagreb, Croatia). The fabrics were impregnated with a laboratory two-roller padder (Mathis, Switzerland) with an impregnation effect of 88 %. The impregnated samples were air dried at room temperature. 2 186 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Table 1: Recipe for the preparation of the alginate (A) and polyacrylate (PAC) thickener. Additive A Amount (g) PAC CHT-alginat EHV 4 % 400 - Clear D/27 - 26 Distilled H2O 525 889 NaHCO₃ 25 25 CO(NH₂)₂ 50 50 Rapidoprint XR 10 10 Total 1000 1000 2.3 Printing, fixation and after-treatment Printing was done with a digital piezo DOD printer TextileJet Tx2-1600 from Mimaki with a resolution of 720 dpi and reactive dyes Jettex R (DyStar, England). The patterns were pre-processed as squares in Adobe Photoshop. 100% cyan (C), 100% yellow (Y), 100% magenta (M) and 100% black (K) were printed. The printed fabrics were fixed in a laboratory steamer DHE 20675 (Werner Mathis AG, Switzerland) in 90% saturated steam at 102°C for 10 minutes. After fixation, the fabric was first rinsed with cold water to remove residual thickeners, chemicals and some unfixed dyes, then with warm water and finally with hot water. The next step was soaping for five minutes at 100 °C with 1 g/l CIBAPON R detergent (CIBA, Switzerland) to remove all remaining dye residues. After soaping, the samples were rinsed with warm and cold water and air-dried at room temperature. 2.4 Analyses The colour coordinates CIE L*a*b* and the reflectance R (%) of the printed samples were measured with a spectrophotometer SF 600 PLUS-CT (Datacolor International, Switzerland). Ten measurements were taken for each colour on each print. The measurements were taken on the front and back of the printed fabric. The measurement conditions were: standard light D65, standard observer 10°, device geometry d/8°, measuring range 400–700 nm, four fabric layers and a measuring aperture of 20 mm. The colour difference (ΔE*) was calculated from the CIE colour coordinates L*a*b* according to equation 1: ΔE*ab = (1) where ΔL* is the difference in lightness, Δa* is the difference on the red-green axis and Δb* is the difference on the yellow-blue axis. The colour depth values (K/S) of the prints were calculated from the reflectance measurements using equation 2: (2) where K is the absorption coefficient (depending on the dye concentration), S is the scattering coefficient and R is the reflectance of the sample at a specific wavelength (R = 0 – 1). The penetration coefficient, P, indicates the amount of dye that has reached the back of the fabric. It was calculated according to equation 3: (3) where K/S(front) is the colour depth on the front side of the sample and K/S(back) is the colour depth on the back side of the sample. 3 187 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Colour fastness to washing was determined according to the standard ISO 105-C01:1989 – Textiles – Colour fastness tests - Part C01: Colour fastness to washing: Test 1. The samples were washed in a Launder-ometer LDH-HT B-S (Atlas Electric Devices, USA). 3. RESULTS AND DISCUSSION Table 2 shows the results of the CIE L*a*b* colour values of cyan, magenta, yellow and black (CMYK) prints on cotton fabric impregnated with different preparations. The L*a*b* values are close although the calculated colour differences, ΔE*, show that the colours printed on differently pretreated fabrics differ significantly. Table 2: CIE L*a*b* values of CMYK prints on cotton fabrics impregnated with alginate (A) or polyacrylate (PAC) thickener and colour differences, ∆E*, between differently pretreated fabrics. Thickener Colour L* a* b* ∆E* C 51,25 -32,08 -31,87 - A M 44,9 54,32 -7,56 - Y 84,16 -5,55 90,3 - K 22,52 -5,95 -6,8 - C 52,67 -32,49 -31,97 1,48 PAC M 47,55 53,58 -8,97 3,09 Y 85,37 -4,64 87,7 3,01 K 26,33 -6,6 -7,43 3,92 Figure 2 shows that the colour depths (K/S) are higher on fabric impregnated with alginate than with acrylate thickener for all colours. 25 A PAC 20 15 K/S 10 5 0 C M Y K Colour Figure 2: K/S values of CMYK prints on cotton fabrics impregnated with alginate (A) or polyacrylate (PAC) thickener 4 188 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Figure 3 shows the degree of penetration of the CMYK colours. The values are similar at all colours. 25 20 A PAC ) 15 P (% 10 5 0 C M Y K Colour Figure 3: Penetration degree (P) of CMYK prints on cotton fabrics impregnated with alginate (A) or polyacrylate (PAC) thickener Table 3 shows the colour fastness values of the prints when washed at 60°C. The colour changes and the ratings for dye transfer to cotton and wool are good for all samples and show no difference between differently pretreated fabrics. Polyamide adjacent fabric are similar for all dyes and fabrics. The ratings range from 3 to 4-5. The staining on the adjacent fabrics is relatively low, indicating that the washed-out dye does not stain the adjacent fabrics. Table 3: Wash fastness values at 60°C of prints on cotton fabrics impregnated with alginate (A) or polyacrylate (PAC) thickener Pre-treatment Washing Fastness Colour Colour Change Staining of Cotton Staining of Wool C 4 4 3 A M 5 4 4 Y 5 4 4 K 4 4 4 C 4 4 2 PAC M 4 4 4 Y 5 4 4 K 5 4 4 4. CONCLUSIONS Cotton fabrics impregnated with polyacrylate thickener can be successfully printed digitally with reactive dyes, although the colour tones achieved are slightly lower than those obtained with cotton fabrics impregnated with alginate thickener. The colour differences are not very high, but are visible by naked eye. Penetration values are similar for both thickeners. The wash fastnesses are good in both cases. We can conclude that reactive dyes react and bind to the cotton fabric in the same way at both thickeners. The explanation for lower K/S values at PAC is its transformation into acidic form during drying. This lowers the pH value of the environment and reduces the degree of reaction of reactive dyes with cellulose. 5 189 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Eser, B., Özgüney, A. T. and Özerdem, A. 2012. “Investigation of the Usage of Different Thickening Agents in Ink-Jet Printing with Reactive Dyes.” Industria Textila 63(2): 85–90. Miles, L. W. C. 1994. Textile Printing. Society of Dyers and Colourists, Bradford, England. Qiao, X., Fang, K., Liu, X., Gong, J., Zhang, S., Wang, J. and Zhang, M. 2022. “Different Influences of Hydroxypropyl Methyl Cellulose Pretreatment on Surface Properties of Cotton and Polyamide in Inkjet Printing.” Progress in Organic Coatings 165: 1–9. Soleimani-Gorgani, A. and Taylor, J. A. 2006. “Dyeing of Nylon with Reactive Dyes. Part 1. The Effect of Changes in Dye Structure on the Dyeing of Nylon with Reactive Dyes.” Dyes and Pigments 68: 109–117. Šostar, S. and Schneider, R. 1998. “Guar Gum as an Environment-Friendly Alternative Thickener in Printing with Reactive Dyes.” Dyes and Pigments 39(4): 211–221. Ujiie, H. 2006. Digital Printing of Textiles. The Textile Institute, CRC Press, Woodhead Publishing Ltd., Cambridge, England. Yuen, C. W. M., Ku, S. K. A., Choi, P. S. R. and Kan, C. W. 2005. “Factors Affecting the Color Yield of an Ink-Jet Printed Cotton Fabric.” Textile Research Journal 75(4): 319–325. Yang, Y. and Naarani, V. 2004. “Effect of Steaming Conditions on Colour and Consistency of Ink-Jet Printed Cotton Using Reactive Dyes.” Coloration Technology 120: 127–131. Corresponding author: ADDITIONAL DATA ABOUT AUTHORS University of Ljubljana, Faculty of Natural Sciences and Engineering, Petra Forte Tavčer Aškerčeva 12, 1000 Ljubljana, Slovenia University of Ljubljana Petra FORTE TAVČER Corresponding author: petra.forte@ntf.uni-lj.si Faculty of Natural Sciences and Engineering Aškerčeva 12 1000 Ljubljana, Slovenia petra.forte@ntf.uni-lj.si 6 190 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION TRIALS OF DRY-AIR FIXATION OF DIGITALLY PRINTED REACTIVE DYES ON COTTON FABRICS Petra Forte Tavčer1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The possibility of dry-air fixation of reactive dyes on textile substrates was investigated. The fabrics were impregnated with an alkaline solution of alginate thickener containing different amount of urea. The objective was to determine the optimal pretreatment for achieving high-quality prints. The fabrics were printed in the primary colours; cyan, magenta, yellow, black and subsequently analysed for colour depth (K/S), CIELAB colour values, and print sharpness. Additionally, the colour fastnesses of the prints to washing, rubbing (crock test), and light were measured. The results indicated that steam fixation provides significantly better print quality, demonstrating that dry-air fixation is insufficient for optimal results in digital printing with reactive dyes. An increased amount of urea in the pretreatment improved printing results in certain cases. Key words: digital textile printing, reactive dyes, dry‐air fixation, mercerized cotton, colour fastness. 1. INTRODUCTION Cotton fabrics can be digitally printed with pigments or reactive dyes (Miles, 1994). Because inks are non-vis-cous water solutions, they easily spread along fibres as a consequence of capillary forces, compromising the sharpness of contours. To prevent this, the fabric should be treated with a thickening agent and appropriate fixing agents before printing. For printing on cotton, low-viscosity alginate thickeners in low concentrations are used, in which auxiliaries, oxidizing agents, and alkalis are dissolved (Qiao, 2022; Eser, 2012). After printing, the dye must undergo fixation, washing, and drying. During fixation, the dyes diffuse from the thickening film into the interior of the fibre and bind there. The most common fixation process is one-step normal steaming at 100–103°C. Fixation is followed by washing with cold and warm water to remove non-fixed dyes, thickeners, and chemical additives (Ujiie, 2006). The composition of the impregnating bath and the steaming time have a strong influence on the adsorption and fixation of reactive dye on cotton (Yuen, 2005; Yang, 2004; Hamaky, 2007). Experiments on the fixation of reactive dyes with dry heat have also been published (Yasukawa et al., 2008). Since steamers are not available in many places where digital printing is performed, we were interested in whether cotton samples digitally printed with reactive dyes could be fixed using dry heat, i.e., without the use of a steamer Standard inks from a selected manufacturer were used. The fabric was pretreated with finishes containing dif-ferent concentrations of urea, which increases the possibility of dye reactions with fibers during dry heat fixation. The CIE L*a*b* colour values, the colour depth (K/S) were compared on fabrics printed with four basic colours and differently fixed. The colour fastness of the prints to washing, light and rubbing was also measured. 2. METHODS 2.1 Materials Singed, desized, scoured, bleached and mercerized 100% cotton plain fabrics 156 g/m2 from the manufacturer Tekstina d.d. Ajdovščina, Slovenia, was used. 2.2 Preparing the textiles for printing Three alginate thickening pretreatment solutions with different concentration of urea were prepared. The recipes are presented in Table 1. 191 29–30 May 2025, Ljubljana, Slovenia The following chemicals were used: CHT alginate EHV (Bezema, Switzerland), alginate thickener; sodium hy-drogen carbonate (NaHCO₃) (Kemika, Zagreb, Croatia); urea (CO(NH₂)₂) (J.T. Baker, Netherlands), hydrotropic agent, Rapidoprint XR (Bezema, Switzerland), sodium m-nitrobenzenesulfonate, oxidising agent. The pretreatment solutions were padded onto cotton fabircs using a laboratory two-roller padder (Mathis, Switzer-land) with a pick-up of 75%. The pretreated samples were air dried at room temperature. Table 1: Recipe for the alginate pretreatments. Additive A1 Amount [g] A2 A3 CHT-alginat EHV 4 % 400 400 400 CO(NH₂)₂ 50 100 150 Rapidoprint XR 10 10 10 NaHCO 26 26 26 3 Distilled H O 514 464 414 2 Total 1000 1000 1000 2.3 Printing, fixation and after-treatment Printing was performed using a digital piezo DOD printer TextileJet Tx2-1600 from Mimaki with a resolution of 720 dpi and reactive dyes Jettex R (DyStar, England). The patterns were printed as squares of 10x10 cm and lines of 1 mm. 100% cyan (C), 100% yellow (Y), 100% magenta (M) and 100% black (K) were printed. The printed fabrics were fixed in a laboratory steamer DHE 20675 (Werner Mathis AG, Switzerland) in 90% sat-urated steam at 102°C for 10 minutes or in a stenter dryer (W. Mathis AG, Switzerland) for 5 minutes at 150 °C. After fixation, the fabrics were first rinsed with cold water to remove residual thickeners, chemicals and some unfixed dyes, then with warm water and finally with hot water. The next step was soaping for five minutes at 100 °C with 1 g/l CIBAPON R detergent (CIBA, Switzerland) to remove all remaining dye residues. After soaping, the samples were rinsed with warm and cold water and air-dried at room temperature. 2.4 Analyses The colour coordinates CIE L*a*b* and the reflectance R (%) of the printed samples were measured with a spectrophotometer SF 600 PLUS-CT (Datacolor International, Switzerland). Ten measurements were taken for each colour on each print. The measurement conditions were: Standard light D65, standard observer 10°, device geometry d/8°, measuring range 400–700 nm, four fabric layers and a measuring aperture of 20 mm. The colour difference (ΔE*) was calculated from the CIE colour coordinates L*a*b* according to equation 1: ΔE* = (1) ab where ΔL* is the difference in lightness, Δa* is the difference on the red-green axis and Δb* is the difference on the yellow-blue axis. 192 29–30 May 2025, Ljubljana, Slovenia The colour depth values (K/S) of the prints were calculated from the reflectance measurements using equation 2: (2) where K is the absorption coefficient (depending on the dye concentration), S is the scattering coefficient and R is the reflectance of the sample at a specific wavelength (R = 0 – 1). Colour fastness to washing at 40 °C was determined according to the standard ISO 105-C01:1989 – Textiles – Colour fastness tests - Part C01: Colour fastness to washing: Test 1. The samples were washed in a Launder-ometer LDH-HT B-S (Atlas Electric Devices, USA). Light fastness was determined according to the standard SIST EN ISO 105-B02:2014 – Colour fastness to artificial light: Xenon arc lamp test on a Xenotest Alpha (Atlas, USA). Rub fastness was determined according to the standard SIST EN ISO 105-X12:2002 – Colour fastness to rubbing. Rubbing was carried out using a Crockmeter (Electronic Crockmeter; SDL Atlas, USA) 3. RESULTS AND DISCUSSION Table 2 shows the results of the CIE L*a*b* colour values of CMYK prints on cotton fabric impregnated with dif-ferent preparations. Figure 1 represents the K/S values of printed samples. Colour differences show that colors vary the most depending on the fixation method. Samples fixed with steam have lower lightness (L*) and higher a* and b* values than samples fixed with dry air. This means that significantly less dye bonded to the fabric with hot air treatment than with steam. The unbound, printed dyes were removed during washing and fixation. The colour differences between steam-fixed and dry-air-fixed samples are very large and visible to the naked eye. This is also confirmed by the K/S values (Figure 1), which indicate the colour depth. For all steamed samples, the values are much higher than for those treated with dry air. The type of pretreatment has a much smaller effect on colours than the fixation method. With an increasing con-centration of urea, the K/S values rise for C, M and Y. For K, however, the K/S values are highest with the A2 finish, which has a medium urea concentration. 193 29–30 May 2025, Ljubljana, Slovenia Table 2: CIE L*a*b* values of prints and colour differences (ΔE*) between steamed prints on preparation A1. Colour Fixation Pre-treat- L* a* b* ΔE* ment steam A1 58,15 -28,69 -24,38 A2 55,21 -30,72 -26,04 3,94 A3 55,27 -32,01 -26,63 4,94 C dry air A1 77,5 -14,68 -5,69 30,33 A2 76,9 -15,87 -6,77 28,74 A3 76,48 -17,53 -8,13 26,92 steam A1 54,16 50,46 -0,9 A2 53,91 50,95 -1,35 0,71 A3 54,09 52,97 -1,9 2,71 M dry air A1 74,39 22,47 -1,95 34,55 A2 73 24,81 -2,92 31,89 A3 72,93 26,42 -2,58 30,55 steam A1 81,17 2,51 78,23 A2 79,61 2,77 75,03 3,58 A3 80,84 3,98 76,56 2,25 Y dry air A1 84,26 -6,03 52,56 27,24 A2 84,39 -6,24 60,6 19,94 A3 84,28 -5,4 60,21 19,92 steam A1 22,5 -0,84 -1,97 A2 20,28 -1,09 -1,81 2,25 A3 20,92 -1,15 -1,93 1,61 K dry air A1 30,83 -4,83 -2,53 9,25 A2 24,91 -3,56 -2,06 3,6429–30 May 2025, Ljubljana, Slovenia A3 26,96 -3,84 -1,7 5,38 20,00 18,00 steam hot air 16,00 14,00 12,00 K/S 10,00 8,00 6,00 4,00 2,00 0,00 A1 A2 A3 A1 A2 A3 A1 A2 A3 A1 A2 A3 cyan magenta yellow key Pretreatment/Colour Figure 1: K/S values of printed samples impregnated with A1, A2 or A3 preparation, fixed in steam or dry air. Figure 1: K/S values of printed samples impregnated with A1, A2 or A3 preparation, fixed in steam or dry air. Table 3 lists the measured line thickness values, illustrating the printing accuracy on the examined samples. In the case of steam fixation, the line widths are slightly larger than desired, while with dry-air fixation, they are equal to or less than 1 mm. The largest deviation is observed in the sample pretreated with A3 and steamed, exceeding the expected width by 0.4 mm. 194 Table 3: Width of a 1 mm line printed on differently pretreated and fixed fabrics with magenta 29–30 May 2025, Ljubljana, Slovenia Table 3 lists the measured line thickness values, illustrating the printing accuracy on the examined samples. In the case of steam fixation, the line widths are slightly larger than desired, while with dry-air fixation, they are equal to or less than 1 mm. The largest deviation is observed in the sample pretreated with A3 and steamed, exceeding the expected width by 0.4 mm. Table 3: Width of a 1 mm line printed on differently pretreated and fixed fabrics with magenta Fixation Pre-treatment Line width [mm] A1 1,2 Steam A2 1,2 A3 1,4 A1 1,2 Dry air A2 0,9 A3 1 Table 4 presents the ratings of colour tone changes in the samples, and of colour transfer to cotton (Co) and wool (Wo), both measured after washing at 40 °C. Table 5 includes the ratings of colour fastness of the prints to dry and wet rubbing, as well as the assessments of colour fastness to light exposure. At colour fastness to washing at 40 °C both the ratings for colour tone changes and the ratings for colour transfer to cotton and wool were good, ranging between values 4 and 5. The colour fastness ratings of prints to dry and wet rubbing are similar for both dry-air and steam fixation. Better results were observed for yellow samples, while cyan and black samples performed worse, as expected, since darker shades are more visible than lighter ones. The colour fastness ratings of prints to light clearly show that the values are significantly lower for dry-air-fixed samples compared to steam-fixed ones. This is because, with a smaller amount of dye on the fibres, any degra-dation due to light exposure is more noticeable. Slightly poorer results were observed for samples pretreated with A3. 195 29–30 May 2025, Ljubljana, Slovenia Table 4: Wash fastness values of samples printed on different preparation and fixed with steam or dry air. Washing fastness Colour Fixation Pre-treatment Colour change Staining CO Staining Wo A1 / 4 5 steam A2 4/5 4 5 A3 4/5 4 5 C A1 5 5 5 dry air A2 5 5 5 A3 4/5 5 5 A1 5 5 5 steam A2 4/5 5 5 A3 5 5 5 M A1 5 5 5 dry air A2 5 5 5 A3 5 5 5 A1 5 5 5 steam A2 5 5 5 A3 5 5 5 Y A1 5 5 5 dry air A2 5 5 5 A3 5 5 5 A1 5 4 5 steam A2 4/5 4 5 A3 5 4/5 5 K A1 5 4/5 5 dry air A2 5 5 5 A3 5 4/5 5 196 29–30 May 2025, Ljubljana, Slovenia Table 5: Colour fastness values to wet and dry rubbing and light. Colour fastness Colour Fixation Pre-treatment Dry rubbing Wet rubbing Light A1 2 3/4 4 steam A2 1/2 4/5 5 A3 1/2 4/5 5 C A1 4 4/5 1 dry air A2 4/5 5 2 A3 4 4 2 A1 2 4/5 3 steam A2 4/5 4/5 4 A3 3 4/5 4 M A1 4 4/5 1 dry air A2 4/5 3/4 1 A3 3 4 1 A1 3 4/5 5 steam A2 5 4/5 5 A3 3 4/5 4 Y A1 5 4/5 2 dry air A2 3 4/5 2 A3 3/4 4/5 2 A1 3 5 4 steam A2 2 4/5 4 A3 1/2 4/5 4 K A1 4 4/5 3 dry air A2 1/2 4/5 3 A3 3 4/5 3 4. CONCLUSIONS The investigation revealed that in digital printing with reactive dyes, fixation cannot be achieved with dry air, as the samples appear too light, the color depth is low, and fastness, especially to light and rubbing, is poor. Dye migration into the fibers is minimal in the absence of moisture, resulting in less dye reacting with the fibres. Even an increased amount of urea in the preparation is not sufficient to achieve adequate fibre dyeing in dry conditions. Moreover, a higher urea concentration negatively affects print accuracy at steaming. 197 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES El Hamaky, Y. H., Tawfeek, S., and Gaber, S. 2007. “Printing Cotton Fabrics with Reactive Dyes of High Reactivity from an Acidic Printing Paste.” Coloration Technology 123(6): 365–373. Miles, L. W. C. 1994. “Textile Printing.” In Textile Printing, edited by L. W. C. Miles, Bradford: Society of Dyers and Colourists. Qiao, X., Fang, K., Liu, X., Gong, J., Zhang, S., Wang, J., and Zhang, M. 2022. “Different Influences of Hydroxypropyl Methyl Cellulose Pretreatment on Surface Properties of Cotton and Polyamide in Inkjet Printing.” Progress in Organic Coatings 165: 1–9. Ujiie, H. 2006. “Digital Printing of Textiles.” In Digital Printing of Textiles, edited by H. Ujiie, Cambridge: The Textile Institute, CRC Press, Woodhead Publishing Ltd. Yang, Y., and Naarani, V. 2004. “Effect of Steaming Conditions on Colour and Consistency of Ink-Jet Printed Cotton Using Reactive Dyes.” Coloration Technology 120: 127–131. Yasukawa, R. 2008. “Dye Fixation Process in Ink-Jet Printing of Cotton Fabric by Reactive Dye.” Sen-I Gakkaishi 64(5): AA113–AA117. Yuen, C. W. M., Ku, S. K. A., Choi, P. S. R., and Kan, C. W. 2005. “Factors Affecting the Color Yield of an Ink-Jet Printed Cotton Fabric.” Textile Research Journal 75(4): 319–325. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Petra Forte Tavčer University of Ljubljana Faculty of Natural Sciences and Engineering Aškerčeva 12, 1000 Ljubljana, Slovenia petra.forte@ntf.uni-lj.si 198 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION COLOURFASTNESS PROPERTIES OF DIGITALLY PRINTED PIGMENTS ON COTTON/LYCRA KNITTED FABRIC Mateja Kert1, Egzona Rukovci1 and Petra Eva Forte Tavčer1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The study investigated the colour fastness properties of digitally printed pigments on white and black cotton/Lycra knitted fabric. Four process colours, namely cyan, magenta, yellow and black, were printed on white fabric, while white and then cyan, magenta and yellow were printed on black fabric. The Epson SureColor F2200 inkjet printer was used for printing. After printing, samples were air-dried and cured using a hot press. The colour of the printed samples was evaluated spectrophotometrically using the CIELAB colour space. The colour fast-ness of the printed samples to rubbing, washing, hot pressing, perspiration and light was tested according to the applicable SIST EN ISO standards and visually evaluated using a grey scale and a blue wool scale, respectively. The results showed that the background colour (white or black) of the knitted fabric influenced the colour of the printed samples. The influence was more pronounced with black fabric than with white fabric. In general, the prin-ted samples had excellent colour fastness to light, very good to excellent colour fastness to washing, hot pressing and perspiration and slightly lower colour fastness to rubbing. Keywords: digital printing, pigments, cotton/Lycra knitted fabric, colour fastness. 1. INTRODUCTION Textile printing has undergone significant changes over the centuries, from outdated analogue processes (Miles, 2003) to modern digital processes (Tyler, 2005). Although rotary and flat screen printing are still the leading print-ing techniques, they have been largely superseded by digital printing in recent years. Digital printing is based on a combination of creative innovation, environmental efforts and technical improvements that allow companies to be flexible and meet the demands of a rapidly evolving market with speed and accuracy, while remaining true to their commitment to environmental responsibility. Digital textile printers enable designers and manufacturers to produce high-quality prints with vibrant colours, sharp details and smooth transitions. A focus on sustainability, customisation and digital innovation are the trends that will be responsible for the next wave of growth in the textile industry. Growing consumer awareness and high consumer expectations will translate into more environmentally friendly products (Global textile times, 2025). The digital textile printing market is forecast to reach USD 7.46 bil-lion by 2030, with a compound annual growth rate (CAGR) of 12.4% over the period 2024-2030 (Industry ARC, 2025). A detailed review of the available literature revealed that disperse, reactive and acid dyes as well as pigments are predominantly used in digital printing (Thakker, 2024). The colour fastness of printed textiles depends on both the concentration of the dye or pigment in the printing inks and the printed textiles (Glogar, 2022) and the presence of suitable chemicals on the pretreated textiles (Ding, 2021), which are responsible for the swelling of the textiles and the rapid penetration of the dye into the fibres (Kan, 2012), the formation of the dye-fibre bond and its strength during the fixing process. In addition, the appropriate post-treatment process is determined by the removal of un-fixed dye from the textiles and thus the improvement of the wet fastness properties of the printed textiles. No study was found in the published articles investigating the most common colour fastness properties on white and black knitted fabrics digitally printed with pigments. The aim of this study is therefore to investigate the colour fastness of cotton/Lycra blended knitted fabrics printed with four process colours, namely yellow, magenta, cyan, black and additionally white, whereby the results obtained can serve as a recommendation for the design of printed products according to customer requirements. 199 29–30 May 2025, Ljubljana, Slovenia The white and black knitted fabrics were digitally printed using an Epson SureColor F2200 inkjet printer. The colour fastness tests were carried out in accordance with the applicable SIST EN ISO standards. The colour fastness was tested during rubbing, washing, hot pressing, perspiration and lighting. The colour of the prints was evaluated spectrophotometrically using the CIELAB colour space. For black knitted fabric, the influence of the white pigment on the CIELAB colour values of the process colours was also evaluated by determining the colour difference. 2. EXPERIMENTAL 2.1 Knitted fabrics White (W) and black (B) single jersey knitted fabric made of 90 % cotton and 10 % elastane (Lycra) with a density of 32 (W fabric) or 31 (B fabric) wales/cm and 30 (W fabric) or 28 (B fabric) courses/cm. The W fabric has 151 g/ m2 and the B fabric 208 g/m2. 2.2 Pigment inks and chemicals Epson Ultrachrome DG2 cyan (C), magenta (M), yellow (Y), black (K) and white inks were used for printing. The inks are aqueous dispersions of pigments. When printing on dark textiles, the fabric was pre-treated with an aque-ous solution of a commercial product T43R1/SC6PTL2 (Epson, USA). 2.3 Preparation of the fabric for printing and printing Before printing, both the W and B fabrics were washed with 3 g/l anionic washing and wetting agent Subitol AS 6 (CHT, Switzerland) and 2 g/l Na CO (Honeywell, Germany) at 60 °C for 30 minutes at a ratio of LR 1:20. After 2 3 washing, the knitted fabrics were rinsed with warm and cold water and air-dried at room temperature. The B fabric samples were sprayed with the above-mentioned commercial product in a Pretreat maker 5 device (Gröner Schulze, Germany) before printing. The samples were then dried in a vacuum press at 170 °C for 60 seconds. The digital artwork was created in Adobe Illustrator 2024 and opened in the Digital Factory Apparel v11 programme with a resolution of 300 dpi. Using the Job colour replacement function, the CMYK values for each process colour C, M, Y and K were set to 100 before printing. The prepared artwork was digitally printed on white and pre-treated B samples using an Epson SC-F2200 (Epson, USA) printer. The B samples were first printed with white ink and then with CMYK inks, whereby 90% coverage of the B sample with white ink was selected. The print-ed samples were then hot-pressed at 170 °C for 60 seconds. Colour fastness tests were carried out after 3 days. The sample codes are listed in Table 1. Table 1: Sample codes and their description Sample code Description W and B white (W) and black (B) knitted fabric, unprinted W_C white knitted fabric, printed with 100 % cyan ink W_M white knitted fabric, printed with 100 % magenta ink W_Y white knitted fabric, printed with 100 % yellow ink W_K white knitted fabric, printed with 100 % black ink B_C black knitted fabric, printed with 100 % cyan ink B_M black knitted fabric, printed with 100 % magenta ink B_Y black knitted fabric, printed with 100 % yellow ink 200 29–30 May 2025, Ljubljana, Slovenia 2.4 Test methods Measurement of colour The colour of the printed samples was evaluated spectrophotometrically with the Datacolor Spectro 1050 (Data-color, USA) using the CIELAB colour space. For each sample, 10 measurements were taken at standard illumi-29–30 May 2025, Ljubljana, Slovenia nant D65, geometry d/8°, including specular reflection, 10° standard observer, 100% UV and an aperture size of 9 mm. The measurements were carried out on samples folded four times. The results represent the average value of 10 measurements. The colour difference (ΔE* ) was calculated according to equation 1: ab ∆𝐸𝐸𝐸𝐸 ∗ ∗ ∗ 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 = � ( 𝐿𝐿𝐿𝐿 2 ∗ ∗ 𝑎𝑎𝑎𝑎 − 𝐿𝐿𝐿𝐿 𝑠𝑠𝑠𝑠 ) + ( 𝑎𝑎𝑎𝑎 2 𝑎𝑎𝑎𝑎 − 𝑎𝑎𝑎𝑎 ∗ 2 𝑠𝑠𝑠𝑠 ) + ( 𝑏𝑏𝑏𝑏 (1) 𝑎𝑎𝑎𝑎 − 𝑏𝑏𝑏𝑏 ∗ 𝑠𝑠𝑠𝑠 ) where L* is the lightness, a* is the red-green axis, b* is the yellow-blue axis, the index b is the batch (B sample) where L* is the lightness, a* is the red-green axis, b* is the yellow-blue axis, the index b is the batch (B sample) and the index s is the standard (W sample). and the index s is the standard (W sample). Colour fastness to rubbing The rub fastness of the printed samples was tested in accordance with the SIST EN ISO 105-X12:2016 Colour fastness to rubbing standard using the Crockmeter M238BB (SDL Atlas, USA). The staining of wet or dry adjacent fabrics was visually assessed using a grey scale according to the SIST EN ISO 105-A03:2019 standard, with a grade of 5 The rub fastness of the printed samples was tested in accordance with the SIST EN ISO 105-X12:2016 stan indicating excellent colour fastness and a grade of 1 indicating poor colour fastness. Three repetitions of the -dard using the Crockmeter M238BB (SDL Atlas, USA). The staining of wet or dry adjacent fabrics was visually test were carried out for each sample. The result represents the average value. assessed using a grey scale according to the SIST EN ISO 105-A03:2019 standard, with a grade of 5 indicating excellent colour fastness and a grade of 1 indicating poor colour fastness. Three repetitions of the test were car Colour fastness to washing -ried out for each sample. The result represents the average value. The colour fastness of the printed samples for household and commercial laundry was tested in the GyroWash device (James Heal, UK) in accordance with the SIST EN ISO 105-C06:2012 standard using test method A1S. Colour fastness to washing Colour change was assessed visually using a grey scale (standard SIST EN ISO 105-A02:1993), while staining The colour fastness of the printed samples for household and commercial laundry was tested in the GyroWash carried out for each sample. The result represents the average value. was also assessed visually using a grey scale (SIST EN ISO 105-A03:2019). Three repetitions of the test were device (James Heal, UK) in accordance with the SIST EN ISO 105-C06:2012 standard using test method A1S. Colour change was assessed visually using a grey scale (standard SIST EN ISO 105-A02:1993), while staining Colour fastness to hot pressing was also assessed visually using a grey scale (SIST EN ISO 105-A03:2019). Three repetitions of the test were The colour fastness of the printed samples during hot pressing was tested according to the SIST EN ISO 105-carried out for each sample. The result represents the average value. X11:1999 standard. The test samples were pressed for 15 seconds at 150 °C using a hot press. The colour Colour fastness to hot pressing change and staining of white wet and white dry fabrics were visually assessed using a grey scale (standards SIST EN ISO 105-A02:1993 and SIST EN ISO 105-A03:2019) Three repetitions of the test were performed for The colour fastness of the printed samples during hot pressing was tested according to the SIST EN ISO 105-each sample. The result represents the average value. change and staining of white wet and white dry fabrics were visually assessed using a grey scale (standards SIST Colour fastness to perspiration X11:1999 standard. The test samples were pressed for 15 seconds at 150 °C using a hot press. The colour EN ISO 105-A02:1993 and SIST EN ISO 105-A03:2019) Three repetitions of the test were performed for each The colour fastness of the printed samples during hot pressing was tested according to the SIST EN ISO 105-E04:2013 standard. The test samples were pressed for 15 seconds at 150 °C using a hot press. The colour sample. The result represents the average value. change and staining of adjacent fabrics were visually assessed using a grey scale (standards SIST EN ISO Colour fastness to perspiration 105-A02:1993 and SIST EN ISO 105-A03:2019) Three repetitions of the test were performed for each sample. The result represents the average value. The colour fastness of the printed samples during hot pressing was tested according to the SIST EN ISO 105-E04:2013 standard. The test samples were pressed for 15 seconds at 150 °C using a hot press. The colour Colour fastness to artificial light change and staining of adjacent fabrics were visually assessed using a grey scale (standards SIST EN ISO 105-The colour fastness of the printed samples after a certain period of exposure to artificial light was tested in A02:1993 and SIST EN ISO 105-A03:2019) Three repetitions of the test were performed for each sample. The accordance with the SIST EN ISO 105-B02:2014 standard. The colour change was assessed visually using a result represents the average value. blue wool scale, with a grade of 8 indicating excellent light fastness and a grade of 1 indicating poor light fastness. Colour fastness to artificial light The colour fastness of the printed samples after a certain period of exposure to artificial light was tested in accor Microscopy -The uniformity of the surface of printed samples was observed under the SMZ800 stereomicroscope (Nikon, dance with the SIST EN ISO 105-B02:2014 standard. The colour change was assessed visually using a blue wool Japan) at 50x magnification. In addition, the morphology of the thickening layer of the printed samples was scale, with a grade of 8 indicating excellent light fastness and a grade of 1 indicating poor light fastness. analysed using the scanning electron microscope (SEM) JSM − 6060 LV (JEOL, Japan) at 500x magnification. Microscopy The uniformity of the surface of printed samples was observed under the SMZ800 stereomicroscope (Nikon, Ja 3. RESULTS AND DISCUSSION - pan) at 50x magnification. In addition, the morphology of the thickening layer of the printed samples was analysed 3.1. Colour using the scanning electron microscope (SEM) JSM − 6060 LV (JEOL, Japan) at 500x magnification. Table 2 shows the CIELAB values of the unprinted and printed samples of W and B fabrics. It can be seen that the difference between the colours printed on samples of W and B fabrics is quite large. Although the samples of the B fabric are covered with a layer of white pigment before the other colour pigments are printed, all colours on the samples of the W fabric are lighter than on the B fabric. This is due to the transparency of 201 the pigment system, which cannot completely cover the background colour of the fabric. In addition, a strong visual appearance of the concentrated white pigment on the fabric surface was observed on the B printed samples (see appearance of samples in Table 2), although the white ink cartridges were shaken well before 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS AND DISCUSSION 3.1 Colour Table 2 shows the CIELAB values of the unprinted and printed samples of W and B fabrics. It can be seen that the difference between the colours printed on samples of W and B fabrics is quite large. Although the samples of the B fabric are covered with a layer of white pigment before the other colour pigments are printed, all colours on the samples of the W fabric are lighter than on the B fabric. This is due to the transparency of the pigment system, which cannot completely cover the background colour of the fabric. In addition, a strong visual appearance of the concentrated white pigment on the fabric surface was observed on the B printed samples (see appearance of samples in Table 2), although the white ink cartridges were shaken well before printing, as were the coloured inks. This uneven deposition of the white pigment also affects the colour of the pigment. When calculating the colour difference between the printed fabrics W and B for each process colour, it can be seen that the largest colour difference exists for the Y pigment (∆E* = 16.59) and the smallest for the C pigment. (∆E* = 8.70). The latter is ab ab understandable as the Y pigment is the lightest and the C pigment the darkest. Table 2 also shows that the bright-ness of sample B_Y is lower compared to sample W_Y, even though the white pigment was applied to the B fabric before the Y pigment was printed. This indicates that the black colour of the fabric is most likely to show through in the printed areas. The B_Y sample is also greener and less yellow than the W_Y sample, which is also due to the black background colour of the fabric, which allows both layers of colour, white and yellow, to show through. The background colour of the knitted fabric can also be seen in samples B_C and B_M. Sample B_C is darker and less green and less blue than sample W_C, while sample B_M is darker, less red and less blue than sample W_M. Table 2: CIELAB colour values of unprinted and printed samples as well as the calculated colour difference (∆E* ) between the colours C, M and Y on samples of W and B fabrics ab Sample name Sample appear- CIE L* CIE a* CIE b* ΔE*ab ance / W 96.15 3.42 -12.31 / W_C 51.11 -13.68 -42.15 / W_M 55.43 53.98 -14.40 / W_Y 87.15 2.85 77.08 / W_K 32.21 2.03 -2.68 / B 15.09 -0.56 -0.79 8.70 B_C 44.91 -12.41 -36.18 12.56 B_M 46.90 47.49 -7.85 16.59 B_Y 75.26 -2.92 67.05 202 29–30 May 2025, Ljubljana, Slovenia A more detailed effect of the white pigment on the shade of colour pigment was investigated under stereo micro-scope. It can be seen from the appearance of samples, presented in Table 2, that the W samples are visually uni-formly printed and that the coverage of the background colour of the knitted fabric by the pigment is good. Empty spaces can also be seen between the rows and columns of the knitted fabric, which indicates that the fabric is still sufficiently permeable to air despite being printed with pigments. The latter is confirmed by SEM micrographs (Figure 1). Figure 1: SEM micrographs of W_C sample (left) and B_C sample (right) The SEM micrographs of the W_C and B_C samples presented in Figure 1 show that the fibres of the B_C sample are fully covered and bonded with a binder layer in which the pigments are entrapped, whereas in the case of the W_C sample there is significantly less binder layer formed, as W samples were not sprayed with a pre-treatment agent before printing, as was the case with the B samples. 3.2 Colour fastness Table 3 summarises the assessments of the colour fastness of the printed samples to rubbing, washing, hot press-ing, perspiration and light. Table 3: Colour fastness grades of printed samples Sam- Fastness grade ple Rubbing Wash- Hot Perspiration Light ing press- ing Dry Wet Acidic Alkaline CC_W CC_C CC_W CC_C SC SW CC SC SW CC SC SW CC SC SW CC CC W_C 3 3 3 4 4/5 4/5 5 5 5 5 5 5 5 5 5 5 8 W_M 3 3/4 3 4 4/5 4/5 5 4/5 5 5 5 5 5 5 5 5 8 W_Y 4 4 4 4 4/5 4/5 5 5 5 5 5 5 5 5 5 5 8 W_K 5 4/5 4/5 4/5 4/5 4/5 4/5 5 5 5 5 4/5 5 5 5 5 8 B_C 4 4 4 4 4/5 4/5 5 5 5 4/5 4 4 5 4 4/5 5 8 B_M 4 4/5 4/5 4 4/5 4/5 4/5 5 5 5 4/5 4 5 4 4/5 5 8 B_Y 3 3 4/5 4/5 4/5 4/5 5 5 5 5 4/5 4/5 5 4 4/5 4 8 CC_W change in colour along the length of the knitted fabric, CC_C-change in colour across the width of the knitted fabric, SC-staining of cotton fabric, SW-staining of wool fabric, CC-change in colour In general, the printed samples are less colourfast when rubbed dry than when rubbed wet, both along the length and across the width of the fabric. The fastness of W samples is also worse than that of B ones, regardless of the type of rubbing. It can be concluded from this that during rubbing, more friction occurs between the dry knitted fabric and the dry fabric with which the knitted fabric is rubbed than between the dry knitted fabric and the wet fabric. The higher colour fastness of the B printed samples during rubbing compared to the W printed samples 203 29–30 May 2025, Ljubljana, Slovenia was attributed to the fact that the B samples were additionally sprayed with an aqueous solution of a binding agent that could improve the fastness. Although the colour fastness of the printed fabrics during rubbing is between 3 and 4/5 on a grey scale, the printed samples exhibit good to very good colour fastness during dry and wet rubbing. Printed samples have excellent (grade 5) to very good (grade 4/5) colour fastness when washed at 40 °C (Table 3). No colour change (grade 5) or only a slight colour change (grade 4/5) was observed on the washed printed samples compared to the unwashed printed samples. The latter indicates that the pigments are well bonded to the binder layer formed on the cotton fibres in which the pigments are entrapped, or that the adhesion between the binder and the textile fibre is high. SEM micrographs of unwashed printed samples show that fibre adhesion and the formation of a bonding layer is much higher in B printed samples than W printed samples (Figure 1). Fur-thermore, the printed samples show excellent colour resistant to hot pressing (Table 3), with grey scale grade of 5 in almost all cases. In contrast to the colour fastness grades of the printed samples to hot pressing, the colour fastness grades of printed samples to acid and alkaline perspiration are slightly lower (grades 4 and 4/5). The printed B samples (grade 4 and 4/5) were slightly less colour resistant to acid and alkaline sweat than the printed W samples (rating 5). The latter could be attributed to the poorer colour fastness of the black dye with which the knitted fabric was dyed, which resulted in a detectable staining of white adjacent fabric during testing, whereas no pigment passage to white adjacent fabric could be detectable by naked eye. Moreover, printed samples showed excellent colour fastness to light (grade 8 according to blue wool scale) 4. CONSLUSION In the study, W and B knitted fabrics were digitally printed using an Epson SC-F2200 printer. It was found that the background colour of the fabric influenced the CIELAB values of the printed samples. As the white ink does not completely cover the background colour of the B knitted fabric, there are colour differences between the printed W and B samples. The printed samples have good to very good colour fastness when wet rubbed and less good colour fastness when dry rubbed. They have very good to excellent colour fastness to washing and hot pressing. The B samples are less fast to perspiration than the W samples, which is due to the lower colour fastness of the black dye used to dye the B samples. Both samples have excellent colour fastness to light. 5. REFERENCES Ding Y., Zhendong W., Chuanxiong Z., Ruobai X., Wenliang X. 2021. A study on the applicability of pigment digital printing on cotton fabrics. Textile Research Journal 91(19–20): 2283–2293. Global textile times: 2025 Fabric Printing: Advancements In Textile Technology, Global textile times. URL: https://www.globaltextiletimes. com/opinions/2025-fabric-printing-advancements-in-textile-technology/ (last accessed on 31.1.2025). Glogar M. I., Dekanić, T., Tarbuk A., Čorak I., Labazan P. 2022. Influence of Cotton Cationization on Pigment Layer Characteristics in Digital Printing. Molecules 27(4)1418: 1–14. Industry ARC: Digital textile printing market overview, URL: https://www.industryarc.com/Research/Digital-Textile-Printing-Market-Research-501687 (last accessed 31.1.2025). Kan, C.W, Yuen, C.W.M. 2012. Digital Ink-jet Printing on Textiles. Research Journal of Textile and Apparel 16(2): 1–24. Miles, L. W. C, 2003. Textile printing: revised second edition. Bradford: Society of Dyers and Colourists. Thakker A. M., Sun, D. 2024. Inks for digital printing of textiles. The Journal of The Textile Institute 115(12): 2377–2390. Tyler, D.J. 2005. Textile Digital Printing Technologies. Textile Progress 37(4): 1–65. 204 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Mateja Kert Egzona Rukovci and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Aškerčeva 12 Aškerčeva 12 1000. Ljubljana. Slovenia 1000 Ljubljana Slovenia Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University Ljubljana University of Ljubljana egzonarukovci@gmail.com 386 1 200 32 34 Petra Eva Forte Tavčer mateja.kert@ntf.uni-lj.si University of Ljubljana Faculty of Natural Sciences and Engineering Department of Textiles, Graphic Arts and Design Aškerčeva 12 1000. Ljubljana, Slovenia + 386 1 200 32 93 petra.forte@ntf.uni-lj.si 205 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION RESEARCH OF THE AMOUNT OF FIBRES FRAGMENTS SHEDDING IN WASHING PROCESS OF A STANDARD 50/50% PES/ COTTON KNITTED FABRIC Agata Vinčić1, Tanja Pušić1, Ana Šaravanja1 and Lamia Farhat1 1University of Zagreb, Faculty of Textile Technology, Croatia Abstract: Since the washing process is considered one of the most influential processes in the release of fibre fragments - i.e. water pollution with microplastics - and the data situation is still imprecise and requires a lot of research, the research project InWaShed - MP (IP-2020-02-7575) was also recently carried out. In this project, the properties of PES/cotton 50/50% knitted fabrics were investigated in the washing process. The effects on the fibre fragments were investigated by simulating a washing process (60 °C, 30 min) using two different detergents as well as tap water and distilled water and the change in mass of the tested knitted fabric after 3 washing cycles in relation to the original dry mass was measured. In addition, a filtration of the residual bath was carried out - the mass of the dry residue of the bath filter was determined after three washing cycles with standard detergent and distilled water and reference baths. Keywords: washing process, detergents, microplastics pollution, PES/cotton knitted fabric, gravimetric method 1. INTRODUCTION Textiles made of synthetic polymers, of which polyester is the most common, are a significant source of micro-plastic pollution, as fragments of synthetic fibres are released due to various physical-mechanical and chemical influences during production, use and care during the life cycle and improper disposal at the end of the life cycle of textile products. According to studies (Sherrington 2016), around 35% of the total amount of microplastics re-leased into the oceans comes from the washing of textiles made from synthetic fibres. According to estimates by (UNEP 2018), the total annual amount of microplastics and macroplastics released into the environment through the washing of textiles – clothing - is 0.29 million tonnes or 3.2%. All this points to the problem of the method for determining and assessing the extent of microplastic pollution. To monitor this process and determine the quan-tities, ISO/EN/HR standards for the determination of the amount of fibre particles released during washing were adopted in 2023, further underlining the importance of this issue (EN ISO 4484-1:2023). Among other global research, the project: Assessment of microplastic shedding from polyester textiles in washing process (IP-2020-02-7575), funded by the Croatian Science Foundation for the period from 1 February 2021 to 31 January 2025, has started to investigate this topic, based on the data that one third of microplastics in wastewater comes from microplastics released from textiles during the washing process. Among the many influences on the phenomenon of fibre fragments detaching from textiles during washing are the nature and composition. Therefore, it is neces-sary to perform a variety of tests on different types of textile materials using similar methods. In this work, a test was carried out on a 50/50% PES/cotton standard knitted fabric (Farhat 2024) as a continuation of the 100% PES standard knitted fabric (Vinčić 2024) and 100% PES woven fabric (Vinčić 2022) also tested as part of the InWaShed - MP research project (IP-2020-02-7575). 2. EXPERIMENTAL In the experimental part, the simulation of the washing process (temperature 60 °C, 30 min) was carried out in the Ahiba Turbomat laboratory apparatus with 6 beakers with magnetic stirring of the bath using two different deter-gents and tap water and distilled water and the change in the mass of the tested fabric after 3 washing cycles in relation to the initial dry mass was measured. In addition, a filtration of the residual bath was carried out - the mass 206 29–30 May 2025, Ljubljana, Slovenia of the dry residue of the bath filter was determined after 3 washing cycles with standard detergent and distilled water and reference baths. The simulation of the washing process was carried out on a clean standard 50/50% cotton/PES knitted fabric with the addition of standard and Persil universal detergent in distilled and tap water and in distilled and tap water only (without detergent). 2.1 Materials In the experimental part standard polyester/cotton 50/50% weft knitted fabric was used, the characteristics of which are presented in Table 1. Table 1: Structural parameters and digital image of standard polyester/cotton 50/50% weft knitted fabric Paremeter Specification Standard fabrics supplier WFK, Germany Composition 50/50% PES/cotton Mass per unit area (g/m2) 139.5 - horizontal (Dh) 14 stiches/cm - vertical (Dv) 28 stiches/cm Dino-Lite microscopic images a) surface Magnification 50x b) cutted edge 207 29–30 May 2025, Ljubljana, Slovenia 2.2 Simulation of washing process The simulation of the washing process was carried out on the samples of PES/cotton standard weft knitted fabric in Ahiba Turbomat (Datacolor) laboratory apparatus according to the T/t diagram in Figure 1, using Persil and the standard detergent ECE A in different concentrations: – 1.5 g/L Persil - universal powder detergent (Henkel) – 1.25 g/L standard detergent ECE Formulation Non Phosphate Reference Detergent (A) without optical brighteners. The tap water used to wash the Persil detergent had a temperature of 14.50 °dH. Figure 1: Process diagram of simulated washing process The washing process was simulated in an AHIBA laboratory apparatus with magnetic stirrer of the bath according to parameters based on the HRN EN ISO 6330:2012 method. 2.3 Methods In the simulation test of the washing process of clean standard 50/50% PES/cotton knited fabric, standard deter-gent and distilled water as well as universal detergent in powder form Persil and tap water were used to prepare the bath. Samples 1 and 2 of all tested series were processed without the addition of detergents - i.e. only in tap water or distilled water - and samples 3, 4, 5 and 6 in the bath with the addition of detergents in the water. The simulation of the washing process was carried out at a temperature of 60 °C, gradually increasing the tempe-rature for 10 minutes and processing (washing) at 60 °C for 30 minutes with magnetic circulation of the bath. After simulating the washing process, the samples were rinsed and dried until they were completely dry. Their mass was then determined and the value of the mass change in relation to the mass of the samples before washing was calculated. In addition to measuring the mass change, the bath samples were filtered with standard detergent and distilled water after the washing process. The filtration of the collected residual baths and the mass of the filtered dry mass was determined on FilterBio® polyestersulphone filters - 47 mm diameter and 0.22 μm pore size. 3 x 200 ml were separated from each bath sample, i.e. three parallel filtrations were carried out, from which the average values were determined. 3. RESULTS WITH DISCUSSION The results of the change in mass after the 3rd cycle of the washing process are shown in Figure 2. Based on the variations obtained, the results clearly confirm the complexity and sensitivity of these tests, and it was confirmed that the results are significantly influenced by the type of detergent in combination with the water used. Figure 2 shows the cumulative values of the changes in the mass of the samples, expressed as a percentage in relation to the initial mass (dry mass of the samples before washing). The results obtained are surprising: after the first cycle, a loss of mass was observed for some samples and an increase in mass for others, but after the third washing cycle, these increase values are very large and almost the same for all comparative samples (Figure 3a, samples 3P - 6P). The change in mass of the tested samples washed with Persil after the 3rd wash cycle has a positive 208 3. RESULTS WITH DISCUSSION The results of the change in mass after the 3rd cycle of the washing process are shown in Figure 2. Based on the variations obtained, the results clearly confirm the complexity and sensitivity of these tests, and it was 29–30 May 2025, Ljubljana, Slovenia confirmed that the results are significantly influenced by the type of detergent in combination with the water used. Figure 2 shows the cumulative values of the changes in the mass of the samples, expressed as a percentage in relation to the initial mass (dry mass of the samples before washing). The results obtained are surprising: after the first cycle, a loss of mass was observed for some samples and an increase in mass for sign, i.e. there was an increase in mass, on average +1.66%. Although the accuracy of the results obtained may others, but after the third washing cycle, these increase values are very large and almost the same for all be questioned, the increase in the comparative samples is relatively uniform, which could indicate the phenome comparative samples (Figure 3a, samples 3P - 6P). The change in mass of the tested samples washed with - tests should be carried out with the same samples and under the same washing process conditions. Although the accuracy of the results obtained may be questioned, the increase in the comparative samples is relatively uniform, which could indicate the phenomenon of precipitation of the detergent and/or interaction non of precipitation of the detergent and/or interaction with the tap water or a systematic error. In any case, further Persil after the 3rd wash cycle has a positive sign, i.e. there was an increase in mass, on average +1.66%. A lower average increase in mass was also observed with standard detergent (+0.13%) (Figure 3b, samples 3S with the tap water or a systematic error. In any case, further tests should be carried out with the same samples - 6S). The results of the mass of the dry residue of the bath filter after three washing cycles carried out on the and under the same washing process conditions. residual bath from the wash with standard detergent and distilled water are shown in Figure 3. A lower average increase in mass was also observed with standard detergent (+0.13%) (Figure 3b, samples 3S - 6S). The results of the mass of the dry residue of the bath filter after three washing cycles carried out on the residual bath from the wash with standard detergent and distilled water are shown in Figure 3. Change in mass % Change in mass % 2,50% 2,50% 2,00% 1,50% 1,50% 1,00% 0,50% 0,50% 0,00% -0,50% 1V 2V 3P 4P 5P 6P -0,50% 1DV 2DV 3S 4S 5S 6S a) b) Figure 2: PES/cotton knitted fabic change in mass after 3rd washing cycles: Figure 2: PES/cotton knitted fabic change in mass after 3rd washing cycles: a) samples 1V and 2V only in tap water, samples 3P, 4P, 5P and 6P in Persil + tap water 29–30 May 2025, Ljubljana, Slovenia a) b) samples 1DV and 2DV only in distilled water, samples 3S, 4S, 5S and 6 in Standard detergent ECE + samples 1V and 2V only in tap water, samples 3P, 4P, 5P and 6P in Persil + tap water b) samples 1DV and 2DV only in distilled water, samples 3S, 4S, 5S and 6 in Standard detergent ECE + distilled water distilled water Mass difference (g) 3 0,06 g) 0,04 m ( 0,02 Δ 0 1 2 3 4 Samples Figure 3: Figure 3: Mass difference of the samples of the dry residue of the bath filter: 1 - standard detergent and Mass difference of the samples of the dry residue of the bath filter: 1 - standard detergent and distilled water distilled water after three washing cycles without knit samples, 2 - referent bath of standard detergent and after three washing cycles without knit samples, 2 - referent bath of standard detergent and distilled water (without washing distilled water (without washing process), 3 - bath after three washing cycles of the knit samples with distilled process), 3 - bath after three washing cycles of the knit samples with distilled water, 4 - bath after three washing cycles of the water, 4 - bath after three washing cycles of the knit samples with standard detergent and distilled water knit samples with standard detergent and distilled water sample 2 (standard detergent and distilled water – unused bath), followed by the same bath (sample 1) processed bath after washing the knitted fabric in distilled water only (sample 3) and the smallest mass difference for under similar conditions (at 60 °C) but without the knitted fabric sample, followed by the remaining bath after sample 4 – a bath with standard detergent and distilled water after washing the knitted fabric. However, these washing the knitted fabric in distilled water only (sample 3) and the smallest mass difference for sample 4 – a bath results could be related to the deposition of detergent on the knitted fabric samples (which can be explained with standard detergent and distilled water after washing the knitted fabric. However, these results could be relat-by the average increase in their mass after washing). The cotton content in the blend most likely affects the ed to the deposition of detergent on the knitted fabric samples (which can be explained by the average increase The results from Figure 3 are interesting and surprising. The largest mass difference was found for reference sample 2 (standard detergent and distilled water – unused bath), followed by the same bath (sample 1) processed under similar conditions (at 60 °C) but without the knitted fabric sample, followed by the remaining The results from Figure 3 are interesting and surprising. The largest mass difference was found for reference greater deposition of detergent on the 50/50% PES/cotton knitted fabric, as the cotton fibres have a greater in their mass after washing). The cotton content in the blend most likely affects the greater deposition of detergent possibility of forming different bonds and have a higher substantivity and absorptivity. on the 50/50% PES/cotton knitted fabric, as the cotton fibres have a greater possibility of forming different bonds and have a higher substantivity and absorptivity. 4. CONCLUSIONS The results of this research provide a better insight into the influence of raw material composition on the release microplastic pollution and help in the development of new methods and procedures to determine and reduce 209 of microparticles, i.e. fibre fragments, which will contribute to a better understanding of their contribution to the emission of microplastics from textile materials. They will also contribute to expanding the database of the InWaShed - MP research project (IP-2020-02-5757), which is funded by the Croatian Science Foundation (HrZZ). 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS The results of this research provide a better insight into the influence of raw material composition on the relea-se of microparticles, i.e. fibre fragments, which will contribute to a better understanding of their contribution to microplastic pollution and help in the development of new methods and procedures to determine and reduce the emission of microplastics from textile materials. They will also contribute to expanding the database of the InWaS-hed - MP research project (IP-2020-02-5757), which is funded by the Croatian Science Foundation (HrZZ). These results, which showed an increase in the mass of the tested samples after three washing cycles, and a comparison with similar tests carried out on 100% PES knitted fabic, indicate the influence of cotton in a blend with polyester. As cotton interacts more readily with the bath due to its absortivity and substantivity during washing (of different compositions), it may indirectly influence the reduced release of PES fibre fragments into the bath, i.e. the wastewater. Although further testing is needed, this could be one of the solutions to reduce the problem, i.e. the amount of fibre microparticles released during washing, i.e. microplastics. 5. ACKNOWLEDGEMENTS This research was funded by Croatian Science Foundation, grant number HRZZ-IP-2020-02-7575. 6. REFERENCES European Standard EN ISO 4484-1:2023, February 2023. Farhat, L (2024): Comparison of the release of fiber microparticles in the washing of different standard polyester knits. Final Bc Thesis, University of Zagreb Faculty of Textile Technology. Sherrington, C. (2016): Plastics in the marine environment, Eunomia, Bristol, UK, http://eunomia.eco/reports/plastics-in-the-marine-environment (Accessed: 25 March 2021). UNEP (2018): Mapping of global plastics value chain and plastics losses to the environment: with a particular focus on marine environment, United Nations Environment Programme, https://www.unep.org/pt-br/node/27212 (Accessed: 6 May 2021). Vinčić, A., Pušić, T. et al. (2022) ‘Release of PES fibre particles during washing - estimation by reducing the fabric mass and dry mass of the residual bath’, in Book of Proceedings of the 10th International Textile, Clothing & Design Conference, ed. By Zvonko Dragčević, Faculty of Textile Technology, University of Zagreb, pp.160-166. Vinčić, A., Pušić, T. et al. (2024) ‘Determination of the amount of released fiber microparticles in the washing of standard polyester knitted fabric’, in Book of Proceedings of the 11th International Textile, Clothing & Design Conference, ed. by Anica Hursa Šajatović, Ivana Špelić, Faculty of Textile Technology, University of Zagreb, pp. 143-148. 210 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Faculty of Textile Technology Department of Textile Chemistry Study unit Varaždin and Ecology Hallerova aleja 6a Prilaz baruna Filipovića 28a HR-42 000 Varaždin, Croatia HR-10000 Zagreb, Croatia University of Zagreb University of Zagreb Faculty of Textile Technology Agata Vinčić, senior lecturer Prof. Tanja Pušić, Ph.D. +(385) (1) 4877 353 +(385) (42) 330 676 tanja.pusic@ttf.unizg.hr agata.vincic@ttf.unizg.hr Ana Šaravanja, Ph.D. student University of Zagreb Faculty of Textile Technology Department of Textile Chemistry and Ecology Prilaz baruna Filipovića 28a HR-10000 Zagreb, Croatia +(385) (1) 4877 353 ana.saravanja@ttf.unizg.hr Lamia Farhat, bacc. ing. techn. text. University of Zagreb Faculty of Textile Technology Study unit Varaždin Hallerova aleja 6a HR-42 000 Varaždin, Croatia +(385) (42) 330 676, lamia.farhat@ttf.unizg.hr 211 INNOVATIVE TEXTILE PROCESSING, DIGITALISATION AND INDUSTRY 5.0 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION COMPUTERIZED CREATION OF NOVELTY WEAVES Dušan Peterc1 1Arahne, d.o.o., Slovenia Abstract: Traditional weaving textbooks usually present a classification of basic weaves, combined with methods for creation of new weaves. We present new methods of algorithmic creation of weaves, which are nowadays possible thanks to the use of CAD software. We explain these methods as implemented in ArahPaint jacquard drawing program and ArahWeave jacquard weaving CAD. The created weaves vary in use by satisfying specific technical properties, for example crepe weave with desired float length. We also want the weaves to repeat nicely, and be visually regular, free of unwanted stripes. Keywords: weaving jacquard CAD parametric generation 1. INTRODUCTION Textile schoolbooks have a long tradition and they all present their own weave classification, accompanied by some step by step instructions for creation of new weaves, by combining the existing ones (Brickett 1934, Giudici 1943, Holyoke 2013, Kienbaum 2016, Rodón i Amigó 1930). This can be done simply by using a basic weave block and rotating it by 90/180/270 degrees, by placing rotated blocks arranged in a regular pattern, by super-imposing weaves, by interlacing them, by adding points to existing weave using some rules, etc. In a modern terminology, we would call these instructions algorithms for weave constructions. We will concentrate on single layer weaves, as multiple layer weaves are usually created on the fly by the design-er based on a specific construction need. Most textile CAD software offers tools to automate these processes. But some push the boundaries even further, and provide additional tools with more complex algorithms, which the old masters could not envision. We will explain some functions, which have been implemented in software packages ArahPaint (Gregorčič 2025) and in ArahWeave (Gregorčič 2025). Usually we construct a weave with the aim to achieve certain surface effect, while respecting some technical production limitations, like maximum length of floats, weave repeat size (for divisibility), visual appeal (must be balanced without unwanted lines in any direction). One classical example of such a weave construction is crepe weave. It is quite difficult to do for shaft weaving, so even today in the industry they always use the same 3-4 good crepe weaves. For jacquard, we are free to make much larger weaves, so we present an algorithm for creation of crepe weave of any repeat size, intensity level (warp to weft effect) or length of maximum float. 2. MAKING NOVELTY WEAVES BY CAD 1.1 Crepe weaves by random weave mirroring One approach we use in ArahPaint is to chose a suitable starting motif, then we call the function to create random mirroring layout of the motif, and finally we create the new weave. The advantage of this approach is that we can easily make very large weaves, which match the number of hooks on our jacquard. The bigger the weave, the more regular it will look. Since our base weave was carefully chosen, we do not have any long floats. 213 29–30 May 2025, Ljubljana, Slovenia Figure 1: Base weave for expansion by random mirroring Figure 2: Setting the layout for expansion by random mirroring 214 29–30 May 2025, Ljubljana, Slovenia Figure 3: The resulting crepe weave of size 240x240 1.2 Simulating flame yarns by randomly inverting weave areas Weavers always try to achieve maximum effect using minimal tools. For example, flame yarn is more expensive than regular yarn, and we try to get the effect of flame yarn look just by using special weave. We start with plain weave, and then we use the software to randomly invert sections of single warp and single weft. The starting position is random, and length is also random, but parametric. In areas where the weave was inverted, the yarns weave in the same way, so they are grouped together. As a result, you will get a view of irregular yarn in the fabric. Since the algorithm to place the invert operation works in repeat, there will be no visible defect on the border. Once again, we can easily use this approach to make weaves of any size, so we are sure to use the whole capacity of the jacquard at hand, and we made a design which is hard to copy. Figure 4: The resulting crepe weave of size 240x240 215 29–30 May 2025, Ljubljana, Slovenia 1.3 Creating irregular crepe by randomly inverting weave areas In upholstery fabrics, we often wish to create an irregular texture, and generally it is difficult to create a weave or pattern that is free of visual stripes across the repeat. We want the repeat to be invisible to the viewer, but also to have he right amount of irregularity, so that the design is not dull. Once again, we are using the random invert function on plain weave. This time we create 10000 inverted filled rectangles, randomly placed, and with random size between 10 and 200 weave points. Since some junction areas are unpredictable because of the overlapping random operations, we could have areas of long floats. So we also call the function to correct the long float with maximum permitted float of 6 points. Figure 5: Irregular crepe for upholstery 1.4 Creating crepe weave by random using variable intensity Another way of creating crepe weaves is to simply define the desired weave size, for example 1200x1200, and warp/weft intensity ratio. In ArahWeave, we define the intensity between 0 and 255, so for mid level crepe, we should use the intensity of 128. Program simply creates a random mix of black and white points with given intensity. In order to use it as a weave, we also define the maximum number of allowed long floats. The value depends on the intended fabric usage and weaving density, in this case we use 3. 216 29–30 May 2025, Ljubljana, Slovenia Figure 6: Random crepe weave 1200x1200 with maximum float of 3 Since we have full freedom of setting the intensity of the warp to weft effect, we can push it a little further and directly create gradient effect with the crepe weave, by setting the minimum and maximum effects, we can even make it bidirectional or use an angle. This kind of weave are very appreciated by designers of curtains or shawls, since they can make a weave with the size that matches their design requirements. Figure 7: Random shaded crepe weave 600x600 with maximum float of 4 217 29–30 May 2025, Ljubljana, Slovenia 1.5 Creating weaves by motif rotation and zoom The discovery of this method was a result of our research motif rotation in repeat. Very often, we have a base motif which is in block repeat, and we wish to rotate it by a certain angle, while keeping the repeat property and not deforming the design. Usually we do it by 45 degrees in order to get diamond repeat. Some famous brands like Burberry use a complex interlaced rotated design as a way of protection of their brand and intellectual property. Intuitively we would think that we can rotate the existing repeating image by any angle, but in reality it is only pos-sible for certain well defined angles for square designs. We have programmed this capability in ArahWeave. But we went even a step further, and allowed motif rotation and resize within the ArahPaint drawing program. Using even extremely simple core pattern like plain weave (repeat 2x2), we get a whole group of patterns defined by their angle and rotation. The operation is extremely sensitive, so we can use the decimal points of the parameters to gradually change the pattern appearance. Since the core pattern is so small, we do not get long floats in the resulting image. Surprisingly enough, many of the resulting designs have satin counterpoints placed correctly, as if they were drawn by an actual designer. We said before that arbitrary motif rotation in repeat is not possible, so how can can we use the non-repeating result in weaving? We can repeat it several times and use ArahPaint’s function for automatic repeat detection. In many cases the repeat will not be perfect, but it will be close enough to be visually convincing and usable. Figure 8: Plain weave rotated by angle 152º and zoomed at 149% generates this pattern How can simple rotation and zoom create such a rich set of patterns? We are familiar with aliasing problem, where we have to approximate a line of a circle with a limited resolution, and we get jaggies when the line skips the point edge. This pixelization is normally a defect which we can not avoid. But in this case, we use the distribution of these digital errors as design tool, and it creates whole group of pleasing patterns. ArahWeave is free for download from Arahne’s web site, and anyone can play with the angle and zoom to get in-teresting weaves. Since the space is limited, we can’t show more of them, here are some pairs of angle and zoom to try with plain weave: (52º, 149%) (20º, 110%) (19º, 107%) (23º, 0.3%) (29.8º, 124%). 218 29–30 May 2025, Ljubljana, Slovenia 2. CONCLUSION Graphics designers have fully embraced digital design. They use vector tools, filters, some even write scripts or shaders to get the effect that they want. Many woven designers still work in traditional way, despite working with computer on CAD. Because CAD only mirrors and automates the traditional manual way of image coloring and color to weave substitution. Woven designers can raise their art to the next level, if they start embracing digital generative methods of design and weave creation. Appropriate software can help a lot, since it can take care of long floats and repeat correctness already at level of creation, not as a post-processing step. 3. REFERENCES: Brickett, C.J. 1934. Textile Designing. Scranton, PA.: International Textbook Company Giudici, O. 1943. Tessuti di Lana e di Cotone: Analisi e Fabbricazione. Milano: Ulrico Hoepli Holyoke J. 2013. Digital Jacquard Design. London, New Delhi, New York, Sydney: Bloomsbury Kienbaum M. B. 2016. Binding Technology of Fabrics: Book 1: Single surface fabrics. Goldkronach: CH-Consulting Rodón i Amigó P. 1930. Ligamentos Crepes. Badalona: Cataluña Textil Gregorčič, A., Peterc, D. 2025. ArahWeave User’s Manual. URL: https://www.arahne.eu/pdf/aweave-EN.pdf (last accessed on 1.03.2025). Gregorčič, A. 2025. ArahPaint User’s Manual. URL: https://www.arahne.eu/pdf/apaint6-EN.pdf (last accessed on 1.03.2025). ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Dušan Peterc Arahne, d.o.o. Novinarska 3 1000 Ljubljana, Slovenia +386-1-439-5280 dusan.peterc@gmail.com 219 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION CREATING A DATABASE FOR OPERATION LIST IN GARMENT PRODUCTION PROCESS Selma Imamagić1, Anica Hursa Šajatović1 and Bosiljka Šaravanja1 1University of Zagreb, Faculty of Textile Technology, Croatia Abstract: Digital transformation is a strategy that incorporates digital technologies into all areas of an organisation. To achieve this, an organisation must go through digitisation and digitalisation processes. Digitisation involves the conversion of information from analogue to digital form, while digitalisation uses digital solutions to make business processes more automated. This paper provides an insight into the digitalisation process in garment production by creating a digital operation list. The list of technological operations of the technological process of sewing a wom-an medical coat was used as an example. A database for storing information and an application for entering and linking data were also developed. As a result, digital operation list for sewing woman medical coat was gained. In this form, it can become available to all users of the application anytime and anywhere (provided they have an Internet connection) and is unlikely to be lost or damaged. Keywords: operation list, digitalisation, database, application, garment industry. 1. INTRODUCTION Today’s rapidly changing market needs involving quality products with a variety of categories, materials and de-signs, pose a major challenge to manufacturing systems. To thrive in such a market, manufacturers must adapt their production processes (Borangiu et al. 2020). As mentioned in Borangiu et al. (2020), digital transformation in industry can improve the sustainability and maintainability of manufacturing processes, products, systems and logistics through resource instrumentation and virtualisation as well as data analytics, machine learning and cloud services. According to Trzaska et al. (2021), digital transformation is a process of devising new business applications that integrate all digitised data and digitised applications. It involves the integration of digital technologies into all areas of an organisation creating a new digital business model (TecnoSolutiones). The basic step in the digital transfor-mation process is digitisation (Fig. 1), a process of converting data from analogue to digital format (Savić 2019). The second step in this transformation model is digitalisation, which is defined by Gartner Glossary as the use of digital technologies to change the business model and provide new revenue and value-producing opportunities. 220 that integrate all digitised data and digitised applications. It involves the integration of digital technologies into digital transformation process is digitisation (Fig. 1), a process of converting data from analogue to digital 29–30 May 2025, Ljubljana, Slovenia format (Savić 2019). The second step in this transformation mode all areas of an organisation creating a new digital business model (TecnoSolutiones). The basic step in the l is digitalisation, which is defined by Gartner Glossary as the use of digital technologies to change the business model and provide new revenue and value-producing opportunities. 29–30 May 2025, Ljubljana, Slovenia Figure 1: The digital transformation pyramid (O'Leary 2022) Figure 1: The digital transformation pyramid (O‘Leary 2022) The problem of integrating digital transformation can be seen in the case of small and medium-sized enterprises The problem of integrating digital transformation can be seen in the case of small and medium-sized 1 (SMEs) (Telukdarie et al. 2023). In addition, enterprises (SMEs) (Telukdarie et al. 2023). In addition, Moeuf et al. (2018) highlighted that these companies use the concept Moeuf et al. (2018) highlighted that these companies of Industry 4.0, i.e. intelligent digital technologies, mainly for monitoring industrial processes and that there is still use the concept of Industry 4.0, i.e. intelligent digital technologies, mainly for monitoring industrial processes a lack of real applications in the field of production planning. With this in mind, this paper gives an example of the and that there is still a lack of real applications in the field of production planning. With this in mind, this paper creation of a digital operation list for production planning in the garment industry. The importance of digitalisation gives an example of the creation of a digital operation list for production planning in the garment industry. The of this area and the resulting benefits can be found in importance of digitalisation of this area and the resulting benefits can be found in Alexopoulos et al. (2022) and Jeske et al. Alexopoulos et al. (2021). (2022) and Jeske et al. (2021). 2. EXPERIMENTAL PART 2. EXPERIMENTAL PART 2.1 Input data The aim of this work was to create a digital operation list for a garment. The operation list in garment industry 2.1 Input data lists the technological operations required to produce a garment and the order in which they are carried out. The following information must be provided for each technological operation: the number of the operation in the per The aim of this work was to create a digital operation list for a garment. The operation list in garment industry -formance order, its name, the resources required for its performance, its performance complexity and duration. lists the technological operations required to produce a garment and the order in which they are carried out. As an example of the operation list, the list of technological operations for the technological process of sewing the The following information must be provided for each technological operation: the number of the operation in women‘s medical coat “Vera“ was taken from Šaravanja et al. (2024), Fig. 2. the performance order, its name, the resources required for its performance, its performance complexity and duration. As an example of the operation list, the list of technological operations for the technological process of sewing the women's medical coat “Vera“ was taken from Šaravanja et al. (2024), Fig. 2. a. b. Figure 2: Women‘s medical coat “Vera“: a- technical drawing, b- operation list (Šaravanja et al. 2024) Three different machines, i.e. resources were used to sew the medical coat shown above: single needle lockstitch machine (SNLS), semi-Figure 2: Women's medical coat “Vera“: a- technical drawing, b- operation list (Šaravanja et al. 2024) th automatic buttonhole sewing machine (BH Semi-Auto) and special sewing machine (SSM). Manual work (MNL) seen in 15 technological operation was not considered as a separate resource in this paper. In addition, most of technological operation Three different machines, i.e. resources were used to sew the medical coat shown above: single needle of sewing the “Vera” medical coat are the technological operations of medium performance difficulty, with the exception of the lockstitch machine (SNLS), semi-automatic buttonhole sewing machine (BH Semi-Auto) and special sewing 4 th one, which requires skilled worker to perform it. machine (SSM). Manual work (MNL) seen in 15 th technological operation was not considered as a separate resource in this paper. In addition, most of technological operation of sewing the "Vera" medical coat are the technological operations of medium performance difficulty, with the exception of the 4th one, which requires skilled worker to perform it. 2.2 Methods 221 In order to create a digital operation list, it was first necessary to create a database. For this purpose, SQL 29–30 May 2025, Ljubljana, Slovenia 2.2 Methods In order to create a digital operation list, it was first necessary to create a database. For this purpose, SQL Server was used. The created database with the name OperationList, was filled with the following tables: Resources, Products, Complexity, Units, Operations, Technology and UsedResources. These tables are essential for storing data: in this case, information about the technological process of sewing women’s medical coat from the corre- sponding operation list (Fig. 2-b). 29–30 May 2025, Ljubljana, Slovenia The next step was to build a project, i.e. an application using the Python programming language, also called Operation List, and connect it to the database that had been created. As a result, it was enabled to store data for the technological process of sewing the “Vera” women’s medical coat using the Operation List application in the above-mentioned tables of the OperationList database. for the technological process of sewing the "Vera" women's medical coat using the Operation List application in the above-mentioned tables of the OperationList database. Figure 3 shows the resource entry field. Here the user of the Operation List application can enter the desired data about resources by selecting the Resource button. These are: Figure 3 shows the resource entry field. Here the user of the Operation List application can enter the desired data about resources by selecting the • resource ID: marker of the resource that is displayed in the digital operation list Resource button. These are: • resource ID: marker of the resource that is displayed in the digital operation list • description: full name of the resource • description: full name of the resource • operating time: time per day in which a resource is accessible (e.g. one shift: 450 minutes) • operating time: time per day in which a resource is accessible (e.g. one shift: 450 minutes) • row in chart: the position of the resource when creating a diagram (e.g. Gantt chart). • row in chart: the position of the resource when creating a diagram (e.g. Gantt chart). For this paper, the information of three machines required for sewing the medical coat (SNLS, BH Semi_Auto For this paper, the information of three machines required for sewing the medical coat (SNLS, BH Semi_Auto and and SSM) were entered. Products, units and complexity data were also entered in the same way (buttons of SSM) were entered. Products, units and complexity data were also entered in the same way (buttons of the same the same name in the menu bar). name in the menu bar). Figure 3: Resource entry filed in the Operation List application Figure 3: Resource entry filed in the Operation List application technological operations as well as the type of technology and the resources used to perfom them are defined The Operation List button in the menu bar is used to define elements of a new digital operation list. The technolo-The Operation List button in the menu bar is used to define elements of a new digital operation list. The here. gical operations as well as the type of technology and the resources used to perfom them are defined here. Figure 4 shows defining first of 19 technological operations required to produce a “Vera“ coat. By entering Figure 4 shows defining first of 19 technological operations required to produce a “Vera“ coat. By entering them, them, this information has been entered directly into the digital operation list that has just been created. this information has been entered directly into the digital operation list that has just been created. Therefore, for Therefore, for each operation it must be defined: each operation it must be defined: • variant name: name used for possible changes in the production of the same product (e.g. when • variant name: name used for possible changes in the production of the same product (e.g. when changing changing resources, technology, requeired time, sequence of performing etc.) resources, technology, requeired time, sequence of performing etc.) • product ID: Identification of the product in the database • product ID: Identification of the product in the database • technology number: number of the type of technology in the database • technology number: number of the type of technology in the database • operation number: represents the number of the technological operation in the sequence of their • operation number: represents the number of the technological operation in the sequence of their perfor-performing (e.g. the first technological operation is defined with the number 10) ming (e.g. the first technological operation is defined with the number 10) • predecessor operation: number of the technological operation that precedes a defined operation (e.g. • predecessor operation: number of the technological operation that precedes a defined operation (e.g. the the first technological operation has no predecessor, so a zero must be entered in this field) first technological operation has no predecessor, so a zero must be entered in this field) • complexity: Identification of the performance difficulty (e.g. II: medium performance difficulty). • complexity: Identification of the performance difficulty (e.g. II: medium performance difficulty). 222 • product ID: Identification of the product in the database • technology number: number of the type of technology in the database • operation number: represents the number of the technological operation in the sequence of their 29–30 May 2025, Ljubljana, Slovenia performing (e.g. the first technological operation is defined with the number 10) • predecessor operation: number of the technological operation that precedes a defined operation (e.g. the first technological operation has no predecessor, so a zero must be entered in this field) • complexity: Identification of the performance difficulty (e.g. II: medium performance difficulty). 29–30 May 2025, Ljubljana, Slovenia Figure 4: Defining first operation of sewing medical coat “Vera“ in the Operation List application 29–30 May 2025, Ljubljana, Slovenia Figure 4: Defining first operation of sewing medical coat “Vera“ in the Operation List application As a result, a draft version of the digital operation list is created, Fig. 5., where each technological operation can As a result, a draft version of the digital operation list is created, Fig. 5., where each technological operation be edited, deleted or added if necessary. By clicking the Resource button on the left-hand side of the draft version, 3 can be edited, deleted or added if necessary. By clicking the Resource button on the left-hand side of the draft each technological operation in this operation list is linked to the associated machine and duration, Fig. 6. version, each technological operation in this operation list is linked to the associated machine and duration, As a result, a draft version of the digital operation list is created, Fig. 5., where each technological operation Fig. 6. can be edited, deleted or added if necessary. By clicking the Resource button on the left-hand side of the draft version, each technological operation in this operation list is linked to the associated machine and duration, Fig. 6. Figure 5: Figure 5: Draft version of digital operation list Draft version of digital operation list Figure 5: Draft version of digital operation list Figure 6: Linking resources and technological operations of tehnological process of sewing “Vera“ medical coat Figure 6: Linking resources and technological operations of tehnological process of sewing “Vera“ Figure 6: Linking resources and technological operations of tehnological process of sewing “Vera“ medical coat medical coat 3. RESULTS WITH DISCUSSION The result of this paper is a digital operation list (Fig. 7) of a product, in this case the technological process for 3. RESULTS WITH DISCUSSION sewing the "Vera" medical coat, which is available to all users, i.e. the employees of a production company, 223 The result of this paper is a digital operation list (Fig. 7) of a product, in this case the technological process for anytime and anywhere (provided they have an Internet connection). Employees can easily store the required sewing the "Vera" medical coat, which is available to all users, i.e. the employees of a production company, data on resources, products and technologies in the databases with the help of the developed application and later link them in the operation list. Technologists can create new operation lists or use information from existing 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS WITH DISCUSSION The result of this paper is a digital operation list (Fig. 7) of a product, in this case the technological process for sewing the “Vera” medical coat, which is available to all users, i.e. the employees of a production company, any-time and anywhere (provided they have an Internet connection). Employees can easily store the required data on resources, products and technologies in the databases with the help of the developed application and later link 29–30 May 2025, Ljubljana, Slovenia them in the operation list. Technologists can create new operation lists or use information from existing ones. In addition, digital operation lists can be stored securely and, unlike physical documents, are rarely lost or damaged. Figure 7: Digital operation list of the technological process of sewing medical coat “Vera“ Figure 7: Digital operation list of the technological process of sewing medical coat “Vera“ Digital operation list created in this paper represents one of the steps in the digital transformation of the production process, respectively planning in the garment industry. Considering that in the production planning process exists a lack of application of concepts of Industry 4.0 in SMEs (Moeuf et al. 2018) and that these Digital operation list created in this paper represents one of the steps in the digital transformation of the production companies make up 99% of all companies in the EU (European Commission), there is certainly process, respectively planning in the garment industry. Considering that in the production planning process exists a potential for digitalisation in this field. This includes creating more technical documents using digital technologies and a lack of application of concepts of Industry 4.0 in SMEs (Moeuf et al. 2018) and that these companies make up linking them together to digitalise all processes in manufacturing systems. As a result, manufacturing 99% of all companies in the EU (European Commission), there is certainly a potential for digitalisation in this field. companies will improve their efficiency, resource utilisation and product quality, reduce operating costs and be This includes creating more technical documents using digital technologies and linking them together to digitalise able to adapt quickly to changes in customer demands and the market (Duraivelu 2022). all processes in manufacturing systems. As a result, manufacturing companies will improve their efficiency, re- source utilisation and product quality, reduce operating costs and be able to adapt quickly to changes in customer Nevertheless, the aim of this paper was to give an insight into the digital documents’ creation (database and demands and the market (Duraivelu 2022). application). As regards, there certainly exists the possibility of improving and upgrading created digital operation list or adding other elements, primarily depending on the type of manufacturing. Nevertheless, the aim of this paper was to give an insight into the digital documents’ creation (database and ap- plication). As regards, there certainly exists the possibility of improving and upgrading created digital operation list or adding other elements, primarily depending on the type of manufacturing. 4. CONCLUSIONS Digital transformation means integrating digital technologies in all areas of an organisation. It makes it possible to respond to rapidly changing customer behaviour, i.e. expectations and needs, and to remain competitive on the market. The literature review revealed that the integration of this concept is lacking in small and medium-224 sized enterprises (SMEs), which represent the majority of companies in the EU today. In this sense, this paper shows an example of the creation of a digital operation list – one of the basic technical 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS Digital transformation means integrating digital technologies in all areas of an organisation. It makes it possible to respond to rapidly changing customer behaviour, i.e. expectations and needs, and to remain competitive on the market. The literature review revealed that the integration of this concept is lacking in small and medium-sized enterprises (SMEs), which represent the majority of companies in the EU today. In this sense, this paper shows an example of the creation of a digital operation list – one of the basic technical documents in production planning in the garment industry. The creation of digital operation list can provide a basis for further researches and improvements of given document as well as and the continuation of digital transforma-tion of the manufacturing process. 5. REFERENCES Alexopoulos, K., Nikolakis, N. and Xanthakis, E. (2022) ’Digital Transformation of Production Planning and Control in Manufacturing SMEs-The Mold Shop Case’, Applied Sciences, 12, pp. 1-14 Borangiu, T., Morariu, O., Răileanu, S., Trentesaux, T., Leitão, P & Barata, J. (2020) ’Digital transformation of manufacturing. Industry of the Future with Cyber-Physical Production Systems’, Romanian Journal of Information Science and Technology, 23 (1), pp. 3-37 Duraivelu, K. (2022) ‘Digital transformation in manufacturing industry – A comprehensive insight’, Materials Today: Proceedings, 68 (6), pp. 1825-1829 European Commission. SME definition. Available at: https://single-market-economy.ec.europa.eu/smes/sme-fundamentals/sme-definition_ en (Accessed: 20. 10. 2024) Gartner Glossary. Digitalization. Available at: https://www.gartner.com/en/information-technology/glossary/digitalization (Accessed: 18. 10. 2024) Jeske, T., Würfels, M. And Lennings, F. (2021) ‘Development of Digitalization in Production Industry – Impact on Productivity, Management and Human Work’, Procedia Computer Science, 180, pp. 371-380 Moeuf, A., Pellerin, R., Lamouri, S., Tamayo, S. and Barbaray, R. (2018) ‘The industrial management of SMEs in the era of Industry 4.0’, International Journal of Production Research, 56 (3), pp. 1118-1136 O’Leary, D. E. (2022) ‘Digitization, Digitalization and Digital Transformation in Accounting, Electronic Commerce and Supply Chains’, USC Marshall School of Business Research Paper Series, pp. 1-18 Savić, D. (2019) ‘From Digitization, Through Digitalization, to Digital Transformation’, Online Searcher, 43 (1), pp. 36-39 Tecno-Soluciones. Digitalization and Digital Transformation What are the differences between them?. Available at: https://tecnosoluciones. com/digitalization-and-digital-transformation-what-are-the-differences-between-them/?lang=en&pdf=51693 (Accessed: 17. 10. 2024) Telukdarie, A., Dube, T., Matjuta, P. and Philbin, S. (2023) ’The opportunities and challenges of digitalization for SME’s’, Procedia Computer Science, 217, pp. 689-698 Trzaska, R., Sulich, A., Organa, M., Niemczyk, J. and Jasiński, B. (2021) ‘Digitalization Business Strategies in Energy Sector: Solving Problems with Uncertainty under Industry 4.0 Conditions’, Energies, 14, pp. 1-21 Šaravanja, B., Imamagić, S., Marković, P. and Hursa Šajatović, A. (2024) “Setting standard time for the technological process of sewing woman’s medical coat “Vera””. In Book of Proceedings of the 11th International Textile, Clothing & Design Conference, edited by Hursa Šajatović, A., Špelić, I. et al., 169-174, Zagreb: University of Zagreb, Faculty of Textile Technology ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Faculty of Textile Technology Faculty of Textile Technology Department of Clothing Technology Department of Clothing Technology Department of Clothing Technology Prilaz baruna Filipovića 28a Prilaz baruna Filipovića 28a Prilaz baruna Filipovića 28a 10 000 Zagreb, Croatia University of Zagreb University of Zagreb University of Zagreb Faculty of Textile Technology Selma Imamagić Prof. Anica Hursa Šajatović, Ph.D. Assist. prof. Bosiljka Šaravanja, Ph.D. 10 000 Zagreb, Croatia +(385) (1) 3712 551, 10 000 Zagreb, Croatia +(385) (1) 3712 544 anica.hursa@ttf.unizg.hr bosiljka.saravanja@ttf.unizg.hr selma.imamagic@ttf.unizg.hr 225 TEXTILE BASED COMPOSITES AND TECHNICAL TEXTILES 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION THE INFLUENCE OF THE LAYER STRUCTURE ON THE DURABILITY OF TEXTILE LAMINATES Dunja Šajn Gorjanc1 and Barbara Golja1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The research focuses on two-layer laminates, which are used in the automotive industry for the uphol-stery of car seats. The investigated laminates are produced in a dry lamination process on a static laminator at a constant pressure of 3 bars. The front side of the laminate consists of a 3D knitted fabric and a multilayer nonwo-ven fabric, while the back side is made of nonwoven or woven fabric. In this research the influence of the structure of the laminate top side on the durability of the laminate is being investigated in more detail. The results showed that the integration of a three-dimensional knitted fabric has a significant effect on increasing the strength under compressive load with a ball. On the other hand, the three-dimensional knitted fabric in the laminate reduces the delamination force of the laminate. Keywords: laminate, 3D knitted fabric, multilayer nonwoven, dry lamination 1. INTRODUCTION The interior of a vehicle can consist of textile laminates. Depending on the number of layers and the technological processes of lamination, textile laminates are divided into several groups (Joshi, M.; Butola, B.S. 2013). Recently, multilayer nonwovens and three-dimensional textiles have been frequently used (Chang, C.W.; Chang, F.C. 2021; Gruyter, D. 2023). In our research, we focused on two-layer laminates, which are used for car seat upholstery and can be found on the top of car seats. These laminates are subjected to the different loads during their use, so their durability is very important (Reis, B. et al. 2022; Yuping, C.; Liu, Y.; Hong, H. 2022). In the study, two-layer laminates were produced, with one of the layers consisting of three-dimensional warp knitted fabric and the other of multilayer nonwoven. The laminates are produced in a dry lamination process on a static laminator at constant pressure and tempera-ture. A binder in the form of a powder and a thermoplastic web were used for the lamination (Reis, B. et al. 2022; Yuping, C.; Liu, Y.; Hong, H. 2022). The focus of the research was to investigate the influence of the structure of the individual layers of the laminate (three-dimensional knitted fabric and multilayer nonwoven) on the durability of the laminate. The research results showed that the integration of a three-dimensional knitted fabric has a significant effect on increasing the strength under compressive load with a ball. On the other hand, the three-dimensional knitted fabric in the laminate reduces the delamination force of the laminate. 2. EXPERIMENTAL 1.1 Materials The samples were laminated on a static laminator in a dry process for 15 seconds at a constant pressure of 3 bars and a temperature of 145°C. Sample 1 has a mass of 463 g/m2 and consists of a three-dimensional knitted fabric (vertical density of 20 rows per cm and horizontal density of 10 columns per cm) and a multilayer nonwoven fabric, and sample 2 with a mass of 413 g/m2 consists of a three-dimensional knitted fabric and a woven fabric (warp den-sity 32 threads/cm and weft density 10 threads/cm). Samples 3 and 4 have lower masses, 258 g/m2 and 184 g/m2. 227 29–30 May 2025, Ljubljana, Slovenia Samples 3 and 4 consist of a multilayered nonwoven (dry laid on roller carding machine, needle-bonded) and a woven fabric (warp density 32 threads/cm and weft density 10 threads/cm). A thermoplastic polypropylene mesh fabric was chosen as the binder for the lamination for sample 1 and a poly-amide powder for samples 2, 3 and 4 (Figure 1). Figure 1: Samples at 200x magnification 1.2 Methods The delamination force was determined according to DIN 54310 (Gruyter, D. 2023). The sample of laminate measuring 5 cm x 20 cm were produced. One layer of the laminate is first placed in the upper press and the lower press with other layer of the laminate is clamped on an Instron 5567 dynamometer. The speed of the upper press is 100 mm∙min-1. The breaking stress and deformation under compressive load with a ball was performed according to ASTM D3787 (Gruyter, D. 2023). The sample is compressed with a ball with a diameter of 4 cm until it breaks. The compressive force is expressed as a stress, taking into account the area of the 4.5 cm diameter opening. The deformation until breakage is also recorded. 2. RESULTS WITH DISCUSSION The results of the delamination force are shown in Figure 2, while the results of the breaking stress under com-pressive load are shown in Figure 3. 228 29–30 May 2025, Ljubljana, Slovenia Figure 2: The results of the delamination force (MD-machine direction; CD-cross machine direction) The results (Figure 2) show that sample 3 has the highest value for delamination force in the machine direction, while it has the lowest value in the cross-machine direction. Sample 4 exhibits the second highest delamination force in both directions. Both sample 3 and sample 4 consist of a multilayer nonwoven and woven fabric in which the binder is used in powder form. In sample 4, which also has the lowest mass, the binder is distributed more evenly during lamination, resulting in a similar value of delamination force in the machine and cross-machine directions. So exactly the opposite of sample 3, which has a higher mass, but the delamination force is much higher in the machine direction than in the cross-machine direction. The reason for this is due to the orientation of the fibres of the multilayered nonwoven, which is mainly longitudinal, for that it causes such a difference in the machine and cross-machine directions. Sample 2 shows the lowest value of delamination force in the longitudinal direction. Sample 2 consists of a 3D knitted fabric and a woven fabric bonded with a powdery binder. Sample 1, which consists of a 3D knitted fabric and a nonwoven fabric and is reinforced with a thermoplastic mesh, exhibits the lowest delamination force in both the machine and cross-machine directions, just like sample 2. The reason for this is the smooth surface of the 3D knitted fabric, which affects the poorer bonding between the individual layers and the binder in the form of powder or thermoplastic mesh fabric that we used in the lamination of samples 1 and 2. Figure 3: The results of the breaking stress under compressive load (MD-machine direction; CD-cross machine direction) 229 29–30 May 2025, Ljubljana, Slovenia The results show that samples 1 and 2, which contain 3D knitted fabrics (Figure 3), have higher values of the breaking stress under compressive load than samples 3 and 4, which consist of multilayer nonwovens. Sample 3 comes very close to the results of sample 2. The reason for this is the greater mass of sample 3 and the orientation of the fibres in the multilayer nonwoven. Sample 3 also shows the highest delamination force in the machine direction. The deformation results for determining the breaking stress under compressive load show that only sample 3 ex-hibited a deformation of more than 20 mm. Sample 4 had the lowest deformation values (less than 5 mm). Sample 3, which has the highest deformation, is made of a multilayer nonwoven and woven fabric and has a higher mass than sample 4. Due to its higher mass, the breaking stress and deformation under compressive loading with a ball of sample 3 are comparable to samples 1 and 2, which are made of a 3D knitted fabric. Sample 4, on the other hand, also has the lowest breaking stress and deformation under compressive loading with a ball due to its lower mass. 3. CONCLUSIONS Based on the study in which we investigated the influence of the structure of a single layer in two-layer laminates, in which we compared 3D knitted fabrics and multilayer nonwovens, we can conclude that laminates consisting of multilayer nonwovens have higher delamination force. In this case, the delamination force also depends on the orientation of the fibers in the nonwoven fabric. Lami-nates consisting of 3D knitted fabrics have significantly lower delamination force. The reason for this is the smooth surface of the 3D knitted fabric and the resulting poorer contact between the thermoplastic mesh fabric and the second layer, as in our case the nonwoven and the woven fabric (samples 1 and 2). In both cases, the lowest force was measured during delamination. In contrast, laminates with 3D knitted fabrics have a higher spherical compressive strength and deformation than those with multilayer nonwovens. Laminates that contain multilayer nonwovens with a mass per unit area of more than 250 g/m2 therefore also have a higher strength when subjected to a compressive load with a sphere and can replace laminates with 3D knitted fabrics. 4. REFERENCES: Chang, C.W.; Chang, F.C. (2021) Fracture Characteristics and Energy Dissipation of Textile Bamboo Fiber Reinforced Polymer. Polymers, 13, pp. 634. Gruyter, D. (2023) Smart and Functional Textiles. Oxfordshire: Taylor and Francis Group. Yuping, C.; Liu, Y.; Hong, H. (2022) ‘Deformation behavior of auxetic laminated fabrics with rotating square geometry’. Textile Research Journal, 92, pp. 4652-4665. Joshi, M., Butola, B.S. (2013) Application technologies for coating, lamination and finishing of technical textiles. London: Woodhead Publishing Series in Textiles, pp. 355-411. Reis, B. et al. (2022) Functional Design of Tri-Laminated Wool Fabrics Improving Comfort Properties’. In Journal of Biomimetics. Biomaterials and Biomedical Engineering, 57, pp. 65–76. Yuping, C.; Liu, Y.; Hong, H. (2022) ‘Deformation behavior of auxetic laminated fabrics with rotating square geometry’. Textile Research Journal, 92, pp. 4652-4665. 230 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author: Dunja Šajn Gorjanc Barbara Golja and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Aškerčeva 12 Aškerčeva 12 1000, Ljubljana, Slovenia 1000 Ljubljana, Slovenia Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana +386 1 2003230 barbara.golja@ntf.uni-lj.si +386 1 2003220 dunja.sajn@ntf.uni-lj.si 231 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION BIBLIOMETRIC ANALYSIS OF TEXTILE WASTE RESEARCH Danica Dolničar1 and Irena Sajovic1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The topic of textile waste, both pre- and post-consumer, solid textile waste and wastewater from textile production, has been studied due to environmental concerns, mainly due to volume, resource consumption and/ or toxicity. In our study, we use a bibliometric approach to investigate the thematic structure and current trends in textile waste research. The Scopus database was searched for the term textile waste and related terms over the last 12 years. The data was analysed with Bibliometrix/Biblioshiny and VOSviewer software. Documents, citations and keywords were examined. The results include annual production and citations, the most prolific/ influential authors and sources, and the most frequent keywords. The co-occurrence keyword network revealed clusters on textile wastewater treatment, mainly related to dye removal/degradation, and a cluster on solid textile waste. While wastewater remains a prevalent topic, circular economy, sustainability and waste management have become more frequent keywords in recent years. Dye/salt separation is the latest trend among wastewater treatment methods. Keywords: textile waste, textile wastewater, bibliometric analysis, science mapping 1. INTRODUCTION Textile waste includes textile materials (fibres, yarns, fabrics and garments) that are no longer usable or valuable (Anjimoon et al., 2024). It is divided into pre-consumer waste, which is generated during textile production and post-consumer waste, which is generated after the product has been used. It is a cause for concern primarily be-cause of its volume and resource consumption. Textile industry processes such as dyeing, printing and finishing also generate textile wastewater, which is characterised by its high volume and complex chemical composition (Kumar and Saravanan, 2017). Textile waste management and wastewater treatment are two highly researched topics. The aim of this study was to investigate the current structure and trends in the field of textile waste re-search using the bibliometric approach. So far, only a few bibliometric analyses have been conducted on the topic of textile waste (Kasavan et al., 2021), with some other works focusing on individual subtopics, e.g. textile waste-water treatment (Halepoto et al., 2022), circular economy (Hora et al., 2023) and green manufacturing (Sarker and Bartok, 2024). 2. EXPERIMENTAL The bibliometric methodology described by Donthu et al. (2021) was applied in our study. The approach involves two types of analysis: 1) performance analysis, which uses the number of documents/citations to identify the most prolific/influential units (e.g., authors, sources, and documents), and 2) science mapping, which aims to shed light on the topic structure through co-occurrence networks. The dataset for the analysis was obtained by searching the Scopus database using the search expression TITLE-ABS-KEY ((“textile* waste*” OR “cloth* waste*” OR “garment* waste*” OR “apparel* waste*” OR “fabric* waste*”)). A filter was applied to the document types (journal articles, reviews and conference papers) and the publication years from 2013 to 2024. The filtered search results were exported and transferred to Microsoft Excel where they were pre-processed. Duplicates were removed and a thesaurus was created for the author keywords to merge similar terms such as synonyms, abbreviations and variants. The final dataset comprised 5,001 documents. Microsoft Excel, Bibliometrix/Biblioshiny (Aria and Cuccurullo, 2017)fragmented, and controversial research streams. Science mapping is complex and unwieldly because it is multi-step and frequently requires numerous and diverse software tools, which are not all necessar-ily freeware. Although automated workflows that integrate these software tools into an organized data flow are emerging, in this paper we propose a unique open-source tool, designed by the authors, called bibliometrix, for 232 29–30 May 2025, Ljubljana, Slovenia performing comprehensive science mapping analysis. bibliometrix supports a recommended workflow to perform bibliometric analyses. As it is programmed in R, the proposed tool is flexible and can be rapidly upgraded and integrated with other statistical R-packages. It is therefore useful in a constantly changing science such as bib-liometrics.”,”container-title”:”Journal of Informetrics”,”ISSN”:”1751-1577”,”issue”:”4”,”journalAbbreviation”:”Jour-nal of Informetrics”,”page”:”959-975”,”source”:”ScienceDirect”,”title”:”Bibliometrix: An R-tool for comprehensive science mapping analysis”,”title-short”:”bibliometrix”,”volume”:”11”,”author”:[{“family”:”Aria”,”given”:”Mas-simo”},{“family”:”Cuccurullo”,”given”:”Corrado”}],”issued”:{“date-parts”:[[“2017”,11,1]]}}}],”schema”:”https://github. com/citation-style-language/schema/raw/master/csl-citation.json”} and VOSviewer (van Eck and Waltman, 2023) 29–30 May 2025, Ljubljana, Slovenia were used for data analysis and visualization of the results in the form of tables, charts and network diagrams. 3. RESULTS WITH DISCUSSION In the final dataset, the majority of documents were original research articles published in journals (85%), followed 3. RESULTS WITH DISCUSSION by conference papers (9.3%) and review articles (5.7%). In the final dataset, the majority of documents were original research articles published in journals (85%), 3.1 Documents followed by conference papers (9.3%) and review articles (5.7%). 3.1 Documents ument and year. The number of published documents showed an average annual growth rate of 16.3%, with the The annual scientific production is shown in Figure 1, which also shows the number of total citations (TC) per document and year. The number of published documents showed an average annual growth The annual scientific production is shown in Figure 1, which also shows the number of total citations (TC) per doc- from 2020 had the highest average citation rate per document per year (7.7). rate of 16.3%, with the highest value reached in 2019 (39.4%). The average document was 4.7 years highest value reached in 2019 (39.4%). The average document was 4.7 years old and had 25.6 citations. Articles old and had 25.6 citations. Articles from 2020 had the highest average citation rate per document per year (7.7). 1000 9 s 800 7 ear 700 900 8 um 500 /doc 4C 400 oc 3 D 300 2 ent 600 5 6 ./y 200 Mean t 100 1 0 0 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Publication year Documents Mean TC/doc./year Figure 1: Figure 1 : Production over time (number of documents), and mean of total citations (TC) Production over time (number of documents), and mean of total citations (TC) Four documents from our dataset were cited more than 1000 times each in Scopus. A further eight were cited over Four documents from our dataset were cited more than 1000 times each in Scopus. A further eight were 500 times. Ten of these 12 documents are review articles, only two contain original research. Similarly, 11 of the cited over 500 times. Ten of these 1 2 documents are review articles, only two contain original research. most cited articles relate to the topic of textile wastewater treatment, while the remaining article focuses on the Similarly, 11 of the most cited articles relate to the topic of textile wastewater treatment, while the impact of fast fashion (Niinimäki et al., 2020)however, the industry continues to grow, in part due to the rise of fast remaining article focuses on the impact of fast fashion (Niinimäki et al., 2020) . The single most cited fashion, which relies on cheap manufacturing, frequent consumption and short-lived garment use. In this Review, article (Holkar et al., 2016) provides an overview of textile wastewater treatment methods. The we identify the environmental impacts at critical points in the textile and fashion value chain, from production to predominant topic is dye removal/degradation, which is covered in seven titles, e.g. (Al-Tohamy et al., consumption, focusing on water use, chemical pollution, CO2 emissions and textile waste. Impacts from the fash 2022). - the basis of these environmental impacts, we outline the need for fundamental changes in the fashion business 3.2 Authors ion industry include over 92 million tonnes of waste produced per year and 79 trillion litres of water consumed. On model, including a deceleration of manufacturing and the introduction of sustainable practices throughout the There were 1 4899 contributing authors, with an average of 4.7 co-authors per paper, while 1 60 authors supply chain, as well a shift in consumer behaviour — namely, decreasing clothing purchases and increasing published 189 (3. 8%) papers as single authors. Fifty-six authors published 10 or more documents. The garment lifetimes. These changes stress the need for an urgent transition back to ‘slow’ fashion, minimizing and publication timeline and influence of the 11 most productive authors (with 15 or more documents) was mitigating the detrimental environmental impacts, so as to improve the long-term sustainability of the fashion visualised using Biblioshiny (Figure 2 ). Sabir Hussain is in the lead with 24 documents, followed by B art supply chain.”,”container-title”:”Nature Reviews Earth & Environment”,”ISSN”:”2662-138X”,”issue”:”4”,”journal Van der Bruggen (22), Munawar Aqeel Iqbal (19) and Nadir Dizge (18 documents). One author started - publishing in 2019. Based on the colour intensity of the dots representing the citations in Figure 2, we can see notable peaks in 2019 (three authors with documents with more than 100 citations per year) and in 2022 (one such author). The 11 authors mentioned above published a total of 157 documents. Thematically, more than half of the titles contain the term wastewater. The keyword textile wastewater 233 was used by 9 authors, photocatalysis and textile wastewater treatment by 6, decolorization and adsorption by 5, dye/salt separation by 4, azo dyes and biodegradation by 2 authors. Thirty-five authors have more than 1,000 total citations each. Munawar Aqeel Iqbal and Bart Van der Bruggen, who are 29–30 May 2025, Ljubljana, Slovenia Abbreviation”:”Nat Rev Earth Environ”,”language”:”en”,”page”:”189-200”,”source”:”www.nature.com”,”title”:”The environmental price of fast fashion”,”volume”:”1”,”author”:[{“family”:”Niinimäki”,”given”:”Kirsi”},{“family”:”Peters”,”-given”:”Greg”},{“family”:”Dahlbo”,”given”:”Helena”},{“family”:”Perry”,”given”:”Patsy”},{“family”:”Rissanen”,”giv-en”:”Timo”},{“family”:”Gwilt”,”given”:”Alison”}],”issued”:{“date-parts”:[[“2020”,4]]}}}],”schema”:”https://github.com/ citation-style-language/schema/raw/master/csl-citation.json”} . The single most cited article (Holkar et al., 2016) provides an overview of textile wastewater treatment methods. The predominant topic is dye removal/degra-dation, which is covered in seven titles, e.g. (Al-Tohamy et al., 2022)the continuous discharge of wastewater from a large number of textile industries without prior treatment has significant negative consequences on the environment and human health. Textile dyes contaminate aquatic habitats and have the potential to be toxic to aquatic organisms, which may enter the food chain. This review will discuss the effects of textile dyes on water bodies, aquatic flora, and human health. Textile dyes degrade the esthetic quality of bodies of water by increasing biochemical and chemical oxygen demand, impairing photosynthesis, inhibiting plant growth, entering the food chain, providing recalcitrance and bioaccumulation, and potentially promoting toxicity, mutagenicity, and carcino-genicity. Therefore, dye-containing wastewater should be effectively treated using eco-friendly technologies to avoid negative effects on the environment, human health, and natural water resources. This review compares the most recent technologies which are commonly used to remove dye from textile wastewater, with a focus on the advantages and drawbacks of these various approaches. This review is expected to spark great interest among the research community who wish to combat the widespread risk of toxic organic pollutants generated by the tex-tile industries.”,”container-title”:”Ecotoxicology and Environmental Safety”,”ISSN”:”0147-6513”,”journalAbbrevia-tion”:”Ecotoxicology and Environmental Safety”,”page”:”113160”,”source”:”ScienceDirect”,”title”:”A critical review on the treatment of dye-containing wastewater: Ecotoxicological and health concerns of textile dyes and possible remediation approaches for environmental safety”,”title-short”:”A critical review on the treatment of dye-containing wastewater”,”volume”:”231”,”author”:[{“family”:”Al-Tohamy”,”given”:”Rania”},{“family”:”Ali”,”given”:”Sameh S.”},{“-family”:”Li”,”given”:”Fanghua”},{“family”:”Okasha”,”given”:”Kamal M.”},{“family”:”Mahmoud”,”given”:”Yehia A. -G.”},{“family”:”Elsamahy”,”given”:”Tamer”},{“family”:”Jiao”,”given”:”Haixin”},{“family”:”Fu”,”given”:”Yinyi”},{“fami-ly”:”Sun”,”given”:”Jianzhong”}],”issued”:{“date-parts”:[[“2022”]]}}}],”schema”:”https://github.com/citation-style-lan-guage/schema/raw/master/csl-citation.json”} . 3.2 Authors There were 14899 contributing authors, with an average of 4.7 co-authors per paper, while 160 authors published 189 (3.8%) papers as single authors. Fifty-six authors published 10 or more documents. The publication timeline and influence of the 11 most productive authors (with 15 or more documents) was visualised using Biblioshiny (Figure 2). Sabir Hussain is in the lead with 24 documents, followed by Bart Van der Bruggen (22), Munawar Aqeel Iqbal (19) and Nadir Dizge (18 documents). One author started publishing in 2019. Based on the colour intensity of the dots representing the citations in Figure 2, we can see notable peaks in 2019 (three authors with documents with more than 100 citations per year) and in 2022 (one such author). The 11 authors mentioned above published a total of 157 documents. Thematically, more than half of the titles contain the term wastewater. The keyword textile wastewater was used by 9 authors, photocatalysis and textile wastewater treatment by 6, decolorization and adsorption by 5, dye/salt separation by 4, azo dyes and biodegradation by 2 authors. Thirty-five authors have more than 1,000 total citations each. Munawar Aqeel Iqbal and Bart Van der Bruggen, who are also among the most prolific authors, are the most cited authors with 2138 and 2005 total citations respectively. Iqbal published the most articles on absorption and biodegradation, while Van der Bruggen researched the dye/salt separation. 16 other authors have more than 1500 citations each, but with less than 15 documents per person (resulting in more than 100 citations per document). 234 29–30 May 2025, Ljubljana, Slovenia Figure 2: Publication timeline for the 11 most productive authors (dot size = number of documents, dot colour intensity = number of citations); visualisation: Biblioshiny 3.3 Sources Ten of the top 11 sources with more than 61 published documents in our dataset are journals and the remaining source is a conference (Table 1). All sources except one publish in the Environmental Science Scopus subcate-gory. Table 1: Ten most productive sources (TC = total citations) Rank Scopus TC/ Source Doc. TC subcategories Doc. 1 Desalination and Water Treatment Env. Sci., Eng. 179 1912 10.7 2 Environmental Science and Pollution Re- Env. Sci. 118 3295 27.9 search 3 Journal of Cleaner Production Env. Sci., Eng., Ener., 113 6286 55.6 Bus. 4 Journal of Environmental Chemical Engi- Env. Sci., Chem. Eng. 100 4866 48.7 neering 5 Journal of Water Process Engineering Env. Sci., Eng., Chem. 93 2691 28.9 Eng., Biochem. 6 Chemosphere Env. Sci., Chem., Med. 75 3760 50.1 7 Chemical Engineering Journal Env. Sci., Eng., Chem. 72 6281 87.2 Eng., Chem. 8 Journal of Environmental Management Env. Sci., Bus., Econ. 68 5684 83.6 9 Separation and Purification Technology Chem. Eng., Chem. 62 3131 50.5 10 IOP Conference Series: Earth and Environ- Env. Sci., Earth & Plan. 62 267 4.3 mental Science Sci. 11 Water Science and Technology (20) Env. Sci. 62 1184 19.1 235 29–30 May 2025, Ljubljana, Slovenia The journal Desalination and Water Treatment has by far the most documents (179) 29–30 May 2025, Ljubljana, Slovenia . Nine sources are also in the top 10 by number of total citations, although the most productive source is only the 14th most cited. The Journal of Cleaner Production and the Chemical Engineering Journal are the leaders in terms of total citations (6286 and 6281 respectively). The latter also has the most total citations per article (87.2) while the Earth and Environmental Science conference is the least cited (4.3). of total citations (6286 and 6281 respectively). The latter also has the most total citations per article (87.2) while the Earth and Environmental Science conference is the least cited (4.3). 3.4 Topics 3.4 Topics The author keywords were present in 91.06% of the documents, while the keywords added by Scopus were only The author keywords were present in 91. 06 % of the documents, while the keywords added by Scopus present in 71.63%, therefore the former were taken into account in this study. The ten most frequent keywords were only present in 7 1. 63 %, therefore the former were taken into account in this study. The ten most are listed in Figure 3. frequent keywords are listed in Figure Textile wastewater 3 was by far the most frequent keyword. The oldest keyword in the top . Textile wastewater was by far the most frequent keyword. The 10 was oldest keyword in decolorization the top 10 (APY – avg. publication year 2018.7) and the most recent was was decolorization (APY – avg. publication year 2018.7 circular economy ) and the most (2022.1). Eight out of 10 keywords relate to liquid waste from textile processing, while the remaining two mainly relate to recent was circular economy (2022.1). Eight out of 10 keywords relate to liquid waste from textile solid textile waste. processing, while the remaining two mainly relate to solid textile waste. circular economy 151 dyes 175 azo dyes 182 recycling 184 wastewater 189 wastewater treatment 202 decolorization 248 textile waste 340 adsorption 400 textile wastewater 1027 0 200 400 600 800 1000 1200 Figure 3: Figure 3: Ten most frequent author keywords Ten most frequent author keywords Next, we analysed the first 30 keywords (frequency higher than 71) and grouped them by topic (the Next, we analysed the first 30 keywords (frequency higher than 71) and grouped them by topic (the terms are terms are listed in decreasing frequency): 1) wastewater treatment methods (8 keywords: adsorption, listed in decreasing frequency): 1) electrocoagulation, advanced oxidation, photocatalysis, activated carbon, biodegradation, wastewater treatment methods (8 keywords: adsorption, electrocoagulation, advanced oxidation, photocatalysis, activated carbon, biodegradation, photodegradation, bioremediation photodegradation, bioremediation ), 2 ) dyes/decolorization (7 keywords: decolorization, azo dyes, dyes, ), 2) dyes/ decolorization methylene blue, dye removal, color removal, textile dyes (7 keywords: decolorization, azo dyes, dyes, methylene blue, dye removal, color removal, textile ), 3) wastewater (5 keywords: textile dyes wastewater, wastewater treatment, wastewater, textile effluent, textile wastewater treatment ), 3) wastewater (5 keywords: textile wastewater, wastewater treatment, wastewater, textile effluent, textile ), 4) solid wastewater treatment waste (4 keywords: ), 4) textile waste, recycling, circular economy, sustainability solid waste (4 keywords: textile waste, recycling, circular economy, sustainability ). The remaining 6 keywords ). The remaining 6 keywords were either general (textiles, textile industry) or related to wastewater treatment methods were either general (textiles, textile industry) or related to wastewater treatment methods (response (response surface methodology, kinetics, COD, isotherms). Among the last 20 keywords, surface methodology, kinetics, COD, isotherms). Among the last 20 keywords, sustainability sustainability was the was the newest (APY 2021.6) and newest (APY 2021.6) and color removal color removal the oldest (APY 2018.5). the oldest (APY 2018.5). To investigate the thematic structure, VOSviewer was used to create a co-occurrence network for the To investigate the thematic structure, VOSviewer was used to create a co-occurrence network for the 161 most obtained are identified by different colors, with the dot size corresponding to the keyword frequency. For 161 most frequent author keywords with a frequency of 15 or more (Figure 4). The six keyword clusters frequent author keywords with a frequency of 15 or more (Figure 4). The six keyword clusters obtained are iden-each cluster, the most frequent word and the most prominent keywords are listed grouped by topic, tified by different colors, with the dot size corresponding to the keyword frequency. For each cluster, the most focusing on methods and processes: 1) textile wastewater (red cluster, 38 keywords): frequent word and the most prominent keywords are listed grouped by topic, focusing on methods and process-electrocoagulation, advanced oxidation, electrochemical treatment, electrochemical oxidation es: 1) (methods); textile wastewater (red cluster, 38 keywords): electrocoagulation, advanced oxidation, electrochemical dye degradation, color removal, reactive black 5 (dyes/removal); COD – chemical oxygen treatment, electrochemical oxidation (methods); dye degradation, color removal, reactive black 5 (dyes/removal); demand (parameters); 2) adsorption (green cluster; 32 keywords): photocatalysis, activated carbon, COD – chemical oxygen demand photodegradation, electrospinning (parameters); 2) (methods/processes); adsorption congo red, methylene blue, methyl orange (green cluster; 32 keywords): photocatalysis, activated carbon, photodegradation, electrospinning (dyes); 3) textile waste (blue cluster, 31 keywords): (methods/processes); recycling, reuse (methods), congo red, methylene blue, methyl or-circular economy, ange sustainability (practices), waste management (dyes); 3) textile waste (blue cluster, 31 keywords): , environment recycling, reuse (general); 4) (methods), decolorization circular economy, sustain- (yellow cluster, ability (practices), waste management 27 keywords): biodegradation, bioremediation, biosorption, phytoremediation , environment (general); 4) decolorization (yellow cluster, 27 keywords): (methods); azo dyes, biodegradation, bioremediation, biosorption, phytoremediation dyes, textile dyes (dyes); wastewater (general); 5) wastewater treatment (methods); azo dyes, dyes, textile dyes ( purple cluster , 21 keywords): (dyes); wastewater nanofiltration, dye/salt separation, desalination (general); 5) (methods); dye removal, dye/salt separation wastewater treatment ( purple cluster, 21 keywords): nanofiltration, dye/salt separation, (dyes/removal); textile wastewater treatment, textile industry (general); 6) reactive dyes (light blue, 12 keywords): coagulation, dye adsorption; flocculation (methods); chitosan (material); industrial wastewaters (general). 236 4 29–30 May 2025, Ljubljana, Slovenia desalination (methods); dye removal, dye/salt separation (dyes/removal); textile wastewater treatment, textile in-dustry (general); 6) reactive dyes (light blue, 12 keywords): coagulation, dye adsorption; flocculation (methods); chitosan (material); industrial wastewaters (general). The slightly offset blue cluster mainly contains terms that refer to solid waste, while the other five clusters are strongly related to textile wastewater and its treatment methods. Another common group of words found in these clusters are specific dyes and/or processes related to dye removal. Keywords at the edges of the network visuali-sation diagram (e.g. from the purple cluster) indicate niche topics that are less related to other concepts, while the main topics remain in the middle of the diagram (green, red and yellow clusters). The last cluster (coloured light blue) overlaps strongly with other clusters. Figure 4: Main research topics by keyword network; visualisation: VOSviewer Another type of topic visualization, a thematic map, was created with Biblioshiny, based on centrality and density calculations (Figure 5). The centrality of a cluster/topic is related to the number of connections with other clusters and reflects the cluster’s relevance, while the density reflects the interconnectedness within the topic itself and indicates the degree of development. In our analysis, 161 keywords with a minimum frequency of 15 were con-sidered. Next, we draw parallels between the two representations. The two largest clusters (circles) in Figure 4 represent two of three motor (relevant and well-developed) themes and both relate to dye removal/degradation methods in textile wastewater. Cluster 1 (leading keyword textile wastewater) comprises 64 keywords, including treatment methods such as electrocoagulation, coagulation, advanced oxidation, biodegradation and bioremediation, cor-responding to the combined red, yellow and most of the light blue clusters in Figure 3. Cluster 2 (adsorption, 49 keywords), which deals with adsorption and photocatalysis processes, is largely associated with the green cluster in Figure 3. The third motor theme, characterised by cluster 3 (textile waste, 17 keywords), focuses on solid waste and includes terms such as recycling, circular economy and waste management. These are part of the blue clus-ter in Figure 3. In the same blue cluster we find the keywords from cluster 4 (textiles, 14 keywords) of the thematic map, which also deals with solid waste and contains keywords about reuse and pyrolysis, as well as materials such as cotton, cellulose and composites. Clusters 5–7 (textile wastewater treatment – 11 keywords, dye/salt separation – 3 keywords, antifouling – 2 keywords) shown on the left-hand side of the map in Figure 3 (indicating 237 29–30 May 2025, Ljubljana, Slovenia low connectivity with other topics) all relate to filtration of wastewater (ultra/nanofiltration/loose nanofiltration, de-salination, dye/salt separation), which corresponds well to the purple cluster in Figure 4. The only term in cluster 8 (mechanical properties) is found in the blue cluster in Figure 4 together with other solid waste. Figure 5: Thematic map of main research topics by author keywords; visualisation: Biblioshiny To identify trends and emerging research topics, we looked for the keywords whose relative frequency has in-creased over the last four years (2021–2024). During this period, 56% of the documents in our dataset were published. Using the chi-square test, we identified the following top 10 keywords with a total frequency of at least 30: dye/salt separation (96% instead of the expected 56% in the last four years), circular economy (81%), cellulose (81%), graphene oxides (79%), waste management (78%), polyesters (77%), sustainability (76%), life cycle assessment (72%), textile waste (68%) and recycling (66%). It can be seen that the terms are related to solid waste, reducing resource consumption (circular economy, sustainability), smart textiles (graphene oxides) and filtration (dye/salt separation). Conversely, some keywords appeared less frequently than expected in the last 4 years. These were related to certain dye removal methods such as coagulation and biosorption as well as keywords related to chemical oxygen demand. Despite this trend, documents on wastewater treatment continue to outnumber articles dealing with solid waste. Thematically, the most influential documents related to single wastewater treatments methods deal with photoca-talysis (Ajmal et al., 2014), advanced oxidation (Asghar et al., 2015), and adsorption (Kausar et al., 2018), while the most cited article on solid waste concerns fast fashion (Niinimäki et al., 2020)however, the industry continues to grow, in part due to the rise of fast fashion, which relies on cheap manufacturing, frequent consumption and short-lived garment use. In this Review, we identify the environmental impacts at critical points in the textile and fashion value chain, from production to consumption, focusing on water use, chemical pollution, CO2 emissions and textile waste. Impacts from the fashion industry include over 92 million tonnes of waste produced per year and 79 trillion litres of water consumed. On the basis of these environmental impacts, we outline the need for fundamental changes in the fashion business model, including a deceleration of manufacturing and the introduction of sustain-able practices throughout the supply chain, as well a shift in consumer behaviour — namely, decreasing clothing purchases and increasing garment lifetimes. These changes stress the need for an urgent transition back to ‘slow’ fashion, minimizing and mitigating the detrimental environmental impacts, so as to improve the long-term sustain-ability of the fashion supply chain.”,”container-title”:”Nature Reviews Earth & Environment”,”ISSN”:”2662-138X”,”is-sue”:”4”,”journalAbbreviation”:”Nat Rev Earth Environ”,”language”:”en”,”page”:”189-200”,”source”:”www.nature. com”,”title”:”The environmental price of fast fashion”,”volume”:”1”,”author”:[{“family”:”Niinimäki”,”given”:”Kirsi”},{“-family”:”Peters”,”given”:”Greg”},{“family”:”Dahlbo”,”given”:”Helena”},{“family”:”Perry”,”given”:”Patsy”},{“fami-ly”:”Rissanen”,”given”:”Timo”},{“family”:”Gwilt”,”given”:”Alison”}],”issued”:{“date-parts”:[[“2020”,4]]}}}],”sche-ma”:”https://github.com/citation-style-language/schema/raw/master/csl-citation.json”} . All of the above examples have over 700 citations. Outside of the predominant wastewater topic, another article on circular fashion/economy 238 29–30 May 2025, Ljubljana, Slovenia (Shirvanimoghaddam et al., 2020) stands out with 333 citations. A paper on dye/salt separation (Tavangar et al., 2020)while contact angle measurements confirmed improved membrane hydrophilicity. The performances of the membranes were tested by aqueous dye solutions viz., Direct Red 23, Congo Red, and Direct Red 243 as well as real textile wastewater. Low rejection rates were observed for different aqueous salt solutions following the sequence: MgSO4 (4.1% was also cited nearly 300 times. Examples of more recent influential research (26 ar-ticles with 40–110 citations) include 5 review articles on wastewater treatment related to dye removal, e.g. (Valli Nachiyar et al., 2023)2023, an article on cotton waste recycling and an article on plastic waste management. Eight out of 19 titles of original research mention adsorption, three of which refer to activated carbon developed from plants, e.g. (Fito et al., 2023). Nine documents are related to the use of nanotechnology in wastewater treatment (4 related to adsorption, 3 to filtration and 2 to (photo)degradation). One such example concerns graphene oxide used in nanocomposite membranes (Jafarian et al., 2023). The most frequently cited work in the last two years deals with the use of textile waste materials in supercapacitors (Fan et al., 2023). 4. CONCLUSIONS The study examined the textile waste research field using two methodological approaches: performance analy-sis and science mapping. Data from the Scopus database for the period from 1913 to 2024 were analysed and visualised using Microsoft Excel, Bibliometrix/Biblioshiny and VOSviewer. The number of articles, conference papers and review articles showed an increasing trend in new documents, and four documents from our dataset received more than 1000 citations each. Thematically, the most influential documents related to unique wastewa-ter treatment methods deal with photocatalysis, advanced oxidation and adsorption, while the most cited article on solid waste concerns fast fashion. The most productive author was Sabir Hussain with 24 documents, while Munawar Aqeel Iqbal and Bart Van der Bruggen were the most cited with over 2000 citations. The most (179) papers were published in the journal Desalination and Water Treatment, while the Journal of Cleaner Produc-tion and the Chemical Engineering Journal lead in total citations (over 6000). The co-occurrence network of author keywords revealed six clusters of related concepts, one containing keywords related to solid waste, while the remaining five clusters deal with textile wastewater and its treatment methods. To identify trends and emerging research topics, we searched for the keywords that have increased in relative frequency over the last four years (2021–2024). These keywords relate to resource consumption (sustainability, circular economy), smart textiles (graphene oxides) and filtration (dye/salt separation). The latest articles deal with the use of nanotechnology in wastewater treatment. 5. REFERENCES Ajmal, A., Majeed, I., Naseem Malik, R., Idriss, H., and Amtiaz Nadeem, M. 2014. ‘Principles and Mechanisms of Photocatalytic Dye Degradation on TiO2 Based Photocatalysts: A Comparative Overview’. RSC Advances 4 (70): 37003–26. Al-Tohamy, R., Ali, S.S., Li, F., Okasha, K.M., Mahmoud, Y.A.-G., Elsamahy, T., Jiao, H., Fu, Y., and Sun, J. 2022. ‘A Critical Review on the Treatment of Dye-Containing Wastewater: Ecotoxicological and Health Concerns of Textile Dyes and Possible Remediation Approaches for Environmental Safety’. Ecotoxicology and Environmental Safety 231:113160. Anjimoon, S., V, A., Gurnani, J., Khan, I., Paul, S., and Al-Jawahry, H.M. 2024. ‘Innovations and Opportunities in Sustainable Textile Recycling’. E3S Web of Conferences 507:01065. Aria, M., and Cuccurullo, C. 2017. ‘Bibliometrix: An R-Tool for Comprehensive Science Mapping Analysis’. Journal of Informetrics 11 (4): 959–75. Asghar, A., Abdul Raman, A.A., and Wan Daud, W.M.A. 2015. ‘Advanced Oxidation Processes for in-Situ Production of Hydrogen Peroxide/ Hydroxyl Radical for Textile Wastewater Treatment: A Review’. Journal of Cleaner Production 87:826–38. Donthu, N., Kumar, S., Mukherjee, D., Pandey, N., and Lim, W.M. 2021. ‘How to Conduct a Bibliometric Analysis: An Overview and Guidelines’. Journal of Business Research 133:285–96. Eck, N.J. van, and Waltman, L. 2023. VOSviewer Manual: Manual for VOSviewer Version 1.6.19. Leiden, The Nederlands: Universiteit Leiden. https://www.vosviewer.com/documentation/Manual_VOSviewer_1.6.20.pdf. Fan, W., Wang, Q., Rong, K., Shi, Y., Peng, W., Li, H., Guo, Z., et al. 2023. ‘MXene Enhanced 3D Needled Waste Denim Felt for High-Performance Flexible Supercapacitors’. Nano-Micro Letters 16 (1): 36. Fito, J., Abewaa, M., Mengistu, A., Angassa, K., Ambaye, A.D., Moyo, W., and Nkambule, T. 2023. ‘Adsorption of Methylene Blue from Textile Industrial Wastewater Using Activated Carbon Developed from Rumex Abyssinicus Plant’. Scientific Reports 13 (1): 5427. 239 29–30 May 2025, Ljubljana, Slovenia Halepoto, H., Gong, T., and Memon, H. 2022. ‘Current Status and Research Trends of Textile Wastewater Treatments—A Bibliometric-Based Study’. Frontiers in Environmental Science 10:1–18. Holkar, C.R., Jadhav, A.J., Pinjari, D.V., Mahamuni, N.M., and Pandit, A.B. 2016. ‘A Critical Review on Textile Wastewater Treatments: Possible Approaches’. Journal of Environmental Management 182:351–66. Hora, S.T., Bungau, C., Negru, P.A., and Radu, A.-F. 2023. ‘Implementing Circular Economy Elements in the Textile Industry: A Bibliometric Analysis’. Sustainability 15 (20): 15130. Jafarian, H., Dadashi Firouzjaei, M., Aghapour Aktij, S., Aghaei, A., Pilevar Khomami, M., Elliott, M., Wujcik, E.K., Sadrzadeh, M., and Rahimpour, A. 2023. ‘Synthesis of Heterogeneous Metal Organic Framework-Graphene Oxide Nanocomposite Membranes for Water Treatment’. Chemical Engineering Journal 455:140851. Kasavan, S., Yusoff, S., Guan, N.C., Zaman, N.S.K., and Fakri, M.F.R. 2021. ‘Global Trends of Textile Waste Research from 2005 to 2020 Using Bibliometric Analysis’. Environmental Science and Pollution Research 28 (33): 44780–94. Kausar, A., Iqbal, M., Javed, A., Aftab, K., Nazli, Z.-H., Bhatti, H.N., and Nouren, S. 2018. ‘Dyes Adsorption Using Clay and Modified Clay: A Review’. Journal of Molecular Liquids 256:395–407. Kumar, P.S., and Saravanan, A. 2017. ‘Sustainable Wastewater Treatments in Textile Sector’. In Sustainable Fibres and Textiles, edited by Subramanian Senthilkannan Muthu, 323–46. The Textile Institute Book Series. Woodhead Publishing. Niinimäki, K., Peters, G., Dahlbo, H., Perry, P., Rissanen, T., and Gwilt, A. 2020. ‘The Environmental Price of Fast Fashion’. Nature Reviews Earth & Environment 1 (4): 189–200. Saravanan, R., Karthikeyan, S., Gupta, V.K., Sekaran, G., Narayanan, V., and Stephen, A. 2013. ‘Enhanced Photocatalytic Activity of ZnO/ CuO Nanocomposite for the Degradation of Textile Dye on Visible Light Illumination’. Materials Science and Engineering: C 33 (1): 91–98. Sarker, Md.S.I., and Bartok, I. 2024. ‘Global Trends of Green Manufacturing Research in the Textile Industry Using Bibliometric Analysis’. Case Studies in Chemical and Environmental Engineering 9:100578. Shirvanimoghaddam, K., Motamed, B., Ramakrishna, S., and Naebe, M. 2020. ‘Death by Waste: Fashion and Textile Circular Economy Case’. Science of The Total Environment 718:137317. Tavangar, T., Karimi, M., Rezakazemi, M., Reddy, K.R., and Aminabhavi, T.M. 2020. ‘Textile Waste, Dyes/Inorganic Salts Separation of Cerium Oxide-Loaded Loose Nanofiltration Polyethersulfone Membranes’. Chemical Engineering Journal 385:123787. Valli Nachiyar, C., Rakshi, A.D., Sandhya, S., Britlin Deva Jebasta, N., and Nellore, J. 2023. ‘Developments in Treatment Technologies of Dye-Containing Effluent: A Review’. Case Studies in Chemical and Environmental Engineering 7:100339. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Danica Dolničar Irena Sajovic Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering University of Ljubljana University of Ljubljana Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška 5 SI-1000, Ljubljana, Slovenia Snežniška 5 SI-1000, Ljubljana, Slovenia +386 1 2003 254 irena.sajovic@ntf.uni-lj.si +386 1 2003 276 danica.dolnicar@ntf.uni-lj.si 240 COMFORT AND QUALITY CONTROL OF TEXTILES 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION INFLUENCE OF THE WOVEN FABRICS SURFACE HAIRINESS ON THEIR ELECTRICAL RESISTANCE UNDER DIFFERENT ATMOSPHERIC CONDITIONS Juro Živičnjak1 and Antoneta Tomljenović1 1University of Zagreb, Faculty of Textile Technology, Croatia Abstract: The high value of textile materials electrical resistance can lead to accumulation of electrostatic charge on its surface. There are many factors that influence the accumulation of electrostatic charge on textiles, such as: yarn type, fabric structure, thickness, moisture content, porosity or the addition of surface pretreatment, but the surface hairiness of textiles, caused by protruding fibers is usually overlooked property. Therefore, this study investigates the influence of height of materials surface hairiness layer to its electrical resistance at different atmospheric conditions, by calculating it residual electrical resistance. The height of materials surface hairiness layer was assessed on the image taken via camera of digital microscope (Dino-Lite), while the materials electrical resistance values were measured according to the European standard methods for surface resistivity (r) EN 1149-1 and vertical resistance (R) EN 1149-2. Keywords: hairiness, surface resistivity, vertical resistance, relative humidity, woven fabrics 1. INTRODUCTION The accumulation of electrostatic charge on the surface of textiles is a widespread phenomenon that becomes more visible in winter when the air humidity is low, in a form of a spark. The greater the amount of electrostatic charge that can accumulate on materials surface the higher the probability of electrostatic discharge (ESD). In most situations it is harmless and can do no serious damage, but at gas stations or certain work environments it can cause fire, explosions or do serious damage to electronic devices (Abo-Basha 2024; Paasi 2005; 2002; Welker 2005; Nurmi 2007)in order to minimise the device failures due to electrostatic discharge (ESD. The accu-mulation of electrostatic charge in textile materials is usually caused by direct physical contact or friction between two surfaces, which occurs frequently in their everyday use. During contact or friction between two textile mate-rials, the electron transfer occurs, from the surface of one material to the surface of the other material, especially if they are made from different type of fibers. Electron transfer causes the materials surfaces to become electrically unbalanced, and positively “+” or negatively “-“charged. The positively charged material is a material from which the electrons have been transferred, while the negatively charged material is a material to which they have been transferred. The direction of electron transfer between two materials depends on their type, more specific their triboelectric property. The textile materials triboelectric property is described in the Triboelectric series, where tex-tile fibers are distributed between a positive “+”, and a negative “-“ end. The closer the fiber in Triboelectric series is to the positive end the more inclined is to releasement of electrons, while the fibers closer to negative end are more inclined to acceptance of electrons (Nurmi 2007; Kim 2021). Textile materials that are susceptible to the accumulation of electrostatic charge are usually made of less electro conductive, synthetic fibers, which generally absorb a small amount of moisture and have high electrical resistance (Hałgas 2024). The accumulation of elec-trostatic charge is not limited to the materials made from synthetic fibers or fibers with low moisture content, but it also can occur on materials made of different type of fibers in atmospheres with low air humidity (Zhu 2013; Var-naite-Žuravliova 2013; Salvado 2012)as well as their advantages and disadvantages. And the correlation study on different standards showed that testing results of different materials according to the same method had similar change trend, but no evidence proved a definite linear relationship of three test methods. © (2013. Therefore, when the material propensity to the accumulation of electrostatic charge is determined is often done by measuring it electrical resistance. In Europe, the electrical resistance of textile materials is determined by two EN 1149 stan- 242 29–30 May 2025, Ljubljana, Slovenia dard test methods, first EN 1149-1 for surface resistivity (r) and second EN 1149-2 for vertical resistance (R). This European standards are meant for testing the electrostatic dissipative protective clothing or fabrics. The standards contain information on the test method, materials requirements, and the atmospheric conditions under which the specimen and the test method should be carried out, i.e. at a temperature of 23 ± 1 °C and a relative humidity of 25 ± 5 %. In reality, in addition to the atmospheric conditions that influence the accumulation of electrostatic charge on textiles, there are many other factors that have been researched over the years, such as the type of yarn, the fabric structure, surface roughness, the thickness, the moisture content, the porosity or the addition of any type of pretreatment (Hong 2020; Abo-Basha 2024; Sereda 1964; Nurmi 2007; Varnaite 2009; Asanovic 2022). The most overlooked factor when it comes to determining the textile materials tendency to accumulate electrostatic charges is their surface appearance, more precisely materials surface hairiness caused by protruding fibers. The-refore, this study investigates the influence of materials surface hairiness to its electrical resistance, by performing measurements of materials surface resistivity and vertical resistance under different atmospheric conditions. The study was performed on selected reference woven fabric made of cotton, viscose, polyamide 6.6 and polyester (PET) fibers, and the height of their surface hairiness layer was determined on the image obtained via camera of digital microscope (Dino-Lite). 2. EXPERIMENTAL 2.1 Materials Samples of single fiber cotton, staple viscose, polyamide 6.6 and polyester (PET) colorless reference adjacent fabrics, in plain weave, which are used for color fastness testing (ISO 105-F series) of textile materials, were selected for this study. Selected fabrics do not contain chemically damaged fibers, residues of finishing agents, dyes or fluorescent brighteners. The values of fabrics mass per unit area (ISO 3801:1977) and thickness (EN ISO 5084:1996) were determined according to the standard methods. For the purpose of this study, three circular specimens with a diameter of 140 mm were cut from each fabric. During testing, values for mass, thickness and moisture content (ASTM D2654-22) were determined for each specimen and each atmospheric condition under which it was conditioned. 2.2 Fabric surface hairiness The height of the surface hairiness of the fabric, expressed in millimeters, was determined for each prepared spe-cimen using the digital image of the surface (Fig. 1c) taken with the camera of the digital microscope. The digital image of the specimen surface had to be converted to black and white image so that the average height of the surface hairiness could be determined (marked with a red line, Fig. 1d). 243 condition under which it was conditioned. 2.2 Fabric surface hairiness The height of the surface hairiness of the fabric, expressed in millimeters, was determined for each prepared 29–30 May 2025, Ljubljana, Slovenia specimen using the digital image of the surface (Fig. 1c) taken with the camera of the digital microscope. The digital image of the specimen surface had to be converted to black and white image so that the average height of the surface hairiness could be determined (marked with a red line, Fig. 1d). a) b) c) d) Figure 1: Figure 1: Dino-Lite AM - 4113ZT digital microscope a), Dino-Lite calibration measurement tool b), digital image of the cotton Dino-Lite AM - 4113ZT digital microscope a), Dino-Lite calibration measurement tool b), digital image of the cotton fabric surface (5.7x), with added measuring scale c), and it black and white image d) fabric surface (5.7x), with added measuring scale c), and it black and white image d) During image acquisition, the specimen was placed on specimen holders used for modified Martindale method, During image acquisition, the specimen was placed on specimen holders used for modified Martindale method, and therefore they were supported by felt. The device used for image acquisition was the Dino-Lite AM - and therefore they were supported by felt. The device used for image acquisition was the Dino-Lite AM - 4113ZT digital microscope (Fig. 1a), which was positioned at the height of the specimen surface at a distance of 26 cm from the edge of the specimen holder, with a magnification of 5.7x. During image acquisition, the specimens were 2 placed in a darkened room and their surface was illuminated with a light source with artificial daylight D65 at an angle 15° to the plane of the specimen surface. The Dino-Lite calibration measuring tool (Fig. 1b) was used to create a measuring scale (Fig. 1c, d) to determine the average height of the surface hairiness. The mean value (H ) from the determined height of the surface hairiness layer of the three specimens for each fabric, was used as sl the result for the atmospheric condition under which they were conditioned. 2.3 Fabric electrical resistance The measurement of surface resistivity (r) and vertical resistance (R) was carried out according to the European standard methods EN 1149-1 and -2 by using the conductivity tester, Static Lab 291B (Fig. 2), which is equipped with circular electrode, specimen holder and isolating plate. When the specimen is placed on the specimen holder with the insulating plate, the surface resistivity is measured and when the specimen is placed on the specimen holder without the insulating plate, the vertical resistance is measured. Figure 2: Conductivity tester - Static Lab 291B Mesdan S.p.A., Italy 244 29–30 May 2025, Ljubljana, Slovenia According to the standard methods for the measurement of textile materials electrical resistance values, the tes Figure 2: Conductivity tester - Static Lab 291B Mesdan S.p.A., Italy -ted specimens should be conditioned in an atmosphere with a temperature of 23 ± 1 °C and a relative humidity of 25 ± 5 % According to the standard methods for the measurement of textile materials electrical resistance values, the (AC1) before testing. However, since the aim of this study is to assess the influence of fabric surface hairiness on it electrical resistance, the measurements of the fabrics electrical resistances were performed on tested specimens should be conditioned in an atmosphere with a temperature of 23 ± 1 °C and a relative specimens conditioned under different atmospheric conditions. Three additional atmospheric conditions were humidity of 25 ± 5 % (AC1) before testing. However, since the aim of this study is to assess the influence of selected and one of these corresponded to the standard atmosphere for conditioning and testing of textiles (EN fabric surface hairiness on it electrical resistance, the measurements of the fabrics electrical resistances were ISO 139:2005/A1:2011), which is generally used for textile testing, with a temperature of 20 ± 2 °C and a relative performed on specimens conditioned under different atmospheric conditions. Three additional atmospheric rature of 20 ± 2 °C, but in a lower and higher range of relative humidity of 40 ± 5 % (AC2) and 80 ± 5 % (AC4). testing of textiles (EN ISO 139:2005/A1:2011), which is generally used for textile testing, with a temperature of 20 ± 2 °C and a relative humidity of 65 ± 4 % (AC3). The other two conditions were then interpolated around humidity of 65 ± 4 % (AC3). The other two conditions were then interpolated around these values, with a tempe conditions were selected and one of these corresponded to the standard atmosphere for conditioning and - these values, with a temperature of 20 ± 2 °C, but in a lower and higher range of relative humidity of 40 ± 5 % (AC2) and 80 ± 5 % (AC4). 2.4 Fabric residual electrical resistance The influence of surface hairiness on the electrical resistance of the fabric was investigated by analyzing the 2.4 Fabric residual electrical resistance measured resistances, or more precisely fabrics residual electrical resistances and the determined height of The influence of surface hairiness on the electrical resistance of the fabric was investigated by analyzing the the surface hairiness layer. The residual electrical resistance is an additional factor, expressed as a percentage, measured resistances, or more precisely fabrics residual electrical resistances and the determined height of which represents the ratio between the resistances measured under atmospheric conditions with higher relative the surface hairiness layer. The residual electrical resistance is an additional factor, expressed as a humidity (AC2, AC3 or AC4) and the one with the lowest relative humidity AC1.The residual electrical resistances percentage, which represents the ratio between the resistances measured under atmospheric conditions with 1) and vertical resistance ( electrical resistances are calculated separately according to equations 1 and 2 for measured values of surface R , Eq. 2). R40,65,80 resistivity ( are calculated separately according to equations 1 and 2 for measured values of surface resistivity ( higher relative humidity (AC2, AC3 or AC4) and the one with the lowest relative humidity AC1.The residual R , Eq. r40,65,80 Rr40,65,80, Eq. 1) and vertical resistance (RR40,65,80, Eq. 2). 𝑅𝑅𝑅𝑅 𝑟𝑟𝑟𝑟 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴2 , 𝑟𝑟𝑟𝑟 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴3, 𝑟𝑟𝑟𝑟 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴4 𝑅𝑅𝑅𝑅 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴2, 𝑅𝑅𝑅𝑅𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴3, 𝑅𝑅𝑅𝑅 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴4 𝑟𝑟𝑟𝑟40 , 65 , 80 = ∙ 100 , 𝑅𝑅𝑅𝑅 𝑅𝑅𝑅𝑅40 , 65 , 80 = ∙ 100 (1,2) 𝑟𝑟𝑟𝑟 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴1 𝑅𝑅𝑅𝑅 𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴1 3. RESULTS WITH DISCUSSION 3 At the beginning of this study, the basic physical properties of the fabric were determined under a standard atmo-sphere for textile testing (AC2). The results (Tab. 1) show that the viscose fabrics has the highest value for mass per unit area, while the polyamide 6.6 fabric has the highest value for thickness. Table 1: Fabrics physical properties determined under standard atmosphere for testing (AC2) Fabric physical properties Cotton Viscose Polyester Polyamide 6.6 Mass per unit area [g/m2] 114.4 141.6 134.2 131.4 Thickness [mm] 0.28 0.26 0.26 0.33 245 29–30 May 2025, Ljubljana, Slovenia Table 2: Mean values of mass, moisture content, thickness and height of surface hairiness layer (H ) of the sl three specimens of the same fabric after conditioning under different atmospheric conditions (AC1-AC4) Fabric Mass of specimen [g] Moisture content [%] Thickness [mm] H [mm] sl AC1 1.648 1.978 0.28 1.22 AC2 1.674 3.627 0.28 1.31 Cotton AC3 1.717 6.282 0.28 1.42 AC4 1.739 7.659 0.28 1.64 AC1 1.961 3.468 0.26 1.93 AC2 1.983 4.615 0.26 2.16 Viscose AC3 2.103 10.940 0.26 2.30 AC4 2.159 13.907 0.26 2.57 AC1 2.007 0.117 0.26 0.23 AC2 2.010 0.261 0.26 0.24 Polyester AC3 2.012 0.359 0.26 0.24 AC4 2.013 0.408 0.26 0.24 AC1 1.966 0.924 0.33 1.24 AC2 1.983 1.800 0.33 1.30 Polyamide 6.6 AC3 2.019 3.660 0.33 1.31 AC4 2.040 4.715 0.33 1.35 As there are many factors that can influence the electrical resistance value of fabrics, the values for mass, mo-isture content, thickness and height of surface hairiness layer where determined for each specimen during the test. The average values of three specimens of the same fabrics for every atmospheric condition under they were conditioned are shown in Table 2. The mass of the specimen changed depending on the amount of moisture absorbed under different atmospheric conditions, while the value of the fabrics thickness has not changed. The height of the surface hairiness layer (H ) of the specimens increased slightly under atmospheric conditions with sl higher relative humidity. Table 3: Results of surface resistivity (r) and vertical resistance (R) measured at different atmospheric condi-tions Electrical resistance Cotton Viscose Polyester Polyamide 6.6 AC1 57.800 × 1012 49.667 × 1012 81.200 × 1012 43.00 × 1012 r [Ω] 12 AC2 3.217 × 1012 11.390 × 1012 31.567 × 1012 35.467 × 1012 AC3 0.028 × 10 0.042 × 1012 28.000 × 1012 16.260 × 1012 AC4 0.003 × 1012 0.003 × 1012 21.420 × 1012 3.275 × 1012 AC1 29.640 × 109 475.200 × 109 227.400 × 109 497.400 × 109 R [Ω] 9 AC2 4.857 × 109 69.425 × 109 76.862 × 109 360.000 × 109 AC3 0.084 × 10 0.166 × 109 2.747 × 109 18.100 × 109 AC4 0.005 × 109 0.007 × 109 1.204 × 109 3.197 × 109 The measured values for surface resistivity and vertical resistance listed in Table 3 show a decrease in the values when the specimens were conditioned under atmospheric conditions with higher relative humidity. This decrease is more pronounced for cotton and viscose fabrics than for polyester and polyamide 6.6 fabrics. 246 29–30 May 2025, Ljubljana, Slovenia The measured values for surface resistivity and vertical resistance listed in Table 3 show a decrease in the values when the specimens were conditioned under atmospheric conditions with higher relative humidity. This decrease is more pronounced for cotton and viscose fabrics than for polyester and polyamide 6.6 fabrics. a) b) c) d) Figure 3: Graphical representation of height of surface hairiness layer and the calculated residual surface resistivity (a, b) resistivity (a, b) and vertical resistance (c, d) values Figure 3: Graphical representation of height of surface hairiness layer and the calculated residual surface and vertical resistance (c, d) values one for the cotton and viscose fabric and the other for the polyester and polyamide 6.6 fabric, as there is a large R ) are r40,65,80 shown in Figures 3 a and b, and the results of the calculated residual vertical resistance ( R R40,65,80 ) are shown difference between their values. The results of the calculated residual surface resistivity ( R ) are shown in in Figures 3 c and d. In all diagrams, these values are compared with the average height of surface hairiness r40,65,80 Figures 3 a and b, and the results of the calculated residual vertical resistance ( R ) are shown in Figures 3 layer ( When analyzing the results of the individual residual electrical resistances, fabrics are divided into two groups, one for the cotton and viscose fabric and the other for the polyester and polyamide 6.6 fabric, as there is a large difference between their values. The results of the calculated residual surface resistivity ( When analyzing the results of the individual residual electrical resistances, fabrics are divided into two groups, c and d. In all diagrams, these values are compared with the average height of surface hairiness layer (), which is ���� 𝐻𝐻𝐻𝐻), which is calculated from the mean values determined under AC1-AC4 conditions (Tab. 2). R40,65,80 𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠 calculated from the mean values determined under AC1-AC4 conditions (Tab. 2). From this perspective, it can be seen that the values of the residual electrical resistances for each fabric sample From this perspective, it can be seen that the values of the residual electrical resistances for each fabric sample conditioned. Furthermore, when analyzing the values of residual surface resistivity (Figs. 3a, b), it can be seen decrease with the increase in the relative humidity of the atmospheric conditions under which they were decrease with the increase in the relative humidity of the atmospheric conditions under which they were condi-that they correlate with the average height of surface hairiness, which means that a lower height of surface tioned. Furthermore, when analyzing the values of residual surface resistivity (Figs. 3a, b), it can be seen that hairiness layer leads to lower values of the fabric's residual surface resistivity. The values of residual vertical they correlate with the average height of surface hairiness, which means that a lower height of surface hairiness resistance for polyester and polyamide 6.6 fabrics (Fig. 3d) show the same correlation with the average height layer leads to lower values of the fabric‘s residual surface resistivity. The values of residual vertical resistance for of the surface hairiness layer as the values of their surface resistivity. This is not the case for cotton and viscose polyester and polyamide 6.6 fabrics (Fig. 3d) show the same correlation with the average height of the surface fabrics. The reason for that can be assigned to fabric structure (Tab. 1) and the moisture content (Tab. 2), hairiness layer as the values of their surface resistivity. This is not the case for cotton and viscose fabrics. The which has a major influence on the electrical resistance of the fabric (Tab. 3). reason for that can be assigned to fabric structure (Tab. 1) and the moisture content (Tab. 2), which has a major influence on the electrical resistance of the fabric (Tab. 3). 5 247 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS From the conducted research, it can be seen that the introduced residual electrical resistance value captures the influence of fabrics surface hairiness layer on its electrical resistance values. The influence can be seen in the residual surface resistivity values of the fabric, whereby the fabrics with a higher surface hairiness have a higher residual surface resistivity value. The electrical resistance values still depend strongly on the fiber composition and the atmospheric conditions (relative humidity) under which the fabric is conditioned. Therefore, the influence of the fabrics surface hairiness layer on its electrical resistance should not be conducted under atmospheric con-ditions with very high relative humidity (AC4). 5. REFERENCES Abo-Basha, S.S., Nassar, K.M. and Mohamed, R.A. 2024. “Antistatic Textiles: Current Status and Future Outlook.” Journal of Art, Design and Music 3 (2): 236–50. Asanovic, K.A., Cerovic, D.D., Kostic, M.M., Maletic, S.B. and Ivanovska, A.M. 2022. “Electro-Physical Properties of Woven Clothing Fabrics Before and After Abrasion.” Journal of Natural Fibers 19 (4): 1–12. Hałgas, S., Wilbik-Hałgas, B. and Sidyk, P. 2024. “Modeling and Testing of ESD Protective Textiles.” Applied Sciences (Switzerland) 14 (16): 1–24. Hong, H., Hu, J. and Yan X. 2020. “Effect of the Basic Surface Properties of Woven Lining Fabric on Printing Precision and Electrical Performance of Screen-Printed Conductive Lines.” Textile Research Journal 90 (11–12): 1212–23. Kim, W. G., Kim, D. W., Tcho, Il-W., Kim, J.-K., Kim, M.-S. and Choi, Y.-K. 2021. “Triboelectric Nanogenerator: Structure, Mechanism, and Applications.” ACS Nano 15 (1): 258–87. Nurmi, S., Hammi, T. and Demoulin B. 2007. “Protection Against Electrostatic and Electromagnetic Phenomena.” Springer Series in Materials Science 97: 63–83. Paasi, J., Coletti, G., Fast, L., Lemaire, P. and Vogel, C. 2002. “ESD-Protective Clothing for Electronics Industry – A New European Research Project ESTAT-Garments.” Solutions 1 (8): 2–9. Paasi, J., Fast, L., Kalliohaka, T., Smallwood, J., Börjesson, A., Haase, J., Vogel, C. et al. 2005. “Risks of Damage to Electronics with Reference to Charged Clothing.” Journal of Electrostatics 63 (6–10): 603–8. Salvado, R., Loss, C., Gonçalves, R. and Pinho, P. 2012. “Textile Materials for the Design of Wearable Antennas: A Survey.” Sensors (Switzerland) 12 (11): 15841-15857. Sereda, P.J. and Feldman R.F. 1964. “Electrostatic Charging on Fabrics at Various Humidities.” Journal of the Textile Institute Transactions 55 (5): T288–98. Varnaite-Žuravliova, S., Stygiene, L., Čepliauskiene, R., Krauledas, S. and Sankauskaite, A. 2013. “The Influence of Three-Layer Knitted Fabrics’ Structure on Electrostatic and Comfort Properties.” Materials Science 19 (4): 415–19. Varnaite, S., and Katunskis, J. 2009. “Influence of Washing on the Electric Charge Decay of Fabrics with Conductive Yarns.” Fibres and Textiles in Eastern Europe 76 (5): 69–75. Welker, R.W., Nagarajan, R. and Newberg, C.E. 2005. “Fundamentals of ESD Control.” In Contamination and ESD Control in High₂ Technology Manufacturing, 48–118. New Jersey: John Wiley & Sons, Inc., Hoboken. Zhu, R., Zhang, P. and Nie, F. 2013. “Overview and Correlation Study on Electrostatic Property of Different Testing Standards.” In Advanced Materials Research 627:325–28. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Juro Živičnjak Antoneta Tomljenović Faculty of Textile Technology Faculty of Textile Technology Department of Materials, Department of Materials, University of Zagreb University of Zagreb Fibers and Textile Testing Fibers and Textile Testing Prilaz baruna Filipovića 28a Prilaz baruna Filipovića 28a 10000 Zagreb Croatia 10000 Zagreb Croatia +385 1 3712 522 antoneta.tomljenovic@ttf.unizg.hr +385 1 3712 524 juro.zivicnjak@ttf.unizg.hr 248 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION COMPARISON OF ABSORBENCY PROPPERTIES OF DISPOSABLE AND REUSABLE SANITARY PADSTITLE OF THE PAPER Blažka Kumer1 and Živa Zupin1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Sanitary pads are hygiene products that belong to the medical textiles, which are categorised as techni-cal textiles. Both disposable and reusable sanitary pads can be found on the market, whereby disposable sanitary pads represent a large amount of poorly degradable waste, while reusable sanitary pads are more environmental-ly friendly. The study compared the absorption properties of disposable and reusable sanitary pads. Five different disposable sanitary pads, which are the most commonly used in Slovenia, and one type of reusable sanitary pads were used. In terms of comfort and absorption properties such as fluid absorption and retention, moisturising sen-sation and capillary rise, disposable sanitary pads have significantly better properties as they usually contain SAP and are comfortable for the user. Reusable sanitary pads are more environmentally friendly but less comfortable, as our study also confirms. Keywords: reusable and disposable sanitary pads, absorption properties, absorption rate, wetting, moisturising sensation. 1. INTRODUCTION Sanitary pads are hygiene products that belong to the medical textiles, which are categorised as technical textiles. There are disposable sanitary towels and reusable sanitary pads. In both cases, the choice of materials is import-ant in order to achieve the required mechanical, functional, comfortable, permeable and absorbent properties. At the same time, the materials must be safe for women’s health and preferably biodegradable. Several studies have shown that people living near landfills, where sanitary pads are commonly disposed of, have a higher risk of becoming ill. An increased risk of bladder cancer and leukaemia in women has been demonstrated. Other studies have shown malformations of the nervous system and musculoskeletal system (Zins 2011). According to calcula-tions based on market data and assumptions about census data, the amount of sanitary waste generated in the UK is around 28,114 tonnes per year. Sanitary towels are the most commonly used, accounting for around 21,049 tonnes of waste per year (Blair 2022). Disposable sanitary pads are mainly made from synthetic materials, namely polyethylene for the top layer and superabsorbent polymers for the middle absorbent layer. The bottom layer usually consists of a liquid-tight film to prevent leakage and is usually made of polyethylene. Reusable pads also consist of a top layer, a middle ab-sorbent core made of absorbent materials and a leak-proof layer of polyurethane laminate (PUL) at the bottom. The top layer is the absorbent layer and transports the liquid to the absorbent core underneath. The upper and absorbent middle layer consists of materials such as cotton, viscose, bamboo viscose or lyocell. The fabrics can be velour, fleece, jersey, terrycloth or flannel (Barman 2017). Researchers have been looking for suitable biodegradable materials that could replace conventional synthetic materials in disposable sanitary pads. It was found that lyocell fibres could replace polypropylene fibres. Organic cotton fibres could be used for the top layer, bamboo, jute, banana, rice and flax fibres as well as cellulose hydro-gel for the absorbent core and a bioplastic polymer PLA for the lower, impermeable layer (Barman 2017, Siddiqe 2019). It was found that most of the samples of the upper layer were made of polypropylene, which was composed of a nonwoven fabric using the spunbond technique with point bonding (Pohlmann 2016). Some researchers have also compared the properties of disposable and reusable sanitary pads. They investigated the skin irritation of 249 29–30 May 2025, Ljubljana, Slovenia disposable and reusable sanitary pads when wet and dry. They found that the friction force of disposable sanitary pads is lower than that of reusable sanitary pads, while the wettability of disposable sanitary pads with a non-wo-29–30 May 2025, Ljubljana, Slovenia ven surface is lower than that with a perforated surface. They also found that reusable sanitary towels absorb more moisture directly on the skin than disposable sanitary pads under the same load (Tang 2020, Tang 2019). 2. EXPERIMENTAL 2. EXPERIMENTAL In order to compare the absorption properties of disposable and reusable sanitary pads, five disposable sanitary In order to compare the absorption properties of disposable and reusable sanitary pads, five disposable pads (samples 1 to 5) and one reusable sanitary pad (sample 6) were used. The most commonly used brands of sanitary pads (samples 1 to 5) and one reusable sanitary pad (sample 6) were used. The most commonly used sanitary pads in Slovenia were used. Disposable sanitary pads ( sample 5) and reusable sanitary pads (sample 6) brands of sanitary pads in Slovenia were used. Disposable sanitary pads ( sample 5) and reusable sanitary were produced by two different Slovenian manufacturers. All sanitary pads are used for medium to heavy bleed pads (sample 6) were produced by two different Slovenian manufacturers. All sanitary pads are used for -ing. Table 1 shows the composition of the samples. medium to heavy bleeding. Table 1 shows the composition of the samples. All sanitary pads were analysed with the SEM (JSM-6060LV (JEOL – Japan) at 100x magnification, the All sanitary pads were analysed with the SEM (JSM-6060LV (JEOL – Japan) at 100x magnification, the composi composition of the tested sanitary pads were determinated with the FT-IR Spectrum 3 (Perkin Elmer, Great -tion of the tested sanitary pads were determinated with the FT-IR Spectrum 3 (Perkin Elmer, Great Britain). Britain). The following tests were performed to compare the absorption properties: absorption rate of the entire sanitary The following tests were performed to compare the absorption properties: absorption rate of the entire sanitary pad and individual layers, transferred liquid, which can give a sensation of moisture, drop test, wetting and cap-pad and individual layers, transferred liquid, which can give a sensation of moisture, drop test, wetting and illary rise. capillary rise. The absorption rate of the entire sanitary pad and the individual layers was tested using water with dispersed The absorption rate of the entire sanitary pad and the individual layers was tested using water with dispersed dye dripped onto the centre of the pad. The initial mass of the entire sanitary pad and the individual layers was dye dripped onto the centre of the pad. The initial mass of the entire sanitary pad and the individual layers was measured. 15 ml of liquid was dripped onto the pad and was allowed to absorb. The process was repeated until measured. 15 ml of liquid was dripped onto the pad and was allowed to absorb. The process was repeated the liquid began to spill over the edge. The pad was then weighed again. The absorption rate was calculated us-until the liquid began to spill over the edge. The pad was then weighed again. The absorption rate was ing equation 1. After testing the absorbency of the entire pad, the layers were separated and weighed again. The calculated using equation 1. After testing the absorbency of the entire pad, the layers were separated and absorption rate of the entire sanitary pad and individual layers was calculated using equation 1. weighed again. The absorption rate of the entire sanitary pad and individual layers was calculated using equation 1. 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑎𝑎𝑎𝑎 [𝑚𝑚𝑚𝑚𝑙𝑙𝑙𝑙] 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑟𝑟𝑟𝑟 = (𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚/min ) (1) 𝑡𝑡𝑡𝑡𝑙𝑙𝑙𝑙𝑚𝑚𝑚𝑚𝑎𝑎𝑎𝑎 [𝑚𝑚𝑚𝑚𝑙𝑙𝑙𝑙𝑚𝑚𝑚𝑚] The transferred liquid, which present a sensation of moisture feels moist, was tested with filter paper. 5 minutes The transferred liquid, which present a sensation of moisture feels moist, was tested with filter paper. 5 minutes after the last addition of liquid in the absorbency test, the previously weighed dry filter paper was placed on after the last addition of liquid in the absorbency test, the previously weighed dry filter paper was placed on the the sanitary pad and held there for 30 seconds. The filter paper was then removed and weighed immediately. sanitary pad and held there for 30 seconds. The filter paper was then removed and weighed immediately. If no If no liquid is transferred, the filter paper remains relatively dry. liquid is transferred, the filter paper remains relatively dry. The absorbency drop test was performed according to the AATCC test method 79 using a stamp and a dropper. First, the circles were stamped on each sanitary pad with a dot in the middle. A drop of coloured water was placed placed in the middle of the circle and the time taken for the drop to be completely absorbed by the material was measured. The absorbency drop test was performed according to the AATCC test method 79 using a stamp and a dropper. First, the circles were stamped on each sanitary pad with a dot in the middle. A drop of coloured water was in the middle of the circle and the time taken for the drop to be completely absorbed by the material was measured. Wetting was evaluated using the sinking test method based on the standard method EN 14697:2005 - Textiles Wetting was evaluated using the sinking test method based on the standard method EN 14697:2005 - Textiles - Terry towels and terry towel fabrics - Specification and methods of test, Annex B - Determination of the time - Terry towels and terry towel fabrics - Specification and methods of test, Annex B - Determination of the time of of absorption. The time required for a piece of fabric to sink completely out of the surface layer of water in a absorption. The time required for a piece of fabric to sink completely out of the surface layer of water in a beaker beaker was measured. For this purpose, a 3 × 3 cm piece was cut out of the fabric and placed on the surface was measured. For this purpose, a 3 × 3 cm piece was cut out of the fabric and placed on the surface layer of wa-layer of water in a 500 ml beaker. The wetting time was estimated with a stopwatch as the time interval between ter in a 500 ml beaker. The wetting time was estimated with a stopwatch as the time interval between the moment the moment of immersion and the moment when the sample had sunk below the water level. Each experiment of immersion and the moment when the sample had sunk below the water level. Each experiment was performed was performed at least three times (Pavko Čuden, 2010, Saville, 1999) at least three times (Pavko Čuden, 2010, Saville, 1999) Samples measuring 200 mm x 25 mm in the longitudinal direction were used to measure capillary rise. The Samples measuring 200 mm x 25 mm in the longitudinal direction were used to measure capillary rise. The sam-sample was rotated vertically and immersed in a beaker containing distilled water and dye (1% Prussian blue). ple was rotated vertically and immersed in a beaker containing distilled water and dye (1% Prussian blue). After a After a specified time (1 min, 2 min, 3 min, 4 min and 10 min), the height of the capillary rise of the water was specified time (1 min, 2 min, 3 min, 4 min and 10 min), the height of the capillary rise of the water was read. The read. The measurements were carried out in accordance with DIN 53924. measurements were carried out in accordance with DIN 53924. 3. RESULTS WITH DISCUSSION 3. In Table 1 the composition of the studied samples with corresponding SEM images is presented. RESULTS WITH DISCUSSION In Table 1 the composition of the studied samples with corresponding SEM images is presented. 250 29–30 May 2025, Ljubljana, Slovenia Table 1: Compositions of the studied sanitary pads. Sample Upper (surface) layer Middle layer Bottom layer 1 polypropilen spunbonded cellulose and SAP Polyethylene nonwoven fabrics 2 polypropilen spunbonded cellulose and SAP Polyethylene nonwoven fabrics 3 polypropilen spunbonded cellulose and SAP Polyethylene nonwoven fabrics 4 cotton spunbonded non- cellulose and SAP Polyethylene woven fabrics 5 cotton spunbonded non- cellulose and SAP beads Polyethylene woven fabrics 6 knitted single jearsy 95% knitted terry of 77 % bamboo knitted terry fabrics of 70% cotton cotton, 5% elastan viscose in 23 % polyester and 30% polyester with polyeth- ylene film 251 29–30 May 2025, Ljubljana, Slovenia The absorption rate results (Figure 1) show that some disposable sanitary pads have a higher absorption rate than reusable sanitary pads, while others have a lower absorption rate, depending on the structure and materials used in the upper and middle layers. Disposable pads have a more absorbent middle layer, while the top and bottom layers absorb very little liquid. In reusable pads, the middle and top layers absorb almost the same amount of liquid. From the results in Figure 1, it can be concluded that samples 3, 4, 5 and 6 have almost the same ab-sorption rate, although the composition of the sanitary pads is different. The middle layer has a major influence on 29–30 May 2025, Ljubljana, Slovenia the absorption rate. The most absorbent middle layer is found in disposable sanitary pads that have an absorbent core of cellulose fibres with added SAP beads (sample 5). The bamboo viscose terry, the middle layer in reusable pads (sample 6), does not absorb as much liquid, but the bottom layer of knitted cotton terry also absorbs as much almost as much liquid as the most absorbent middle layer. knitted cotton terry also absorbs as much liquid as the middle layer, except that it is protected by a film to liquid as the middle layer, except that it is protected by a film to prevent the pad from leaking. Together they absorb prevent the pad from leaking. Together they absorb almost as much liquid as the most absorbent middle layer. Figure 1 also shows that the top layer does not absorb much liquid in all the samples tested, as it serves as a Figure 1 also shows that the top layer does not absorb much liquid in all the samples tested, as it serves as a sible to prevent leakage at the sides. The bottom layer only absorbs a minimal amount of liquid as it is made of possible to prevent leakage at the sides. The bottom layer only absorbs a minimal amount of liquid as it is made of hydrophobic, impermeable materials that primarily prevent the liquid from running over the cartridge, collection container. It allows the liquid to pass through to the middle layer, which can absorb as much as pos collection container. It allows the liquid to pass through to the middle layer, which can absorb as much as - the reusable pads. except for the reusable pads. hydrophobic, impermeable materials that primarily prevent the liquid from running over the cartridge, except for When measuring the moisture sensation (wet feeling) of the surface, it was found that reusable sanitary pads When measuring the moisture sensation (wet feeling) of the surface, it was found that reusable sanitary pads transfer almost twice the amount of liquid to the filter paper compared to disposable sanitary pads (Figure 2). The transfer almost twice the amount of liquid to the filter paper compared to disposable sanitary pads (Figure 2). ml). The upper layer, which consists of polypropylene spunbond in samples 1 and 3 and cotton nonwoven in sam and 5 (0,44 ml). The upper layer, which consists of polypropylene spunbond in samples 1 and 3 and cotton -nonwoven in sample 5, has the greatest influence on the moisture perception. The absorption rate of the middle lowest transformation of liquid on the filtration paper was observed for samples 3 (0,03 ml), 1 (0,29 ml) and 5 (0,44 The lowest transformation of liquid on the filtration paper was observed for samples 3 (0,03 ml), 1 (0,29 ml) sanitary pad also had an influence on the moisture sensation, while these samples also absorbing the most liquid. layer and the entire sanitary pad also had an influence on the moisture sensation, while these samples also ple 5, has the greatest influence on the moisture perception. The absorption rate of the middle layer and the entire absorbing the most liquid. Figure 1: Absorbency of whole pad and individual Figure 2: Transferred liquid from sanitary pads to layers. filtration paper, represents a wet feeling. The results of the drop test and the wetting test show that the liquid is absorbed fastest by the disposable The results of the drop test and the wetting test show that the liquid is absorbed fastest by the disposable sanitary sanitary pad sample 5 (with a cotton surface and a middle layer of cellulose mixed with SAP beads), while the pad sample 5 (with a cotton surface and a middle layer of cellulose mixed with SAP beads), while the result of result of the reusable sanitary pads was in the middle of the field. The cotton layer absorbs the liquid the fastest the reusable sanitary pads was in the middle of the field. The cotton layer absorbs the liquid the fastest compared compared to the other upper layers. The liquid is absorbed most slowly by the disposable sanitary pad sample to the other upper layers. The liquid is absorbed most slowly by the disposable sanitary pad sample 1 (with a 1 (with a polypropylene surface and a middle layer of cellulose and SAP). The top layer of sample 1 does not polypropylene surface and a middle layer of cellulose and SAP). The top layer of sample 1 does not allow rapid allow rapid absorption. absorption. Sample 5 was also the fastest to absorb the liquid completely in the wetting test (15.6 s), and the slowest sample 1 behaved in the same way as in the drop test. Sample 1 takes more than 2 hours to sink. The reason Sample 5 was also the fastest to absorb the liquid completely in the wetting test (15.6 s), and the slowest sample for this lies in the construction of the disposable sanitary pads. Sample 6, the reusable sanitary pad, takes 1 behaved in the same way as in the drop test. Sample 1 takes more than 2 hours to sink. The reason for this lies almost a minute to completely absorb the liquid and sink. Cotton and bamboo viscose fabrics in reusable in the construction of the disposable sanitary pads. Sample 6, the reusable sanitary pad, takes almost a minute sanitary pads cannot absorb as much liquid as the middle layer of disposable sanitary pads with incorporated to completely absorb the liquid and sink. Cotton and bamboo viscose fabrics in reusable sanitary pads cannot SAP. absorb as much liquid as the middle layer of disposable sanitary pads with incorporated SAP. 252 1 (with a polypropylene surface and a middle layer of cellulose and SAP). The top layer of sample 1 does not allow rapid absorption. Sample 5 was also the fastest to absorb the liquid completely in the wetting test (15.6 s), and the slowest sample 1 behaved in the same way as in the drop test. Sample 1 takes more than 2 hours to sink. The reason 29–30 May 2025, Ljubljana, Slovenia for this lies in the construction of the disposable sanitary pads. Sample 6, the reusable sanitary pad, takes almost a minute to completely absorb the liquid and sink. Cotton and bamboo viscose fabrics in reusable sanitary pads cannot absorb as much liquid as the middle layer of disposable sanitary pads with incorporated SAP. Figure 3: Absorbency time in drop test. Figure 4: Time of total absorbency in wetting test. Figure 3: Absorbency time in drop test. Figure 4: Time of total absorbency in wetting test. The capillary rise test shows that disposable sanitary pads are vertically more absorbent than reusable sanitary 4 pads, which achieve the worst result. The capillarity test shows that after 10 minutes the best result is achieved with sample 2, which has absorbed the liquid along its length (18 cm). The second best absorption is observed with sample 5. As Figure 5 shows, there is no major difference in capillary rise between the disposable sanitary pads tested. The lowest result in the capillary rise test was achieved by the reusable sanitary pads (sample 6), as can be seen in Figure 5. As with wetting, the speed of capillary rise is also influenced by the hydrophilicity of the fibres and the distance between them. The more hydrophilic the fibres are and the more space they have, the faster they become wet and swell. Figure 5: Capillary rise of a sanitary pad. 4. CONCLUSIONS In terms of comfort and absorbency properties such as liquid absorption and retention, moisturising sensation and capillary rise, disposable sanitary pads have much better properties as they usually contain SAP. The best properties are achieved by sanitary pads that contain a high proportion of natural materials in their com-position and thus achieve good absorption properties. According to the research results, the best performance was observed in sample 5, adisposable sanitary pads from the Slovenian manufacturer. They are highly absor-bent and have an excellent ability to retain a large amount of liquid. They provide a medium feeling of dryness. The disposable pads in samples 3 and 4 have good absorbency and good liquid retention capacity. The sanitary pads in sample 3 provide a dry feeling, while the pads in sample 4 provide a rather moist feeling on the surface during use. Disposable pads of sample 1 absorb liquid poorly, but give a fairly good feeling of dryness. Disposable pads of sample 2 are fairly absorbent and provide a medium feeling of dryness. The reusable sanitary pads test-ed are well absorbent but give a moisturizing feeling on the surface. Disposable pads are simply convenient and popular, as the reusable pads produced to date do not achieve the same comfort properties. The use of reusable pads could increase with improvements in the materials used and thus improved comfort properties. 253 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Barman, A., Katkar, P. M., Asageker, S. D. 2017. “Natural and Sustainable Raw Materials for Sanitary Napkin”. Journal of Textile Science & Engineering 7(4): 1–3. Blair, L. A. G., Bajon–Fernandez, Y. and Villa, R. 2022. “An exploratory study of the impact and potential of menstrual hygiene management waste in the UK”. Cleaner Engineering and Technology 7: 1–7. Pavko Čuden, A., Stanković Elesini, U. 2010. “Elastane Addition Impact on Structural and Transfer Properties of Viscose and Polyacrylonitrile Knits”. Acta Chimica Slovenica 57(4): 957–962. Pohlmann, M. 2016. “Design and Materials Selection: analysis of similar sanitary pads for daily use”. International Journal of Engineering Research and Application 6(11): 74-79. Saville, B.P. 1999. “Physical testing of textiles”. Cambridge: Woodhead publishing, p.235. Siddiqe, R. 2019. “Sustainable alternatives for producing biodegradable Sanitary Napkins”. Bioresearch Communications 5(2): 737–743. Tang, K. M., Li, C. H., Kan, C. W. 2019. “Measurement of Liquid Transport Properties of Sanitary Napkin with Modified Forced Flow Water Transport Tester”. Fibers and Polymers 20(12): 2646–2653. Tang, K. M., Li, C. H., Kan, C. W. 2020. “Instrumentation for Measuring the Wet Frictional Property of Sanitary Pads”. Fibers and Polymers 21(1): 216–223. Zins, H. M. 2011. “Reusable medical textiles”. In Handbook of medical textiles, edited by V. T. Bartels, 80–105. Philadelphia: Woodhead Publishing Limited. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Živa Zupin Blažka Kumer Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering University of Ljubljana, University of Ljubljana, Department of Textiles, Department of Textiles, Graphic Arts and Design Chair of Textile and Graphic Arts and Design Chair of Textile and Clothing Engineering Clothing Engineering Aškerčeva 12 Aškerčeva 12 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia blazka.kumer@gmail.com +386 1 200 23 00 ziva.zupin@ntf.uni-lj.si 254 TEXTILE AND CLOTHING DESIGN 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION SUSTAINABLE PRACTICES IN SLOVENIAN FASHION LANDSCAPE Tanja Devetak1 1Centre for Design Research, Slovenia Abstract: The data collected in the research is related to sustainable practices in Slovenian fashion. The resear-ch included the mapping of the contemporary Slovene fashion brands as well as examples of Slovenian clothing industry that used some sustainable approaches. The activities included are zero-waste or less-waste design, recycling and up-cycling, the focus on the design and production of products that adapt and improve over the years, consumer participation in the design process, use of social media and the development of fashion commu-nities by fashion brands themselves. The review also includes services with product life-long repairs, the data on technological or production innovations, data on the local and/or regional supply and production chain as well as technological or production innovations implemented. In the need to reduce the fashion loop size, we reviewed the situation regarding the existence of ideas that contribute to less production and dematerialization. Keywords: Slovenian fashion, sustainable fashion, cultural diversity, handcraft tecniques. 1. INTRODUCTION The most emphasized segments in sustainable fashion design are the basic life cycle of the garment (production, use, and end of use) and the cultural and social aspects of fashion design (prevalence and nature of consumer-ism, participation of the user and the local environment, speed of the production and delivery). The involvement of the user or the community in the entire process is crucial and necessary; the fashion system transmits messages from the outside world to objects - clothes, while the user’s rituals (ritual of sale, ritual of maintenance, ritual of possession) enable the transmission of meanings from the object to the user (McCracken, 1986). Throughout the entire life cycle of clothing, the elements of social responsibility, economic profitability and protection of the natural and cultural environment should be taken into account and must be clearly reflected in the visualization of the product as well as in the conveyed meaning. Over the past fifty years, Slovenian fashion has demonstrated various approaches to sustainable fashion de-velopment, many times unplanned, but as positive reminders that the Slovenian fashion landscape instinctively perceived steps in the right direction of development, but was unable to capitalize them on the market. In the past, Slovenian clothing industry used some sustainable approaches, the realization of which was the result of econo-mic reasons and social circumstances. In contemporary Slovenian fashion, there are several different examples of the implementation of sustainable processes, which in many cases are not highlighted enough by brands as such. The first step within the research included overview of the fashion practices in the past, brands in the Slo-venian clothing industry which mostly no longer exist, but according to the data obtained, they included various sustainable practices in the past. The next step within the research included the mapping of the contemporary Slovene fashion brands which in-cludes the definition of fashion practices (scale and specialization) and the legal forms of businesses e.g. inde-pendent designers, private sector, NGO’s, cooperatives and initiatives. The criteria according to which they were selected were that they have been operating for several years in a row, over years successively design regular collections and they are present online (websites, Instagram or Facebook). The activities we considered in the research analysis included zero-waste or less-waste design, recycling and up-cycling, the focus on the design and production of products that adapt and improve over the years, consumer participation in the design process, use of social media (as a tool to educate about sustainable fashion as well to share brand stories) and the develop- 256 29–30 May 2025, Ljubljana, Slovenia ment of fashion communities by fashion brands themselves. The review also includes services with product life-long repairs as one of the options to slow the fashion consumption. In reducing the impact of the fashion industry on the environment, it is important to reduce energy and water consumption. Thus, in the further analysis of the selected mapped contemporary fashion brands, the data on technological or production innovations that require minimal energy and water consumption (e.g. clothes that require minimal cleaning, technical coatings to reduce washing, innovative and informative clothing labelling) were collected, where there were accessible. In addition, data on the local and/or regional supply and production chain were reviewed as well as technological or produc-tion innovations implemented. In the need to reduce the fashion loop size, we reviewed the situation regarding the existence of ideas that contribute to less production and dematerialization. This strategy introduces service concepts such as leasing, sharing and repair services that support the existing products. It is necessary to em-phasize the importance of the use of digital media tools of communication, which enable all the interested users’ traceability and transparency of the entire design and production process. In the context of sustainable fashion, we consider this as one of the key factors, as it also enables the democratization of information within fashion industry. With these communication channels, fashion can become better connected with its users, while at the same time using them as a tool to spread positive activist messages about the importance of sustainable fashion (Fletcher and Grose, 2011). Sustainable fashion design must also respect the cultural and historical specifics of ceratin geographical areas. Therefore, we include in the analysis the integration of handicraft techniques in fash-ion design as one of the central activities in the framework of sustainable and durable fashion, taking into account the meaning of preserving cultural heritage, as well as the promotion of do-it-yourself activities. In the research, the descriptive method was used as well as numerical evaluation, where the data collected allows it. 2. EXPERIMENTAL (MATERIALS AND METHODS) The research is focused on different sustainable solutions and practices implemented in Slovenian fashion land-scape. Methodologies used were based on qualitative and quantitative analysis of the gathered data, collected through reviews of official statistics and data, archives, interviews, and questionnaires. According to the Statista. com survey for 2021 in terms of revenue in the fashion industry Slovenia is ranking 76th globally. In addition, it also does not have a high symbolic value in terms of fashion recognition. Therefore, in the research, we wanted to find out wheter Slovenian fashion has an opportunity to form a sustainable national identity, given the sustainable activities that have been and are still being carried out by Slovenian fashion brands. In determining the criteria for research, the following fashion segments were included, which will have to be ad-ressed in the future, namely (Fletcher and Grose, 2012): - Products (materials, processes, distribution, maintenance of the products and their disposal); - Fashion system (speed, costumer’s needs, inclusion of customers, services of sharing/renting, local pro- duction and supply chain, life cycle optimization); - Design practices (communicator/educator, facilitator, activist and entrepreneur). The first step included the mapping of the fashion practices which includes the definition of fashion practices (sca-le, infrastructure and specialization e.g. sport wear, men wear, women wear, luxury) and the legal forms of busi-nesses e.g. independent designers, private sector, investors, fashion recycling projects, NGO’s, cooperatives and initiatives. In Slovenia, 45 brands were detected, most of them micro-scale businesses (more like one-man-b(r) and units). The criteria according to which they were selected were that they have been operating and designing for several years in a row, that they include fashion design process and successively design regular collections. The legal forms of businesses are very different: self-employed workers in culture, types of corporate structure or sole proprietors. They are geographically dispersed throughout the entire territory of Slovenia. Regarding the area of activity, fashion designers in Slovenia are mostly applying their skills in private sector, contrary to the requirements of sustainable fashion in which designers should be active across economic areas, e.g. public sec-tor, non-profit sector and research (Fletcher and Grose: 156). In the past, companies of Slovenian clothing industry were socially responsible, as today we would describe care for employees and the environment in which thay operated. In the period between 1945 and up to political and 257 29–30 May 2025, Ljubljana, Slovenia social changes, the clothing industry was specific, as the production space also developed into a potential social space (Bole, 2020). Employees in companies were connected to factories where they work, private life and their jobs were intertwined. The Slovenian clothing industry supported sport clubs, managed holiday homes, financed the construction of cultural institutions and the operation of cultural activities, supported firefighting associations etc. Company Industrija usnja Vrhnika (Vrhnika leather industry) purchased and systematically collected works 29–30 May 2025, Ljubljana, Slovenia of Slovenian art over the years of its existence. They took care of creating an atmosphere of trust and respect for employees and their well-being. The example of the company Modni salon Velenje (Fashion salon Velenje) is well known, in which, in order to prevent injuries and disabilities of production employees, they provided a break for recreation during work and for female workers over 40 years of age, the norm was abolished in favor of quality. Velenje (Fashion salon Velenje) is well known, in which, in order to prevent injuries and disabilities of production employees, they provided a break for recreation during work and for female workers over 40 years 3. of age, the norm was abolished in favor of quality. RESULTS WITH DISCUSSION The mapped business entities were then analyzed from the point of view of waste reduction, both in the produ- less-waste tailoring, recycling and upcycling, the focus on the design and production of products that adapt and The mapped business entities were then analyzed from the point of view of waste reduction, both in the production process and after the users discard it. The activities we considered in the analysis included zero-ction process and after the users discard it. The activities we considered in the analysis included zero-waste or RESULTS WITH DISCUSSION fashion brands themselves. The review also includes services with product life-long repairs as one of the options adapt and improve over the years (table 1), consumer participation in the design process, using social media (as a tool to educate about sustainable fashion as well to share brand stories) and the development of fashion to slow the fashion consumption and overcome the current clothing metabolism (Fletcher and Grose, 2012: 89). communities by fashion brands themselves. The review also includes services with product life-long repairs Due to the micro scale size of the brands in Slovenia, most of them have a service with product life-long repairs educate about sustainable fashion as well to share brand stories) and the development of fashion communities by waste or less-waste tailoring, recycling and upcycling, the focus on the design and production of products that improve over the years (table 1), consumer participation in the design process, using social media (as a tool to (87%) as well as consumer participation (80%). In this context, Slovenia has an advantage due to the size of the as one of the options to slow the fashion consumption and overcome the current clothing metabolism (Fletcher and Grose, 2012: 89). Due to the micro scale size of the brands in Slovenia, most of them have a service with businesses and should promote this as an important activity of sustainable fashion among users and as brand product life-long repairs (87%) as well as consumer participation (80%). In this context, Slovenia has an management. Slovenian fashion brands are less successful in including zero waste or less waste design (47%). advantage due to the size of the businesses and should promote this as an important activity of sustainable In the field of recycling, this is mainly present in knitting-based brands (42%) and in some cases in using textiles fashion among users and as brand management. Slovenian fashion brands are less successful in including made out of recycling material. zero waste or less waste design (47%). In the field of recycling, this is mainly present in knitting-based brands (42%) and in some cases in using textiles made out of recycling material. Table 1: Minimizing waste strategy Table 1: Minimizing waste strategy 100% 80% 60% 40% 20% 0% zero/less waste recycling upcycling consumer participation services of life-long repairs Thus, in the further analysis of the selected mapped fashion brands, the data on technological or production Thus, in the further analysis of the selected mapped fashion brands, the data on technological or production inno-innovations that require minimal energy and water consumption (e.g. clothes that require minimal cleaning, vations that require minimal energy and water consumption (e.g. clothes that require minimal cleaning, technical technical coatings to reduce washing, innovative and informative clothing labelling) as well as localization and coatings to reduce washing, innovative and informative clothing labelling) as well as localization and the use of the use of natural energy systems were collected. In addition, data on the local and/or regional supply and natural energy systems were collected. production chain were reviewed. In Slovenia, most brands use textiles that are not locally produced (only 9% In addition, data on the local and/or regional supply and production chain were reviewed. of them use locally produced textiles). Unlike clothing production, which is almost entirely local (96%). In Slovenia, most brands use textiles that are not locally produced (only 9% of them use locally The produced textiles). Unlike clothing production, which is almost entirely local (96%). need for self-sufficiency in the field of textile production was already discussed in the 1970s. At that time, The need for self-sufficiency in the field of textile production was already discussed in the 1970s. At that time, Slovenia was completely dependent Slovenia was completely dependent on the import of textiles from abroad or purchases in other former Yugoslav republics of the common country. They were aware of the strategic importance of self-sufficiency in textiles, so the strategic plans envisaged covering the needs for textiles until 1980 with a 34% share from own production and a 66% share that would still be imported. Technological or production innovations, which are key in reducing resources, are poorly represented in 258 Slovenian fashion brands (only a third of them use some elements of technological or production innovations within the clothing production and even then, innovations are not tied to reducing the energy consumption due to clothing maintenance). 29–30 May 2025, Ljubljana, Slovenia on the import of textiles from abroad or purchases in other former Yugoslav republics of the common country. They were aware of the strategic importance of self-sufficiency in textiles, so the strategic plans envisaged covering the needs for textiles until 1980 with a 34% share from own production and a 66% share that would still be imported. Technological or production innovations, which are key in reducing resources, are poorly represented in Slove-nian fashion brands (only a third of them use some elements of technological or production innovations within the 29–30 May 2025, Ljubljana, Slovenia clothing production and even then, innovations are not tied to reducing the energy consumption due to clothing maintenance). sharing and repair services that support the existing products. It also promotes multi-purpose products contribute to less production and dematerialization (table 2). This strategy introduces service concepts such (modular as leasing, sharing and repair services that support the existing products. It also promotes multi-purpose clothing). In this context, a transparent supply and production chain is extremely important, as is the formation of products (modular clothing). In this context, a transparent supply and production chain is extremely important, local/regional or online communities within these chains. It is necessary to emphasize the importance of the use bute to less production and dematerialization (table 2). This strategy introduces service concepts such as leasing, In the need to reduce the fashion loop size, we reviewed the situation regarding the existence of ideas that In the need to reduce the fashion loop size, we reviewed the situation regarding the existence of ideas that contri- as is the formation of local/regional or online communities within these chains. It is necessary to emphasize of digital media tools of communication, which enable all the interested users’ traceability and transparency of the the importance of the use of digital media tools of communication, which enable all the interested users’ entire design and production process. In the context of sustainable fashion, we consider this as one of the key traceability and transparency of the entire design and production process. In the context of sustainable fashion, factors, as it also enables the democratization of information within fashion industry. With these communication we consider this as one of the key factors, as it also enables the democratization of information within fashion channels, fashion can become better connected with its users, while at the same time using them as a tool to spre industry. With these communication channels, fashion can become better connected with its users, while at -ad positive activist messages about the importance of sustainable fashion. In Slovenia various services concepts the same time using them as a tool to spread positive activist messages about the importance of sustainable are not evenly developed. Forms of leasing or sharing are not developed enough (the resellers of wedding and fashion. In Slovenia various services concepts are not evenly developed. Forms of leasing or sharing are not formal dresses were not included in the analysis) in comparison to repairs which are implemented as their core developed enough (the resellers of wedding and formal dresses were not included in the analysis) in activities in almost three quarters of brands in Slovenia. They rarely use publicly verifiable data in their supply and comparison to repairs which are implemented as their core activities in almost three quarters of brands in production chain, therefore production transparency is very poor (31%). Digital communication channels are very Slovenia. They rarely use publicly verifiable data in their supply and production chain, therefore production poorly developed, so the data cannot even be widely available. transparency is very poor (31%). Digital communication channels are very poorly developed, so the data cannot even be widely available. Table 2: Table 2: Design for dematerialization and development of systems and services Design for dematerialization and development of systems and services 100% 80% 60% 40% 20% 0% leasing/shearing repair production transparency multi-purpose products There is the so-called There is the so-called fashion colonialism, within which the existence of local fashion specifics is not possible fashion colonialism , within which the existence of local fashion specifics is not possible or or allowed. Therefore, there is a ‘universal’ fashion that enforces the voluntary global uniformity of communities Sustainable fashion design must respect the cultural and historical specifics of individual geographical areas. Sustainable fashion design must respect the cultural and historical specifics of individual geographical areas. individuals and individuals. Decolonization of fashion means not only the actual geographical elimination of the dominance . Decolonization of fashion means not only the actual geographical elimination of the dominance of of fashion centres and their superiority, but also a change in the acceptance of one’s own fashion activity by allowed. Therefore, there is a ‘universal’ fashion that enforces the voluntary global uniformity of communities and munity in which fashion originates (Jansen, 2020). the community in which fashion originates (Jansen, 2020). We should not associate decolonization of fashion fashion centres and their superiority, but also a change in the acceptance of one’s own fashion activity by the com- image of confident fashion, which arises from the specifics of a particular geographical space in which fashion ori of a democratic image of confident fashion, which arises from the specifics of a particular geographical space -in which fashion originates and not only as copying universal fashion trends set by established fashion centres. ginates and not only as copying universal fashion trends set by established fashion centres. In developing a more In developing a more sustainable fashion industry, the integration of traditional handicraft techniques is crucial. sustainable fashion industry, the integration of traditional handicraft techniques is crucial. The latter are upgraded with the exploitation of the natural environment and labour force, but also with the establishment of a democratic exclusively with the exploitation of the natural environment and labour force, but also with the establishment We should not associate decolonization of fashion exclusively The latter are upgraded by designers with modern technological innovations. Creation of the products combines design and handicraft processes as a single indivisible whole. The importance of handicrafts is recognized as an important step in preserving the collective and individual cultural identity, while contributing The main handicraft techniques used by Slovenian fashion brands are knitting (13%), handmade screen to local production and waste reduction. 259 printing (13%) and less embroidery. When reviewing the fashion situation in Slovenia, we also took into account the analysis of the data related to labour rights and working conditions that are fair in case of Slovenian fashion. 29–30 May 2025, Ljubljana, Slovenia by designers with modern technological innovations. Creation of the products combines design and handicraft processes as a single indivisible whole. The importance of handicrafts is recognized as an important step in pre-serving the collective and individual cultural identity, while contributing to local production and waste reduction. The main handicraft techniques used by Slovenian fashion brands are knitting (13%), handmade screen printing (13%) and less embroidery. When reviewing the fashion situation in Slovenia, we also took into account the ana-lysis of the data related to labour rights and working conditions that are fair in case of Slovenian fashion. A sustainable fashion approach also opens up different business forms and operations. Due to the nature of the evolution of the Slovenian fashion landscape, various approaches are known in modern times, which ensure a sustainable and responsible approach in the long term. The shirting platform, developed by Elena Fajt together with Lucija Jankovec in 2014, is a project of a new clothing metabolism of wardrobe sharing. The invited design-ers each designed one shirt for themselves, which different users could ‘own’ for a certain period of time. They then passed it on to others for further use. The multifaceted project is an example of conceptual approaches in Slovenian fashion, which raises questions about the relevance of well-known and established business models in fashion, as well as connecting designers and users. With its attitude, the shirting platform is a pioneer in the Slovenian space in the context of creating fashion communities. The brand Things I Miss by designer Tina Princ connects interdisciplinary sustainable fashion practices with architecture, sound, movement and installations. The designer is actively involved in various global platforms – Fashion Revolution, Fashion Changers, Ethical Fashion Platform and others. Her clothes are also based on a conceptual connection with other creators with the aim of designing on the principle of zero waste. Vili Van Style was the pilot project of Julie Kaja Horvat. It was a boutique pop-up mobile store that operated from 2021 to 2023 with minor stops in between. It was intended to create a fashion community, a decentralized sales offer of Slovenian fashion and to connect young creators. Hish-ka is a brand of an interdisciplinary group led by Nataša Peršuh. It is based on three pillars: Re_Made, Re_Touch and Re_Vived. Sewist’s Appetite is Nastje Sagadin Grmek’s brand, which aims to involve users in the making of clothes by sharing the knowledge of complex cuts and finishing touches, encouraging individual creativity in the process of handmade clothes. 4. CONCLUSIONS The relationship between production and consumption plays a key role in the requirements for establishing ele-ments of a circular or regenerative economy. Technologically innovative production processes, respect for the rights of producers throughout the supply and production chain, thoughtful use of resources, and the inclusion of cultural diversity in individual geographical areas can be key in establishing a successful sustainable fashion con-text. Slovenian fashion has several examples of good sustainable practices, both in the past and today, and they can be guides for a successful breakthrough of Slovenian fashion on the global decolonized fashion landscape in the future. We believe that the data have shown that, due to many factors (especially economic and social), Slovenian fash-ion is able to formulate a sustainable fashion identity based on creativity and sophisticated fashion design, as a necessary foundation for modern long-term design solutions in the fashion landscape. Here, the advantage of Slovenian fashion lies in the fact that the majority of clothes are made with short production chains. Even more, most designers know the garment makers and are closely involved in the manufacturing process. The downside is that most of the manufacturing is outsourced. It is necessary to strengthen the local and regional supply and production chain. Given the micro-smallness of operating fashion brands, it is almost inevitable to connect in this area. Thus, Slovenian brands will have better production conditions, greater opportunities for presentations to other markets and, in general, greater recognition in the social environment in which they operate. Slovenia is very poorly developed in the production of natural fibers and textiles, which should be a priority in research and development. The opportunity lies in the establishment of a boutique made-to-order textile production. Due to their size, Slovenian fashion brands have the opportunity to enrich their communication activities with transparent information about production and supply chains and the introduction of open communication with users, all with the aim of forming fashion communities. Handcrafts are important but not widely implemented. In doing so, we can strengthen activities related to handcrafting, at the same time preserving the intangible cultural heritage with the aim of cultural diversity in the formation of a recognizable national fashion identity in the dominant fashion generic 260 29–30 May 2025, Ljubljana, Slovenia image. It is necessary to follow and strengthen innovative modern business forms that are adapted to the tradition and level of development of the Slovenian fashion landscape, and as such contribute even more to sustainable business forms of fashion. Cultural background defines the design of fashion products in order to get more diverse and sustainable fashion. We must proudly build a sustainable fashion future in Slovenian fashion landscape on the foundations that are already implemented, and strengthen the segments in which we are already lagging behind. So that it will not be necessary for some brands to hide their origins in order to succeed abroad, this is the way to jointly create results in the future within the framework of the sustainable fashion made in Slovenia brand. 5. REFERENCES Bole, P. 2020. “Muzealizacija Almire”. In Preteklost oblikuje sedanjost: Zbornik ob razstavi Alpska modna industrija Almira-Preteklost oblikuje sedanjost edited by Tanja Devetak, 21-31. Radovljica: Muzeji radovljiške občine. Carter, M. 2003. Fashion Classics: From Carlyle to Barthes. Oxford, New York: Berg. Fletcher, K., Grose, L. 2012. Fashion & Sustainability: design for change. London: Laurence King Publishing. Jansen, Angela 2020. Decolonizing Fashion: Defying the ‘White Man’s Gaze‘ http://vestoj.com/decolonialising-fashion/ (last accessed on 12. 11. 2020). Ladika, N. 1975. “Problematika tekstilne industrije.” Vezilo 11(12): 2. McCracken, G. 1986. “Culture and Consumption: a theoretical account of structure and movement of the cultural meaning of consumer goods.” Journal of Consumer Research 13(1):71-84. https://www.statista.com/outlook/244/141/fashion/italy (last accessed on 28. 2. 2021). The Fashion Praxis Collective 2014. The Fashion condition. New York, Gothenburg: The Fashion Praxis Collective/SelfPassage. Veblen, T. 2020. Teorija brezdelnega razreda: ekonomska študija institucij. Ljubljana: Znanstvena založba Filozofske fakultete. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Tanja Devetak Centre for Design Research Ul. Milana Majcna 35 1000 Ljubljana, Slovenia +38640470287 tanja.devetak@siol.net 261 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION FROM URBAN STREETS TO SANDY SHORES: EXPLORING THE “CITY TO BEACH” TREND IN FASHION Özgür Ceylan1, Emel Aydin1, Irmak Taş1, Nesligül Kiliç1, Neval Ergun2, 2 Aslihan Arpinar and Tuğçe Kaynak 2 1 Eskisehir Technical University, Turkey 2Mavi Giyim Sanayi ve Ticaret A.Ş., Turkey Abstract: The COVID-19 pandemic has significantly altered consumer behaviour, societal norms, and fashion industry strategies, emphasizing comfort, versatility, and sustainability. One emerging trend, “Bleisure,” merges business and leisure, influencing fashion choices that seamlessly transition between professional and casual set-tings. Post-pandemic work-life changes, including remote work and flexible schedules, have further reinforced the demand for adaptable clothing. This study examines these shifts through Mavi’s certain products, themed “City to Beach,” which highlight multi-contextual designs. The product group integrates natural fibres like cotton and linen for durability and thermal comfort, while innovative fabric blends enhance flexibility and style. Sustainable materials, minimalist aesthetics, and user-centric designs address evolving consumer expectations shaped by social media and pandemic-related needs. Findings indicate that lifestyle changes continue to reshape fashion preferences, urging brands to innovate sustainably. Mavi’s approach serves as a model for integrating style, func-tionality, and eco-consciousness, reflecting broader industry transformations in response to global challenges. Keywords: Bleisure, sustainable fashion, versatile design, post-pandemic trends, consumer adaptation. 1. INTRODUCTION The apparel industry exhibits a marked sensitivity to a confluence of social, economic, political, and psychological factors, alongside the impact of global events such as wars, pandemics, and technological advancements. The COVID-19 pandemic, originating in 2019 and significantly impacting global society, directly influenced individual and collective lifestyles. The post-pandemic period has witnessed substantial lifestyle shifts, notably a heightened interest in sustainable fashion consumption. These evolving patterns are driven by the intricate interplay of consumer resilience mechanisms, life aspirations, and approaches to sustainable consumption (Hwang et al., 2024). Concurrent studies indicate a growing consumer prioritization of comfort over adherence to fleeting trends, coupled with an increasing preference for sustainable fashion choices. Such behavioral changes necessitate adaptable marketing strategies aligned with these dynamic consumer demands (Ilijana & Jossan, 2024). Su and Bae (2022) underscore that these transformations have also intensified the focus on inclusivity and diversity in both consumer preferences and business strategies. Significantly, the transition towards remote work and flexible workspaces has reshaped clothing requirements and expectations, compelling the textile industry to adapt rapidly. These lifestyle adjustments, persisting even in the post-pandemic era, continue to exert influence on consumer demands and industry strategies (Karaca & Kozbekçi Ayranpinar, 2021).w Castells (2017) argues that spatial and societal transformations are mutually constitutive, emphasizing the reci-procal relationship between fashion design and evolving workplace dynamics. As workspaces become increasin-gly flexible, their influence on fashion design is inevitable. Social changes reshape physical spaces, and these spaces, in turn, influence the clothing preferences of the individuals inhabiting them. The pandemic significantly altered perceptions of living and working spaces. During this period, there was a no-table shift towards less densely populated, nature-integrated environments, with a corresponding decline in the appeal of traditional urban lifestyles (Tayanç, 2022). This trend coincided with a growing reliance on remote work models, adopted as a viable strategy for mitigating disease transmission risks (Dockery & Bawa, 2020). 262 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Business tourism, historically defined by work-related activities such as meetings, traditionally lacked a leisure, leisure, commonly termed „Bleisure“ (Betül & Ayyildiz, 2020; Çetinsöz & Hazarhun, 2020; Sood & Juneja, 2024). cultural, or recreational component. However, contemporary trends, particularly the increased flexibility offered by employers regarding work hours and locations, have transformed business travel into a hybrid of work and Bleisure travel enables professionals to integrate their work and personal lives, fostering a lifestyle that accommo-leisure, commonly termed "Bleisure" (Betül & Ayyıldız, 2020; Çetinsöz & Hazarhun, 2020; Sood & Juneja, dates both responsibilities and relaxation. While the pandemic significantly disrupted global tourism, leading to a by employers regarding work hours and locations, have transformed business travel into a hybrid of work and Business tourism, historically defined by work-related activities such as meetings, traditionally lacked a leisure, cultural, or recreational component. However, contemporary trends, particularly the increased flexibility offered This evolving travel dynamic underscores the importance of addressing consumer expectations and needs across leading to a substantial decline in tourism revenues, post-pandemic projections anticipate a recovery (Sood & diverse industries. Juneja, 2024). This evolving travel dynamic underscores the importance of addressing consumer expectations and needs across diverse industries. substantial decline in tourism revenues, post-pandemic projections anticipate a recovery (Sood & Juneja, 2024). accommodates both responsibilities and relaxation. While the pandemic significantly disrupted global tourism, 2024). Bleisure travel enables professionals to integrate their work and personal lives, fostering a lifestyle that As Bleisure travel increasingly becomes a lifestyle facilitated by flexible work arrangements, professionals can As Bleisure travel increasingly becomes a lifestyle facilitated by flexible work arrangements, professionals can extend this blended work-leisure approach into their daily lives. Clothing that offers adaptability across various extend this blended work-leisure approach into their daily lives. Clothing that offers adaptability across various contexts, ease of styling, and comfort has emerged as a paramount expectation within this lifestyle. The „City to contexts, ease of styling, and comfort has emerged as a paramount expectation within this lifestyle. The "City Beach“ theme, for instance, exemplifies this shift by emphasizing versatile, travel-friendly garments suitable for to Beach" theme, for instance, exemplifies this shift by emphasizing versatile, travel-friendly garments suitable seamless transitions between urban and leisure environments (WGSN, 2024). for seamless transitions between urban and leisure environments (WGSN, 2024). Figure 1. Figure 1. City to Beach Theme (WGSN, 2024) City to Beach Theme (WGSN, 2024) The pandemic also heightened awareness of sustainability, encouraging individuals to re-evaluate their con-The pandemic also heightened awareness of sustainability, encouraging individuals to re-evaluate their sumption habits and embrace sustainability as a core value. Sustainable consumption, which seeks to minimize consumption habits and embrace sustainability as a core value. Sustainable consumption, which seeks to negative environmental impacts while generating positive societal effects, aligns closely with this study‘s focus on minimize negative environmental impacts while generating positive societal effects, aligns closely with this reducing the need for separate work and vacation wardrobes and emphasizing garments with functional versatility study's focus on reducing the need for separate work and vacation wardrobes and emphasizing garments with and comfort (Halaçeli Metlioğlu & Yakin, 2021). functional versatility and comfort (Halaçeli Metlioğlu & Yakın, 2021). This study investigates the characteristics of products designed within the "City to Beach" theme and the This study investigates the characteristics of products designed within the „City to Beach“ theme and the Bleisu Bleisure concept, addressing user needs and expectations shaped by post-pandemic lifestyle changes. The -re concept, addressing user needs and expectations shaped by post-pandemic lifestyle changes. The research research examines the fashion industry's transformation in response to evolving societal dynamics, specifically examines the fashion industry‘s transformation in response to evolving societal dynamics, specifically focusing on focusing on the integration of work and vacation lifestyles into consumer clothing preferences. the integration of work and vacation lifestyles into consumer clothing preferences. 2. EXPERIMENTAL 2. EXPERIMENTAL The methodological approach employed is a qualitative case study, designed to provide an in-depth examination of a specific phenomenon within a real-world context. The primary aim of this case study is to The methodological approach employed is a qualitative case study, designed to provide an in-depth examination of offer a comprehensive analysis of the dynamics and interactions surrounding the phenomenon under a specific phenomenon within a real-world context. The primary aim of this case study is to offer a comprehensive investigation (Gerring, 2004). In this context, the case study serves not only as a research method but also as analysis of the dynamics and interactions surrounding the phenomenon under investigation (Gerring, 2004). In a strategic tool within the research process (Punch, 2005). this context, the case study serves not only as a research method but also as a strategic tool within the research process (Punch, 2005). This study evaluates Mavi, a globally recognized lifestyle fashion brand originating in Turkey, specifically focusing on its 2024 summer women's "City to Beach" woven and knit product lines. The analysis examines This study evaluates Mavi, a globally recognized lifestyle fashion brand originating in Turkey, specifically focusing how Mavi has achieved competitive advantage in the global market and adapted its design processes through on its 2024 summer women‘s „City to Beach“ woven and knit product lines. The analysis examines how Mavi has innovative approaches reflective of evolving societal dynamics. Furthermore, the research explores how these achieved competitive advantage in the global market and adapted its design processes through innovative appro-aches reflective of evolving societal dynamics. Furthermore, the research explores how these product groups have been shaped by global fashion trends and user demands, particularly concerning sustainability, comfort, 2 263 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia aesthetics, and functionality. The corresponding product groups are analysed not only from a design perspective but also to elucidate how the brand‘s consumer-focused strategies are integrated into its overall approach. product groups have been shaped by global fashion trends and user demands, particularly concerning 3. sustainability, comfort, aesthetics, and functionality. The corresponding product groups are analysed not only RESULTS WITH DISCUSSION from a design perspective but also to elucidate how the brand's consumer-focused strategies are integrated The findings of this study demonstrate how consumer expectations and needs within the apparel industry have into its overall approach. evolved, particularly in the post-pandemic period. The pandemic profoundly transformed individuals‘ lifestyles, work habits, and social interactions, leading to a significant reshaping of clothing preferences. The concept of 3. RESULTS WITH DISCUSSION reinforced by the rise of new work models, increased remote working opportunities, and growing awareness of evolved, particularly in the post-pandemic period. The pandemic profoundly transformed individuals' lifestyles, work habits, and social interactions, leading to a significant reshaping of clothing preferences. The concept of sustainability. Modern consumers are increasingly gravitating toward multi-functional, versatile clothing that se-Bleisure travel, which merges work and leisure, has played a crucial role in addressing these shifting demands. amlessly transitions between professional and casual environments. Key features such as stretchable fabrics, The necessity for garments that offer flexibility, comfort, and adaptability across diverse settings has been further The findings of this study demonstrate how consumer expectations and needs within the apparel industry have Bleisure travel, which merges work and leisure, has played a crucial role in addressing these shifting demands. breathability, and materials that ensure long-lasting comfort have become paramount in meeting these emerging The necessity for garments that offer flexibility, comfort, and adaptability across diverse settings has been further reinforced by the rise of new work models, increased remote working opportunities, and growing demands. awareness of sustainability. Modern consumers are increasingly gravitating toward multi-functional, versatile 3.1 Design Features stretchable fabrics, breathability, and materials that ensure long-lasting comfort have become paramount in meeting these emerging demands. clothing that seamlessly transitions between professional and casual environments. Key features such as Designs prioritizing versatile usage across different locations and contexts have gained prominence. These de-signs, emphasizing ease of styling, empower users to express their preferences across a wide range of appli 3.1 Design Features -cations while maintaining a sophisticated aesthetic without compromising comfort. Design elements inspired by coastal aesthetics introduce a refreshing and dynamic dimension to urban lifestyles, enhancing the overall user Designs prioritizing versatile usage across different locations and contexts have gained prominence. These experience. designs, emphasizing ease of styling, empower users to express their preferences across a wide range of applications while maintaining a sophisticated aesthetic without compromising comfort. Design elements inspired by coastal aesthetics introduce a refreshing and dynamic dimension to urban lifestyles, enhancing the A defining stylistic characteristic across product groups is an emphasis on elegance. In knitwear, adaptations for overall user experience. diverse locations are achieved through innovative pattern interpretations. The underlying concept facilitates se-amless transitions between daytime and evening wear and between urban and beach environments. This appro A defining stylistic characteristic across product groups is an emphasis on elegance. In knitwear, adaptations -ach aligns with sustainability considerations in fashion. A notable innovation is the use of knit fabrics with a woven for diverse locations are achieved through innovative pattern interpretations. The underlying concept facilitates appearance, providing a lightweight yet elegant solution that also prioritizes thermal comfort. seamless transitions between daytime and evening wear and between urban and beach environments. This approach aligns with sustainability considerations in fashion. A notable innovation is the use of knit fabrics with a woven appearance, providing a lightweight yet elegant solution that also prioritizes thermal comfort. For Mediterranean-themed product groups, the traditional evil eye talisman has been reinterpreted in terms of distinctive products. For the „Warm Mediterranean“ theme, the conventional colour palette has been expanded colour and form (Figure 2). The design process incorporates embroidery, printing, and accessory details to create distinctive products. For the "Warm Mediterranean" theme, the conventional colour palette has been colour and form (Figure 2). The design process incorporates embroidery, printing, and accessory details to create For Mediterranean-themed product groups, the traditional evil eye talisman has been reinterpreted in terms of tradition and innovation. expanded with mint green for the base and pale yellow tones in patterns, reflecting a forward-looking approach with mint green for the base and pale yellow tones in patterns, reflecting a forward-looking approach that balances that balances tradition and innovation. Figure 2. Mediterranean evil eye bead in the city Figure 2. Mediterranean evil eye bead in the city To reflect the cultural significance of the evil eye talisman, graphic patterns incorporating phrases such as To reflect the cultural significance of the evil eye talisman, graphic patterns incorporating phrases such as „nazar "nazar değmesin" (may you be protected from the evil eye) and "mavi boncuk" (blue bead) were featured on değmesin“ (may you be protected from the evil eye) and „mavi boncuk“ (blue bead) were featured on select pro select products. These elements serve as cultural references and establish a user-friendly communication -ducts. These elements serve as cultural references and establish a user-friendly communication style consistent style consistent with Mavi's brand identity (Figure 3). For the knitwear group, fabric research prioritized linen with Mavi‘s brand identity (Figure 3). For the knitwear group, fabric research prioritized linen and linen-blend and linen-blend options. Cotton fabrics with a linen-like appearance were also considered to provide affordable options. Cotton fabrics with a linen-like appearance were also considered to provide affordable alternatives while alternatives while maintaining aesthetic appeal. maintaining aesthetic appeal. 3 264 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Figure 3. Evil eye themed slogans Figure 3. Evil eye themed slogans In the woven product group, natural and breathable materials such as linen and cotton were used, emphasizing Figure 3. Evil eye themed slogans In the woven product group, natural and breathable materials such as linen and cotton were used, emphasizing cool textures suitable for summer. Finishing processes included silicone and fabric softener treatments, cool textures suitable for summer. Finishing processes included silicone and fabric softener treatments, combined In the woven product group, natural and breathable materials such as linen and cotton were used, emphasizing combined with steam ironing, to enhance softness and achieve a natural look. The designs focused on unlined, with steam ironing, to enhance softness and achieve a natural look. The designs focused on unlined, minimalist cool textures suitable for summer. Finishing processes included silicone and fabric softener treatments, minimalist garments adaptable to various locations and occasions. Key pieces included long, unstructured garments adaptable to various locations and occasions. Key pieces included long, unstructured items designed combined with steam ironing, to enhance softness and achieve a natural look. The designs focused on unlined, items designed for versatility and elegance (Figure 4). for versatility and elegance (Figure 4). minimalist garments adaptable to various locations and occasions. Key pieces included long, unstructured items designed for versatility and elegance (Figure 4). Figure 4. Minimal Logo Design Details 3.2 Functional Features Figure 4. Minimal Logo Design Details Figure 4. Minimal Logo Design Details The functional features of garments are defined by specific attributes that enhance user comfort, performance, 3.2 Functional Features 3.2 Functional Features and utility. These features are developed through advanced materials and processing techniques, enabling The functional features of garments are defined by specific attributes that enhance user comfort, performance, and The functional features of garments are defined by specific attributes that enhance user comfort, performance, garments to meet specialized needs (Sela et al., 2020). Such developments are facilitated by various textile utility. These features are developed through advanced materials and processing techniques, enabling garments and utility. These features are developed through advanced materials and processing techniques, enabling industry techniques and materials, ensuring versatility and suitability for specific applications. In the post-to meet specialized needs (Sela et al., 2020). Such developments are facilitated by various textile industry garments to meet specialized needs (Sela et al., 2020). Such developments are facilitated by various textile pandemic period, evolving consumer expectations have emphasized the importance of flexibility, sustainability, industry techniques and materials, ensuring versatility and suitability for specific applications. In the post-techniques and materials, ensuring versatility and suitability for specific applications. In the post-pandemic period, and functionality in clothing, positioning these attributes as key determinants of the industry's future (Zhang et pandemic period, evolving consumer expectations have emphasized the importance of flexibility, sustainability, evolving consumer expectations have emphasized the importance of flexibility, sustainability, and functionality in al., 2023). and functionality in clothing, positioning these attributes as key determinants of the industry's future (Zhang et clothing, positioning these attributes as key determinants of the industry‘s future (Zhang et al., 2023). al., 2023). This study prioritizes ease of use in modern clothing designs, featuring wrinkle-free fabrics and ergonomic cuts. Designs promoting comfort and freedom of movement are further supported by the use of breathable This study prioritizes ease of use in modern clothing designs, featuring wrinkle-free fabrics and ergonomic cuts. This study prioritizes ease of use in modern clothing designs, featuring wrinkle-free fabrics and ergonomic materials. Sustainability goals are emphasized through the selection of durable fabrics that extend garment Designs promoting comfort and freedom of movement are further supported by the use of breathable materials. cuts. Designs promoting comfort and freedom of movement are further supported by the use of breathable lifecycles. Stylish yet comfortable knit fabrics are prioritized for the +30 age group, while Mediterranean-Sustainability goals are emphasized through the selection of durable fabrics that extend garment lifecycles. Stylish materials. Sustainability goals are emphasized through the selection of durable fabrics that extend garment inspired woven fabrics and patterns are prominent for the +20 age group. yet comfortable knit fabrics are prioritized for the +30 age group, while Mediterranean-inspired woven fabrics and lifecycles. Stylish yet comfortable knit fabrics are prioritized for the +30 age group, while Mediterranean-patterns are prominent for the +20 age group. inspired woven fabrics and patterns are prominent for the +20 age group. Brands can effectively address post-pandemic consumer demands by developing designs tailored to age-specific preferences, fabric innovations, and cultural inspirations. Implementing such insight-driven design Brands can effectively address post-pandemic consumer demands by developing designs tailored to age-specific Brands can effectively address post-pandemic consumer demands by developing designs tailored to age-strategies ensures that garments meet aesthetic and functional requirements while contributing to a more preferences, fabric innovations, and cultural inspirations. Implementing such insight-driven design strategies specific preferences, fabric innovations, and cultural inspirations. Implementing such insight-driven design sustainable and versatile wardrobe approach. ensures that garments meet aesthetic and functional requirements while contributing to a more sustainable and strategies ensures that garments meet aesthetic and functional requirements while contributing to a more versatile wardrobe approach. sustainable and versatile wardrobe approach. 4. CONCLUSIONS 4. CONCLUSIONS pandemic have demonstrably altered individual shopping habits, clothing preferences, and overall lifestyles, This study reveals the profound influence of large-scale events, such as pandemics, on societal lifestyles and This study reveals the profound influence of large-scale events, such as pandemics, on societal lifestyles and their their subsequent impact on the fashion and textile industries. Specifically, societal crises like the COVID-19 resulting in substantial transformations within the fashion sector. subsequent impact on the fashion and textile industries. Specifically, societal crises like the COVID-19 pandemic pandemic have demonstrably altered individual shopping habits, clothing preferences, and overall lifestyles, have demonstrably altered individual shopping habits, clothing preferences, and overall lifestyles, resulting in 4. CONCLUSIONS their subsequent impact on the fashion and textile industries. Specifically, societal crises like the COVID-19 This study reveals the profound influence of large-scale events, such as pandemics, on societal lifestyles and These evolving consumer needs and expectations have permeated every facet of product design, from resulting in substantial transformations within the fashion sector. substantial transformations within the fashion sector. patterns and material composition to functionality and intricate details. During the pandemic, priorities shifted These evolving consumer needs and expectations have permeated every facet of product design, from These evolving consumer needs and expectations have permeated every facet of product design, from patterns patterns and material composition to functionality and intricate details. During the pandemic, priorities shifted and material composition to functionality and intricate details. During the pandemic, priorities shifted towards 4 4 265 29–30 May 2025, Ljubljana, Slovenia physical health and personal comfort, compelling fashion brands to adapt their product lines accordingly. Factors such as comfort and practicality became paramount, leading to an increased emphasis on functionality and con-venience in design. Consequently, the fashion industry must transcend traditional aesthetic concerns and embrace functional appro-aches that align with contemporary consumer lifestyles and expectations. The previously distinct boundaries between traditional workwear and casual clothing have blurred, with hybrid, multifunctional textile products gai-ning prominence. This trend has further diminished the demarcation between sportswear and classic business at-tire, characterized by the emergence of flexible and comfortable cuts as defining features across both categories. In conclusion, large-scale crises act as catalysts for industry-wide adaptation in response to evolving consumer expectations. The fashion industry, in particular, has evolved beyond purely aesthetic considerations to encom-pass broader societal and environmental impacts within its processes. This shift has propelled the adoption of more sustainable and conscious approaches to design and production. To address these changing demands, fashion brands are increasingly integrating environmentally friendly materials and enhancing production efficien-cy, reflecting a growing commitment to sustainability. 5. 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Advanced Functional Materials, 33. https://doi.org/10.1002/adfm.202301607. 266 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Asst. Prof. Dr. Özgür Ceylan Emel Aydin Eskişehir Technical University +90 545 963 03 71 emelaydintt@gmail.com +90 (222) 213 77 77 / 7823 ozgurceylan@eskisehir.edu.tr Irmak Taş +90 535 105 86 57 irmaktas92@gmail.com Nesligül Kiliç +90 534 731 90 08 nesligulkilic@gmail.com Eskişehir Technical University Neval Ergun, Aslihan Arpinar, and Tuğçe Kaynak, MAVİ GİYİM SANAYİ VE TİCARET A.Ş. 267 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION INNOVATING TOGETHER: DIGITAL FASHION LEARNING THROUGH COLLABORATION Marjeta Čuk1, Elena Fajt1, Alenka More1, Nastja Sagadin Grmek1 1 and Tanja Nuša Kočevar 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Digital fashion is reshaping the industry through 3D modeling, virtual prototyping, and extended reality (XR). As digital tools become essential, education must adapt by integrating collaborative and interdisciplinary learning. This study presents the Erasmus+ project ME-YOU-US and its study module “Futuring US through Virtual Touch”, which engaged students, educators, and industry experts in digital fashion design. The project combined CLO3D, digital prototyping, and speculative design with hands-on material exploration to develop future fashion scenarios. Collaborative learning across disciplines enhanced technical skills, creativity, and teamwork. The results, including digital garments, virtual environments, and physical scale models, highlight the importance of balancing digital innovation with traditional craftsmanship. This approach prepares students for an evolving fashion industry by fostering both technological proficiency and material awareness, ensuring they contribute to a more sustainable and inclusive future. Keywords: Digital fashion, 3D modeling, virtual prototyping, collaborative learning, extended reality (XR), susta-inable design. 1. INTRODUCTION Digital fashion is the intersection of fashion design, technology and virtual environments, focusing on clothing and accessories that exist digitally rather than physically. Advances in 3D modelling, augmented reality (AR) and virtual reality (VR) have catapulted digital fashion into the mainstream and transformed the way designers create, present and market their work (Sayem, 2022). As the industry moves towards digitalization, fashion education needs to evolve to equip future designers with the necessary technical and conceptual skills. Integrating digital tools into fashion education improves design, production and business processes while promo-ting sustainability. Virtual prototyping, digital materials and immersive technologies allow designers to explore new creative possibilities while reducing waste. However, mastering these tools requires interdisciplinary collaboration between designers, software developers and industry experts (Santos, 2020). Collaborative learning plays a key role in fostering innovation by encouraging students to engage in teamwork, problem solving and critical thinking. Studies have shown that collaboration increases student motivation, persistence and engagement while accele-rating deeper understanding through meaningful social interactions (Scager, 2017). In digital fashion education, teamwork between students, faculty and industry professionals bridges the gap between theory and practice. By working together on real projects, students develop important digital skills and learn from different perspectives. Collaborative problem solving has been shown to strengthen critical thinking and adaptability, essential qualities for designers operating in a rapidly evolving industry (Xu, 2023). This paper explores the importance of collaboration in digital fashion education, drawing on findings from the Erasmus+ project ME-YOU-US. Based on the development of a study module concentrating on future appli-cations of virtual fashion, strategies for effective interdisciplinary learning are identified and the challenges and opportunities of integrating digital tools into fashion education are discussed. 268 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL Since September 2022, the Chair of Textile and Clothing Design at the Faculty of Natural Sciences and Engine-ering (NTF) at University of Ljubljana has been part of the Erasmus+ project Me-You-Us. This initiative promotes digital 3D skills in textile and apparel design, focusing on diversity, inclusion and sustainability. Over a three-year period, the project brings together three institutions — Designskolen Kolding (Denmark), Willem de Kooning Academy (Netherlands) and the University of Ljubljana (Slovenia) — to develop nine open-access educational modules that use digital tools to promote education in textile and apparel design. The final module, Module 3, focused on the US, while the overarching title of the first module was ME and of the second YOU. Module 3 dealt with developments in virtual fashion and its future applications. The aim was to train educators and students alike in the new technologies and software applications and to create modules that explore future scenarios in fashion and virtual fashion. 2.1 Development of the Study Modul “Futuring US through virtual touch” Module 3, conducted at NTF, focused on the communities we formed to create a collaborative teaching envi-ronment with different co-educators. First with the groups of students, then with the mentors, the teachers of the same department and then more broadly with the teachers and the students of the other department, guest lecturers and industry. The project carried out in the study module aimed to design speculative concepts that present future scenarios for people‘s lives and their clothes. The design process included creating physical scale models of environments and textures and the use of CLO3D for the virtual production of clothing prototypes. The students then moved on to other digital tools such as 3D application Blender where they developed speculative virtual spaces with avatars and digital garments. Collaboration with students was a fundamental component of the planning phase for the module. During this phase, students were actively invited to participate in discussions and evaluations of previous modules and collaborative efforts, thereby creating an environment conducive to the generation of new propos-als and ideas. The primary objective was to engage students in the planning process, enabling them not only to execute the project but also to contribute to its development. This inclusive approach fostered greater motivation and enthusiasm among students, as they felt empowered to tackle new challenges and influence the direction of the module. By involving students in the shaping of the project, we aimed to enhance their commitment and investment in the learning experience. The integration of five courses: Fashion design, Digital 3D design, Textile design, Art styles and Presentation techniques, required extensive coordination, but the block study format al-lowed students to focus on one project, which encouraged their engagement. The input of all educators in the form of lectures, tutorials and skills delivery played an important role in the development of the project. Throughout the module, we organized two “US Days,” dedicated to promoting connections between students and mentors, aligned with the overarching theme of the module. The first “US Day,” planned by the mentors, was scheduled at the outset of the module. This initial event provided an opportunity to present the final project plan and allowed students to gradually acclimate to the new challenges ahead. The day was intentionally held outside the traditional educational environment, encouraging participants to engage with one another and with nature. In contrast, the second “US Day” was designed by the students themselves. They organized a roundtable fo-cused on discussions surrounding digital and virtual fashion. This event featured invited speakers from both the institution and the industry, who addressed pertinent concerns and questions related to the topic. This student-led initiative not only facilitated meaningful dialogue but also empowered students to take an active role in shaping the discourse surrounding their field of study. Collaboration in digital fashion education goes beyond traditional teamwork; it advances an ecosystem of knowl-edge sharing in which students and teachers jointly develop learning resources and technical solutions. In this context, students and teachers developed a platform for sharing information about technical challenges and answers related to working in a 3D digital environment. This collaborative approach enabled students to support each other in mastering complex digital tools and reinforced peer learning as a fundamental aspect of skills de-velopment. Peer learning, as described by Boud Et al. (Boud, 1999), increases student engagement, deepens understanding, and improves problem-solving skills. In a rapidly evolving field such as digital fashion, where 269 29–30 May 2025, Ljubljana, Slovenia technological advances are constantly reshaping design processes, peer collaboration allows for the sharing of different perspectives and hands-on problem solving. Through collaboration, students develop adaptability, technical dexterity and the ability to critically evaluate digital design solutions. The integration of student problem solving and professional guidance creates a dynamic learning experience that prepares future designers for the challenges of the industry. During the module, there was an interdisciplinary collaboration with students and tutors from two courses of the Graphic Arts programme. Students had the task of further developing the projects with the help of multimedia applications and integrating the work of the textile and fashion design students. They actively participated in the interim and final presentations, gaining an insight into the conceptual, creative and technical challenges faced by their fellow students. This engagement allowed them to critically evaluate and refine the integration of avatars and virtual environments created by the design student teams. The collaboration between textile, fashion and graphic arts students created a dynamic, interdisciplinary learning environment that strengthened technical skills, concep-tual development and teamwork. The most important advantages of collaborative work are - Interdisciplinary exchange: Graphic arts students learned about materials, garment construction and digital fash-ion, while fashion and textile students explored digital visualisation, multimedia and storytelling. - Technical progress: Fashion students improved 3D design and digital rendering, while graphics students en-hanced their skills in animation, virtual spaces and multimedia presentation. - Stronger storytelling: Both groups refined their ability to visually convey ideas through avatars, environments and fashion elements. - Adaptability and problem-solving skills: Students navigated through various creative processes, adapting work-flows and developing innovative solutions. - Improved teamwork and communication: Joint presentations and discussions encouraged the exchange of ideas, feedback and collaboration. By promoting peer learning, the module prepared students for the evolving digital fashion and multimedia industry. 3. RESULTS WITH DISCUSSION The results of the project ranged from essays on future scenarios, reflections on guest lectures, digital clothing, handmade textures and scale models of spaces to virtual scenes of digital fashion, also shown with XR. The first part of the module included the creation of the concept, the development of textures, the development of the environment and the virtual prototyping of the garment in CLO3D. Figure 1 shows a dress created in the virtual prototyping software CLO3D and a handmade scale model of the environment. In the second part of the module, the students worked with Blender, where they upgraded the clothing, created the desired avatar and designed the environment. This was based on the concept developed and the results of the first part. Figure 2 shows one of the results, the avatar whose garment was created in CLO3D and then modified and completed in Blender. 270 first part of the module included the creation of the concept, the development of textures, the development of the environment and the virtual prototyping of the garment in CLO3D. Figure 1 shows a dress created in the virtual prototyping software CLO3D and a handmade scale model of the environment. In the second part of the module, the students worked with B 29–30 May 2025, Ljubljana, Slovenia lender, where they upgraded the clothing, created the desired avatar and designed the environment. This was based on the concept developed and the results of the first part. Figure 2 shows one of the results, the avatar whose garment was created in CLO3D and then modified and completed in Blender. Figure 1: Digital garment created in CLO3D (left) and the physical scale model of the environment (right). Figure 1: 29–30 May 2025, Ljubljana, Slovenia Digital garment created in CLO3D (left) and the physical scale model of the environment (right). Authors: Lia Sara Authors: Lia Sara Likar and Taja Sejdić Likar and Taja Sejdić 3 Figure 2: Figure 2: Avatar modified and completed in Blender. Authors: Avatar modified and completed in Blender. Authors: Taša Blatnik and Brina Cotič Taša Blatnik and Brina Cotič The avatars and digitised environments were ultimately the basis for the further work of the graphic arts students, students, who considered further visualisation of the avatars in virtual environments and other advanced The avatars and digitised environments were ultimately the basis for the further work of the graphic arts who considered further visualisation of the avatars in virtual environments and other advanced visualisations of visualisations of the avatars. Figure 3 shows the visualisations and illustrated designs developed by the graphic the avatars. Figure 3 shows the visualisations and illustrated designs developed by the graphic design students, design students, and Figure 4 shows a virtual atmosphere created in the Unreal Engine from elements of the and Figure 4 shows a virtual atmosphere created in the Unreal Engine from elements of the environment devel-environment developed by the design students. oped by the design students. . 271 Figure 2: Avatar modified and completed in Blender. Authors: Taša Blatnik and Brina Cotič The avatars and digitised environments were ultimately the basis for the further work of the graphic arts students, who considered further visualisation of the avatars in virtual environments and other advanced 29–30 May 2025, Ljubljana, Slovenia visualisations of the avatars. Figure 3 shows the visualisations and illustrated designs developed by the graphic design students, and Figure 4 shows a virtual atmosphere created in the Unreal Engine from elements of the environment developed by the design students. . 29–30 May 2025, Ljubljana, Slovenia Figure 3: Rendered and sketched ideas for creating a common space for all avatars by graphic design students. Authors: Figure 3: Ren dered and sketched ideas for creating a common space for all avatars by graphic design Judita Kociper, Lina Peharc, Rajović Milena students . Authors: Judita Kociper, Lina Peharc, Rajović Milena 4 Figure 4: Virtual environment created in the Unreal Engine from elements of an environment developed by Figure 4: design students. Author: Marko Šiškovič Virtual environment created in the Unreal Engine from elements of an environment developed by de- sign students. Author: Marko Šiškovič 4. CONCLUSIONS 4. CONCLUSIONS The evolving model of digital fashion education emphasizes the critical role of collaboration between students, educators and industry partners. This synergy fosters innovation, improves learning outcomes and bridges the The evolving model of digital fashion education emphasizes the critical role of collaboration between students, gap between theory and practice. Wh ile digital tools and 3D technologies are transforming design, manual educators and industry partners. This synergy fosters innovation, improves learning outcomes and bridges the skills and hands-on experimentation remain essential to understanding materiality, craftsmanship and gap between theory and practice. While digital tools and 3D technologies are transforming design, manual skills creativity. By combining collaborative learning with a balanced mix of digital and manual methods, education and hands-on experimentation remain essential to understanding materiality, craftsmanship and creativity. By programs can prepare students to meet the diverse demands of the fashion industry. Graduates are not only combining collaborative learning with a balanced mix of digital and manual methods, education programs can pre technologically savvy, but also rooted in traditional design principles, enabling them to make a meaningful -pare students to meet the diverse demands of the fashion industry. Graduates are not only technologically savvy, contribution to a sustainable and inclusive future for fashion. but also rooted in traditional design principles, enabling them to make a meaningful contribution to a sustainable and inclusive future for fashion. The dynamic nature of digital fashion education emphasizes the importance of collaboration between students, faculty and industry partners. This synergy encourages innovation, improves learning outcomes and bridges the gap between theory and practice. Understanding materiality, craftsmanship and originality still requires manual skills and hands-on experimentation, even as digital tools and 3D technologies revolutionize design. Educational programs can equip students for the diverse demands of the fashion industry by integrating collaborative learning with a balanced combination of digital and manual approaches. Graduates can make an important contribution to a sustainable and inclusive fashion industry as they are not only technically adept but also have a sound knowledge of classic design concepts. 5. REFERENCES 272 Santos, L. R., Montagna, G., & Neto, M. J. P. (2020). The virtualization of the fashion product. V G. Di 29–30 May 2025, Ljubljana, Slovenia The dynamic nature of digital fashion education emphasizes the importance of collaboration between students, faculty and industry partners. This synergy encourages innovation, improves learning outcomes and bridges the gap between theory and practice. Understanding materiality, craftsmanship and originality still requires manual skills and hands-on experimentation, even as digital tools and 3D technologies revolutionize design. Educational programs can equip students for the diverse demands of the fashion industry by integrating collaborative learning with a balanced combination of digital and manual approaches. Graduates can make an important contribution to a sustainable and inclusive fashion industry as they are not only technically adept but also have a sound knowl-edge of classic design concepts. 5. REFERENCES Santos, L. R., Montagna, G., & Neto, M. J. P. (2020). The virtualization of the fashion product. V G. Di Bucchianico, C. S. Shin, S. Shim, S. Fukuda, G. Montagna, & C. Carvalho (Ur.), Advances in Industrial Design (Let. 1202, str. 820–830). Springer International Publishing. Sayem, A. S. M. (2022). Digital fashion innovations for the real world and metaverse. International Journal of Fashion Design, Technology and Education, 15(2), 139–141. Scager, K., Boonstra, J., Peeters, T., Vulperhorst, J., & Wiegant, F. (2016). Collaborative learning in higher education: Evoking positive interdependence. CBE—Life Sciences Education, 15(4), ar69. Xu, E., Wang, W., & Wang, Q. (2023). The effectiveness of collaborative problem solving in promoting students’ critical thinking: A meta-analysis based on empirical literature. Humanities and Social Sciences Communications, 10(1), 16. Boud, D., Cohen, R., & Sampson, J. (1999). Peer learning and assessment. Assessment & Evaluation in Higher Education, 24(4), 413–426. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Tanja Nuša Kočevar Marjeta Čuk Alenka More and Engineering and Engineering Department of Textiles, Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Graphic Arts and Design Snežniška ulica 5, Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana University of Ljubljana Snežniška ulica 5, Ljubljana Snežniška ulica 5, Ljubljana marjeta.cuk@ntf.uni-lj.si alenka.more@ntf.uni-lj.si tanja.kocevar@ntf.uni-lj.si Elena Fajt Nastja Sagadin Grmek University of Ljubljana University of Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška ulica 5, Ljubljana Snežniška ulica 5, Ljubljana elena.fajt@ntf.uni-lj.si nastja.sagadingrmek@ntf.uni-lj.si 273 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION SUSTAINABILITY AT KOTO Nastja Sagadin Grmek1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The fashion industry is undergoing a transformative shift towards sustainability, requiring a compre-hensive understanding of sustainable design principles and their importance in educational curricula. This paper explores the multifaceted nature of sustainability, which has evolved from a focus on social change to encompass environmental, social, and economic responsibilities. It emphasizes the importance of education in fostering a culture of sustainability among future designers, highlighting the need for practical applications that align with in-dustry practices. The paper presents various sustainable design projects conducted at the Department of Textile and Clothing Design at the University of Ljubljana, which were jointly presented through multiple activities with the support of the HUD fund (Humanistic, Artistic, and Social Science Research) in a project called „Sustainability at KOTO.“ Ultimately, this paper advocates for a holistic approach to fashion education that empowers designers to navigate the complexities of sustainability and contribute to a more responsible and equitable industry. Keywords: sustainability in fashion, responsible design, public awareness, fashion education 1. INTRODUCTION Sustainability in the fashion industry has gained significant attention over recent decades, evolving from a social concern into a mainstream imperative. The term „sustainable“ itself has become multifaceted and often misinterpreted, frequently conflated with concepts like recycling and environmentalism. Originally rooted in social change aimed at alleviating global poverty, the meaning of sustainability has diversified to encompass various dimensions, including environmental, social, and economic responsibilities (Gwilt and Rissanen, 2011). As the industry confronts the pressing challenges of climate change and resource depletion, understanding sustainable design principles and integrating them into educational curricula has become crucial. This paper delves into the sustainable design principles in fashion and textile design and highlights the importance of education in fostering sustainable practices within the industry. 2. SUSTAINABLE DESIGN PRACTICES IN FASHION The concept of sustainable fashion transcends mere eco-friendly materials or ethical labor practices; it represents a holistic approach to design that considers the life cycle of garments from conception to disposal. The rise of ethical fashion in the late 1990s marked a pivotal shift, with consumers increasingly demanding transparency and accountability from the industry (Henninger et al., 2016). Yet, as the fashion sector grapples with over 70 definitions of sustainability, the ambiguity surrounding what constitutes sustainable fashion poses challenges for practitioners (The True Cost, 2015). The True Cost documentary emphasizes that sustainable fashion must address the social, environmental, and economic impacts of production, urging designers to rethink traditional processes and adopt innovative frameworks. A growing body of designers recognizes their responsibility to implement sustainable practices, yet many express uncertainty in navigating these frameworks. To effectively integrate sustainable design principles, it is essential to critique conventional design processes and explore alternative methodologies that promote holistic engagement with sustainability (Gwilt and Rissanen, 2011). This shift towards a circular economy, characterized by principles such as traceability, transparency, and circularity, offers a pathway for the industry to mitigate its environmental footprint. The linear „cradle to grave“ model that dominates current production practices must evolve into a „cradle to cradle“ approach, where waste is minimized, and materials are continuously reintegrated into the production cycle (Rinaldi, 2019). 274 29–30 May 2025, Ljubljana, Slovenia Furthermore, the fashion industry’s significant contribution to pollution and resource depletion necessitates a collective response. The UN Sustainable Development Goals (SDGs) emphasize the need for enhanced aware-ness and education around sustainable practices, recognizing that informed consumers and designers are pivotal to driving change (Rinaldi, 2019). The circular economy paradigm not only promotes responsible consumption but also encourages innovation in materials, design concept, and production techniques, facilitating a transition towards sustainability. It is important to mention also cultural sustainability, which is a response to society’s shifting attitudes towards inclusivity, representation, and respect for others and their cultural heritage, as well as the awareness and preser-vation of cultural variety.(Loach et al., 2017) The conservation and development of cultural practices, material culture, and craft to transmit culture entails un-derstanding past biases and attempting to resolve them. Moreover, acknowledging and preserving cultural variety, inclusivity, representation, and respect for people and their cultural history are responses to cultural sustainability. It encourages preserving cultural practices and material culture to maintain cultural diversity and identity. It also acknowledges the significance of craft as a form of cultural language. (Wang et al., 2025) 3. THE IMPORTANCE OF EDUCATION IN SUSTAINABLE FASHION Education plays a critical role in implementing sustainable practices within the fashion industry. As fashion evol-ves, aligning educational curricula with sustainability principles is essential to prepare future designers and fashion professionals for the challenges ahead (Wang et al., 2025). Recent advancements in digital fashion and the adoption of technologies like 3D design tools present unique opportunities for hands-on learning, enabling students to develop essential skills in problem-solving and adaptive thinking (Särmäkari, 2023). However, the cur-rent educational frameworks often fall short, focusing predominantly on theoretical instruction rather than practical applications that reflect the realities of the industry. The European Commission has recognized textiles as a priority category for the circular economy, highlighting the urgent need for educational initiatives that bridge the knowledge gap in sustainable textile design (Wang et al., 2025). Since up to 80% of a product‘s environmental impact is determined during the design phase, equipping aspiring designers with the tools to create durable and recyclable garments is cruucial (Wang et al., 2025). By fostering a culture of sustainability within educational institutions, we can cultivate a new generation of designers who are not only aware of their environmental responsibilities but also equipped to innovate and lead the industry towards a more sustainable future. 3.1 Sustainable practice at Department of Textile and Clothing Design At the core of the main design courses at the Department of Textile and Clothing Design, we are fo-cused on developing sustainable design projects. These topics are primarily approached in practi-cal terms, with some rare projects being soley conceptual. We guide students to reflect on the is-sues and potential solutions that are currently applicable and to speculate and inovate new processes. We strive to use environmentally friendly methods and concepts, ecological processes, and reduce environmen-tal impacts: we incorporate principles of recycling and upcycling, working with donated or discarded materials and products, dead stock materials, recycling pre-owned clothing, and using environmentally friendly materials and technologies. We employ digital printing techniques, laser cutting, and engraving, and introduce new digital programs for modeling and visualizations that reduce paper and textile material usage during the design and pro-duct development phase. We encourage students to design for long lifespan, including multifunctional garments. We also promote the preservation of local crafts and cultural heritage by teaching handcrafts and developing projects related to preserving Slovenian lace. In these projects, we collaborate with socially engaged non-govern-mental organizations and individuals. We focus on diverse target groups by promoting intergenerational knowled-ge transfer between the elderly and younger generations or, for example, cultural exchange between refugees and students. We encourage equality and social justice, emphasizing inclusivity, diversity and gender equality. 275 29–30 May 2025, Ljubljana, Slovenia As a Higher Educational Institution, we recognize that our responsibilities extend beyond merely educating our students and guiding them toward sustainable outcomes. It is essential to disseminate our projects to a broader audience in order to enhance the visibility of the research and artistic endeavors produced by the Department of Textile and Clothing Design (KOTO). By doing so, we aim to raise awareness and stimulate self-reflection and critical thinking among consumers. This initiative seeks to foster a greater sense of responsibility and encourage a shift in shopping habits within the wider public. Some of our sustainable projects have been presented to the wider public with the support of the HUD Fund, as we recognize that by raising awareness of problems and showcasing various topics related to sustainable fashion and socially engaged projects through textile media and cultural traditions, we can influence greater understan-ding of these issues, change attitudes toward them, and ultimately encourage social change. 3.2 »Sustainability at KOTO« With the project »Sustainability at KOTO« we carried out various activities aimed at engaging and raising awa-reness among the wider public about the importance of sustainability in fashion and textile creation. By presenting information on sustainable practices through our projects and highlighting the negative impacts of fast fashion, we raised awareness of environmental and societal effects, encouraged various target groups to reconsider shopping habits, support local cultural heritage, recognize the importance of local economies and brands, and educate on inclusivity in fashion and political and cultural correctness in contemporary design. As part of the project, we carried out six activities that represented student projects, developed in academic year 2023-2024, and approached sustainability in textiles and fashion in different ways. - The first activity, »Prinesi & Odnesi“ (eng. Bring&Take) took place in collaboration with the Rog Center and was a clothing exchange event as part of the „Fashion Revolution“ initiative and movement - The second activity, „NTFsKRIM,“ (eng. NTFwithKRIM) was organized to celebrate the 40th anniversary of the Krim Handball Club. We presented a collection of recycled clothing made from sports jerseys at this event. - In July, we held an embroidery workshop and presented the „Skupnostna Vezenina“ (eng. Community Embroidery). The workshop was aimed at intercultural collaboration and was carried out in partnership with the Terra Vera association, artist Tjaša Bavcon, refugees from Ukraine, Poland, Turkey, and Kaza-khstan, and students. - As part of the „Svobodni ljudje“ (eng. Free People) exhibition in Idrija, which explored the artistic place- ment of bobbin lace within the mining cultural heritage (cultural sustainability), we conducted guided tours. - The exhibition of the „Niti&Kode“ (eng. Threads & Codes) project took place at the „Dobimo se pred Šku- cem“ event. This project explores the central theme „Human-AI,“ where we carry out projects related to sustainable processes, including digitalization and the use of artificial intelligence. - The final activity in December was held as part of the „Modnovanje“ event, where we presented jewelry created in collaboration with the Rog Center. It was a combination of hand-crafted and digitally designed fashion accessories. 3.2.1 Activity 1: Clothing exchange „Prinesi & Odnesi“ as part of fashion revolution week. (Activity leader: full prof. Elena Fajt) Year 2024 marks the 11th anniversary of the tragic event when the eight-story Rana Plaza factory in Bangladesh collapsed, burying more than 1,100 people. Following this tragic incident, the international organization Fashion Revolution was established, which every year organizes Fashion Revolution Week to commemorate and raise awareness of this event, highlighting the urgent need for change in the fashion and textile industrie. For the first time this year, KOTO, UL joined the event at our department, in collaboration with Center Rog, by organizing a clothing swap that also included an awareness campaign. With this event, we aimed to reintegrate clothing into a cycle of reuse. We invited Slovenian fashion designers to participate, as we wanted to highlight domestic brands, their quality, and the importance of ethical and local garment production. 29 Slovenian designers participated at the event. 276 29–30 May 2025, Ljubljana, Slovenia With the clothing swap, we sought to support more sustainable approaches in fashion and consuming, as well as create space for raising awareness about the consumer culture, environmental impact and social injustice. The event was aimed at both professionals and the wider public. 3.2.2 Activity 2: Presentation of the »NTFsKRIM« project with a fashion show celebrating the 40th anniversary of the krim mercator handball club. (Mentors: full prof. Almira Sadar, full prof. Elena Fajt, prof. Nataša Peršuh, assist. Nataša Hrušič, assist. Sara Valenci, assist Alenka More, Nina Glavič, Mojca Košir) The »NTFsKRIM« project was created in collaboration with the handball club Krim Mercator Ljubljana. The competition jerseys, which served as both the official wear for the handball players and a means of uniting fans with the club, became an unlimited source of inspiration and a tool for non-verbal communication between the players and students during the workshop. The jerseys were recycled and upcycled using various techniques to create unique garments that represent students‘ exploration. The design process included various solutions such as weaving, crocheting, laser-cutting of jerseys, tracksuits, balls, and nets. The collection featuring soft-separates, was completed with denim bottoms. The contemporary collection of women‘s clothing was presented by the club‘s handball players at a special event, which allowed us to share the project with a wider audience, one that our projects don‘t typically engage with. 3.2.3 Activity 3: Embroidery workshop and presentation of the „Skupnostna Vezenina“ project. (Mentor: associate prof. Katja Burger Kovič) »Skupnostna Vezenina“ project, an initiative for the social activation of women from different cultural backgrounds, is based on the use of textile handicrafts and the appreciation of textile cultural heritage. Workshop participants from Ukraine, Turkey, Poland, and Kazakhstan presented their modern interpretations of traditional embroidery, created using machine embroidery techniques. Workshop aimed at the exchange and transfer of knowledge, as well as the establishment of connections between Slovenia’s embroidery cultural heritage and the aforementioned countries. The presentation was conveyed through the visual language of prototype-designed modern community embroidery. As part of this activity, art and textile creation were used as tools for the empowerment of women from vulnerable groups, going beyond the role of expressive means to serve as a foundation for establishing dialogue and mutual understanding between different cultures, thereby strengthening intercultural solidarity and promoting cultural diversity. The participants, which included women from vulnerable groups and a group of design students, were encouraged to develop their own and possibly joint projects, which allowed for the enrichment of their personal development and the enhancement of their professional potential. An important aspect of this activity was the final evaluation, conducted in the form of a guided dialogue. This phase allowed participants to delve into a reflection on their artistic works and analyze their inner creative processes. 3.2.4 Activity 4: Four guided tours of the „Svobodni ljudje“ exhibition. (Menthors: full prof. Marija Jenko, associate prof. Katja Burger Kovič, assist. Jana Mršnik, Nina Glavič, Marjeta Čuk, Mojca Košir, Maja Svetlik (ČŠI)) The project involved the artistic placement of bobbin lace within the mining cultural heritage—specifically the Jožef Shaft complex in Idrija. The project, with its approach as a contemporary cultural value, entered the local community, which preserves, develops, and spreads the art of bobbin lace among the youth. We used the bobbin lace in the context of contemporary creative practices and in relation to architectural heritage. This context was transformed into the functionality of the lace, where the craft technique is understood as a design factor in space. The exhibition was intended for a wider audience; the Idrija Lace Festival attracts thousands of visitors, especially young people who are entering various professions, possibly related to cultural heritage, tourism, technical culture, as well as craft and industrial design. Bobbin lace-making is practiced by a wide range of social groups, including both young and older individuals, particularly many women, for whom this activity provides not only additional income but also social empowerment. We organized several expert-led tours of the exhibition, to which we invited representatives from various fields, each emphasizing the meaning of the exhibition and its long-term cultural and economic significance from their own perspective. 277 29–30 May 2025, Ljubljana, Slovenia 3.2.5 Activity 5: Exhibition of the »Niti&Kode«. (Mentors: assist.prof. Arijana Gadžijev, assist. Nastja Sagadin Grmek) The exhibition took place as part of the event „Dobimo se pred Škucem.“ The presented project explores the overarching theme „Human-AI,“ which inspired our projects related to sustainable processes, including digitalization and the use of artificial intelligence. The student works, including actual use of AI as well as conceptual thinking and reflecting was in both, material execution and virtual presentation. The project focuses on sustainable design of textiles and clothing using digital tools, virtual pattern models, and artificial intelligence applications, which also optimize their environmental impact. The main purpose of the event was to raise awareness about more sustainable design possibilities through the use of new tools. The event attracted various social and intergenerational groups from artistic and design circles, as well as the wider public. We opened the exhibition on one of the most visited days of the „Dobimo se pred Škucem“ event, which received significant media support and further contributed to its success. 3.2.6 Activity 6: Presentation of the handcrafted and digitally made jewelry „Nakit, nosi me“. (Mentors: prof. Nataša peršuh, assist. Nataša Hrupič, expert associate Peter Dragolič) As part of the „Nakit, nosi me“ project, students explored the possibilities and work environment of the laboratories at the Rog Center. They researched various classical and innovative materials and techniques applicable in the processes of contemporary jewelry design. Innovative sustainable solutions in design, production, and application of body jewelry were realized by the students through various techniques and materials, primarily bronze and brass, which, as a new non-textile medium, represented an inexhaustible source of artistic articulation. The result was a diverse range of jewelry collections, with individual pieces combining traditional handcraft techniques in goldsmithing and textiles, as well as new technologies such as laser cutting and 3D printing. The project was presented as part of the „Modnovanje“ event, which is our largest cultural event in the second half of the calendar year. It has become a traditional presentation of student works in the form of exhibitions that are open to the professional public, wider audiences, students, and potential students over a long period of time. 4. CONCLUSION In conclusion, integrating sustainable design principles into the fashion industry is essential for tackling the significant social and environmental challenges we face today. Education plays a crucial role as a catalyst for change, equipping future designers with the knowledge and skills needed to navigate the complexities of sustainable fashion. By adopting holistic, circular approaches and prioritizing sustainability in both practice and education, the fashion industry can move towards a more responsible and equitable future. Through the activities carried out in „Sustainability at KOTO,“ we successfully showcased projects that each address a different yet equally important pillar of sustainability. These initiatives were made visible to a broader audience, an essential step in raising awareness and empowering consumer with the information. 5. REFERENCES: Gwilt, A., Rissanen, T., 2011. Shaping Sustainable Fashion; changing the way we make and use clothes, First edition. ed. Earthscan, London, UK and Washington, DC. Henninger, C.E., Alevizou, P.J., Oates, C.J., 2016. What is sustainable fashion? Journal of Fashion Marketing and Management 20, 400–416. https://doi.org/10.1108/JFMM-07-2015-0052 Loach, K., Rowley, J., Griffiths, J., 2017. Cultural sustainability as a strategy for the survival of museums and libraries. International Journal of Cultural Policy 23, 186–198. https://doi.org/10.1080/10286632.2016.1184657 Rinaldi, F.R., 2019. Fashion Industry 2030; Reshaping the Future Through Sustainability and Responsible Innovation, First edition. ed. Boconi University Press EGEA S.p.A., Milano. Särmäkari, N., 2023. Digital 3D Fashion Designers: Cases of Atacac and The Fabricant. Fashion Theory - Journal of Dress Body and Culture 27, 85–114. https://doi.org/10.1080/1362704X.2021.1981657 Wang, M., Murphy, R., Christie, I., 2025. Bringing Sustainable Practices, Fashion Shows, and Sociological Insights Together to Reinvigorate Sustainable Fashion Education. Sustainability (Switzerland). https://doi.org/10.3390/su17020631 278 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Nastja Sagadin Grmek Faculty of natural Sciences and Engineering Chair of textile and fashion design Aškerčeva cesta 12 1000 Ljubljana, Slovenija nastja.sagadingrmek@ntf.uni-lj.si 279 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION DESIGN OF A MATERNITY COLLECTION WITH MULTIFUNCTIONAL PROPERTIES Öykü Elmas1, Ekin Üstem1 and Ecem Alagöz1 1DAGİ Design Center, Turkey Abstract: Maternity clothes are products specially designed for pregnant women. The aim of these products is to create designs that are most suitable for the changes that occur in women’s bodies during this period and to pro-vide them with a comfortable use. However, since women experience such as body swelling and skin sensitivity not only during pregnancy but also after birth, they prefer comfortable, flexible and soft-touch products. (Sham-saei, Kazemi, Enteshary-Najafabadi & Borujeni,2022) The aim of this study is to create a collection with clothes that women could use both during pregnancy and postpartum. The main features of the products in the collection are that they are compatible with a protruding belly, light, soft, comfortable and have functional uses added for both pregnancy and breastfeeding . Keywords: sleepwear, loungewear, maternity, comfort, functionality 1. INTRODUCTION Comfort and clothing comfort are seen as the most important needs of women when considering both pregnancy and postpartum processes. In order to meet the prominent needs in this collection, designs were made by focu-sing on fabric and product details. Different quality fabrics were used in the products, and it was aimed to increase comfort and convenience by combining different quality fabrics with various product details. Women may have to spend most of their time at home during pregnancy and postpartum processes. For this reason, our products were planned for sleepwear and casual wear categories suitable for wearing at home. Products were designed for both upper and lower clothing. T-shirts, pants, dresses are the products designed for this collection. 2. EXPERIMENTAL In this collection, which is specially designed for women’s pregnancy and postpartum processes, we divided our products into two categories: sleepwear and lounge wear. Three different quality fabrics are used in products de-signed for sleepwear. These are siroviskon supreme, viscose camisole and cotton modal jersey. Modal blended jersey fabrics are preferred for lounge wear. The most requested features of products designed for pregnancy and postpartum are that they are soft and feel comfortable all day long. The reason for choosing modal and viscose fabrics in the collection is that they are both made of natural material which is cellulose and have a soft touch. In addition to the advantages of the fabric features of the products, the functionality of the products has been in-creased by adding different features such as adding snap buttons and using gathering that facilitate breastfeeding and are suitable for the protrusion of the abdomen during the design phase. As it is known, newborn babies need to be breastfed frequently during the day. It can be challenging for mothers to constantly take off their clothes and put them back on during these breastfeeding times. The healing process of surgical wounds and stitches, espe-cially after cesarean delivery, is painful for mothers. At this stage, the sensitivity of surgical wounds and stitches can cause restrictions on mothers’ movements. A solution to this problem was provided by adding different func-tions to the models we designed in the collection that will allow breastfeeding by taking the chest part out. In one product, it was designed by sewing two separate pieces of fabric in layers so that it would open under the chest area. In another t-shirt product, snap buttons were added to the area under both arms so that the breast could be taken out when the snaps were opened. In the tank top models, snap drops were added to the middle of the chest area to facilitate access to the chest area. In order to support the products, care was taken to select the accesso-ries to be used in the product in a way that would contribute the most to the comfort of the product. Preferring snap 280 29–30 May 2025, Ljubljana, Slovenia buttons instead of classic buttons can be given as an example of accessory choices that increase comfort. Due to the high elastane content in the fabrics, the products are flexible and when the snaps are opened, it is aimed to stretch the t-shirt or tank top and bring the breasts out. Product details such as collar detail and sleeve length selection in the models are preferred in a way that supports comfort in the design. For instance, the reason why a double-breasted collar is preferred in the design of the dress model in sleepwear is to provide the mother with the convenience of exposing her breast during breastfeeding. In addition to the functions added considering the breastfeeding period, technical features have also been added for the growing of the abdomen during pregnancy. In our sleepwear t-shirt product, two separate pieces of fabric are sewn diagonally from the middle of the growing area of the abdomen and folds, providing a wide area for the abdomen. Thus, women who can wear this product in the first months of their pregnancy will be able to continue to wear it in the following months as the abdomen grows, as the folded fabric stretches and opens. Since the products are flexible, they can quickly return to the same form after being stretched. In this way, mothers will be able to continue using the product after the belly has gone down after birth. In this way, both the wear comfort features of the product have been increased and it has contributed to sustainability by adapting to the physical changes of a consumer in different periods. Another feature that can adapt to the expansion in the abdominal area is the adjustable elastic added to the abdominal part of the dress model. This elastic can be stretched and expanded or pulled and narrowed according to the size of the abdomen. At the same time, two layers of fabric were used in the chest area of the dress and snaps were added to the shoulder strap. In this way, the fabric left in the outer area can be opened. The chest parts of the fabric in the lower layer are left empty and breastfeeding can be done without having to take off the dress during breastfeeding moments. The studies on improving comfort and providing technical features in top wear products have been adapted to suit the bottom wear products. In order for the bottoms not to squeeze the abdominal area, gathers have been added to the sides of the products from both sides of the waist, and with this addition, it is aimed to shape according to the size of the abdomen. In this way, it is aimed to be a sustainable product that can be worn by the user in different periods, by adapting to the changing size of the abdomen both during pregnancy and postpartum, and to be a sustainable product that can be used for a long time. Figure 1: Sleepwear products 281 29–30 May 2025, Ljubljana, Slovenia Figure 2: Loungewear products 3. RESULT AND DISCUSSION The collection aims to increase the comfort of mothers during pregnancy and after birth by using different fabric types. In addition to increasing comfort with different fabric types in the products, it is aimed to increase user comfort by improving the functionality of the products with design differences. Clothing comfort is increased with details such as a double-breasted collar detail in the models. Thanks to the double-breasted collar product de-sign, the product provides ease of breastfeeding without taking it off, which saves the mother from the problem of putting it on and taking it off. In addition, the fabrics in the abdominal area offer the possibility of stretching, so the product can also be used after pregnancy. In the bottom clothing products, gathers are used so that it does not squeeze the growing belly, and a functional feature is added to increase the clothing comfort of the product. Table 1: Products and their composition Product Fabric Composition T-shirt Jersey 95% Viscose %5 Elastane T-shirt Jersey 80% Modal 20% Polyester Dress Pique 80% Modal 20% Polyester Bottom Jersey 80% Modal 20% Polyester Tank top Jersey 80% Modal 20% Polyester Nightdress Jersey 50% Cotton 50% Modal Nightdress Camisole 95% Viscose %5 Elastane Pyjamas set Jersey 50% Cotton 50% Modal Pyjamas set Camisole 95% Viscose %5 Elastane 282 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSION 4. CONCLUSION The main purpose of preparing this collection was to design products with increased functionality and comfort features by using fabrics and details that women can easily prefer during both pregnancy and postpartum periods The main purpose of preparing this collection was to design products with increased functionality and comfort and that will increase clothing comfort. Jersey fabric is soft and highly elastic, making it ideal for loungewear. features by using fabrics and details that women can easily prefer during both pregnancy and postpartum Pique fabric has a denser and slightly textured structure, providing a more structured look. Camisole fabric, on periods and that will increase clothing comfort. Jersey fabric is soft and highly elastic, making it ideal for the other hand, is thin and lightweight, commonly used in underwear. In terms of flexibility, viscose and elastane loungewear. Pique fabric has a denser and slightly textured structure, providing a more structured look. blends offer the highest stretchability. Modal and polyester blends provide both slight elasticity and durability. Cot-Camisole fabric, on the other hand, is thin and lightweight, commonly used in underwear . In terms of flexibility, ton and modal blends stand out for their breathability but have more limited elasticity compared to other blends. viscose and elastane blends offer the highest stretchability. Modal and polyester blends provide both slight Thanks to the different features added to the products, the chest area can be easily opened without having to elasticity and durability. Cotton and modal blends stand out for their breathability but have more limited completely remove the clothing during breastfeeding periods, and during pregnancy, the product can be stretched elasticity compared to other blends. Thanks to the different features added to the products, the chest area can and narrowed according to the protrusion of the abdomen and take shape according to the size of the abdomen. be easily opened without having to completely remove the clothing during breastfeeding periods, and during The desired softness and flexibility in the product structure is due to the natural fiber materials of the different fab pregnancy, the product can be stretched and narrowed according to the protrusion of the abdomen and take -rics used in the products. These technical functions added to the products are provided with both fabric selections, shape according to the size of the abdomen. The desired softness and flexibility in the product structure is due product design and auxiliary accessories. to the natural fiber materials of the different fabrics used in the products. These technical functions added to the products are provided with both fabric selections, product design and auxiliary accessories. Figure 3: Final products Figure 3: Final products 5. REFERENCES Visconti, F., Quaresima, P., Rania, E., Palumbo, A. R., Micieli, M., Zullo, F., ... & Di Carlo, C. (2020). Difficult caesarean section: A literature review. European Journal of Obstetrics & Gynecology and Reproductive Biology, 246, 72-78. Shamsaei, A., Kazemi, A., Enteshary-Najafabadi, H., & Borujeni, N. K. (2022). Essential criteria for designing healthy maternity wear: A 4 narrative review. Iranian Journal of Nursing and Midwifery Research, 27(6), 492-495. 283 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Öykü Elmas Ekin Üstem DAGİ DAGİ 34380, Şişli/İstanbul, Türkiye 34380, Şişli/İstanbul, Türkiye +90 532 325 90 34 19 Mayis, Birahane Sk. No:3/1 19 Mayis, Birahane Sk. No:3/1 +90 507 660 29 11 ekin.ustem@dagi.com.tr oyku.elmas@dagi.com.tr Ecem Alagöz DAGİ 19 Mayis, Birahane Sk. No:3/1 34380, Şişli/İstanbul, Türkiye +90 530 068 81 89 ecem.alagoz@dagi.com.tr 284 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION DESIGN OF A SLEEPWEAR COLLECTION WITH COOLING EFFECT Ecem Alagöz1, İsmet Ege Kalkan2 and Umut Kivanç Şahin2 1DAGİ Design Center, Turkey 2 İstanbul Technical University, Department of Textile Engineering, Turkey Abstract: With increasing global temperatures and evolving consumer expectations, cooling textiles have gained significance, especially in sleepwear where thermal comfort is essential. This study aims to evaluate the perfor-mance of four knitted fabrics incorporating various fiber compositions and cooling finishes. The fabrics—based on modal and lyocell blends—underwent different finishing treatments, including collagen-based, silicone-based, and hydrocool technologies. Standardized testing (ISO 11092, ISO 9237, Alambeta, and ISO 13938-1) assessed thermal conductivity, thermal resistance, air permeability, moisture permeability, and bursting strength. Results showed that the silicone-treated fabric offered superior cooling but had low durability, while the hydrocool-treated fabric achieved a balanced performance, making it suitable for functional sleepwear applications. Keywords: cooling effect, thermal resistance, moisture management, breathable textiles, functional finishing, eco-friendly fibers 1. INTRODUCTION With technological developments and evolving consumer expectations, textiles are no longer limited to providing basic protection but have evolved into smart and multifunctional materials. A major area of innovation in textile technology is thermal regulation, particularly for personal cooling applications because the increasing global tem-peratures and the discomfort caused by excessive heat have led to a rising demand for textiles that can efficiently dissipate heat, wick moisture, and provide a cooling effect (Jing, 2024). There are different methods to obtain cooling-effect fabrics which are: • Moisture-wicking technology: Fibers designed to absorb and quickly evaporate sweat. • Phase Change Materials (PCMs): Microencapsulated compounds that absorb and release heat as they transition between solid and liquid states. • Cooling finishes and additives: Specialized treatments, including hydrophilic coatings, collagen-based technology, and silicone-based „ice-feeling“ finishes, which create a cooling sensation upon skin contact (Tarai, 2024; Gulrajani, 2011). In addition to these methods, cooling can be obtained with the fabric structure. Open-knit structures or speciali-zed weaves that enhance airflow and heat dissipation. Modal and lyocell fibers are widely used in cooling textiles due to their high moisture absorption, soft texture, and breathability. Modal has excellent moisture management and softness. However, lyocell is considered a more sustainable alternative with enhanced moisture-wicking and air permeability properties (Özdemir, 2017). This study investigates different finishing technologies applied to modal and lyocell-based fabrics to enhance cooling properties. To evaluate the cooling performance, the selected fabrics were tested using standardized methods, including Permatest ISO 11092 (thermal resistance and moisture permeability), Alambeta (thermal conductivity and heat retention), ISO 9237 (air permeability) and bursting strength. According to the test results, the best fabric compo-sition and finishing technique for cooling sleepwear applications are determined. 285 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL In this study we have selected 4 different types of fabric. Each fabric that is used in this study has different com-position and finishing techniques. The fabrics are tested to see which properties show better cooling properties. The fabric properties and compositions are listed below: Table 1: Code, composition, knit structure and cooling technology of the fabrics. Fabric Code Fabric Composition Knit structure Cooling Technology Fabric 1 50% Cotton - 50% Modal Single Jersey No cooling effect (control fabric) Fabric 2 74% Modal - 26% Polyamide Single Jersey Collagen-based cooling technology Fabric 3 94% Modal - 6% Elastane Single Jersey “Ice-feeling” silicone additive Fabric 4 95% Lyocell - 5% Elastane Single Jersey Hydrocool finishing technology Finishing Techniques: 1. Collagen-Based Cooling Technology (Fabric 2): Collagen-infused treatments enhance moisture reten- tion and provide a cooling sensation by increasing surface hydration (Huang, 2018). 2. Ice-Feeling Silicone Additive (Fabric 3): A thermoregulating finish containing eco-friendly silicone oil, creating a long-lasting cooling effect upon skin contact (Silibase Silicone, 2025). 3. Hydrocool Finishing Technology (Fabric 4): A moisture-management treatment that enhances the ca- pillary action of lyocell, ensuring rapid sweat evaporation and increased breathability (Rudolf, 2025). Testing Methods and Standards: • Permatest (ISO 11092): Measures water vapor resistance and moisture permeability. • Alambeta Test: Evaluates fabric thermal conductivity and heat retention properties. • Air Permeability (ISO 9237): Assesses the breathability of fabrics by measuring air passage through the material. • Bursting Strength (ISO 13938-1): Measures the capacity of the fabric to pressure. 3. RESULTS Table 2: Test results of the fabrics. Fabric Code La(mW/m.K) r(mK/W.m2) Fabric 1 30.4 9.4 Fabric 2 33.9 19.8 Fabric 3 18.2 15.4 Fabric 4 38.1 10.2 286 29–30 May 2025, Ljubljana, Slovenia Table 3: Air water vapor permeability test results of the fabrics. Fabric Code Permeability(Pa.m2.W-1) Fabric 1 2.5 Fabric 2 3 Fabric 3 3.5 Fabric 4 3.8 Table 4: Air permeability test results of the fabrics. Fabric Code P(mm/s) Fabric 1 1065.9 Fabric 2 1653.4 Fabric 3 1818.5 Fabric 4 1504.5 Table 5: Bursting strength test results of the fabrics. Fabric Code Bursting Strength(N) Fabric 1 127.89 Fabric 2 148.47 Fabric 3 93.59 Fabric 4 131.81 4. DISCUSSION The cooling and durability properties of the four fabrics were analyzed using standardized test methods. Fabric 1, the control sample without a cooling finish, showed baseline thermal resistance (9.4 mK/W·m²) and moderate conductivity (30.4 mW/m·K), along with the lowest moisture and air permeability. These values reflect its limited effectiveness in promoting thermal comfort. Fabric 2, treated with a collagen-based finish, offered improved resistance (19.8 mK/W·m²) and the highest bursting strength (148.47 N), indicating excellent durability. However, its moderate air and moisture permeability slightly limited its cooling potential. Fabric 3, incorporating an “ice-feeling” silicone additive, demonstrated the highest air permeability (1818.5 mm/s) and lowest conductivity (18.2 mW/m·K), indicating excellent cooling ability. However, its bursting strength (93.59 N) was the lowest, highlighting a trade-off between breathability and structural integrity. Fabric 4, finished with Hydrocool technology, balanced strong performance across all parameters. With the highest water vapor permeability (3.8 Pa·m²/W), good air permeability (1504.5 mm/s), and moderate mechanical strength (131.81 N), it stands out as the most practical option for long-term, wearable applications. 5. CONCLUSIONS The results underscore the importance of thermal resistance over conductivity when assessing fabric insulation. The study also emphasizes that fabric finishes significantly influence both comfort and durability—two often com-peting priorities in textile design. 287 29–30 May 2025, Ljubljana, Slovenia 6. REFERENCES Gulrajani, M. L., Gupta, D. 2011. “Emerging techniques for functional finishing of textiles.” Indian Journal of Fibre & Textile Research, 36(4), 388–397. Huang, C.-L., Fu, J.-Y. and Cheng, K.-Y. 2018. “Development of Woven Fabrics with High-Count and Cooling Collagen.” Trends in Textile & Fashion Design 3(2): 299–301. Jing, Y., Du, M., Zhang, P., Liang, Z., Du, Y., Yao, L., Chen, H., Zhang, T. and Zhang, K. 2024. “Advanced Cooling Textile Technologies for Personal Thermoregulation.” Materials Today Physics 41: 101334. Özdemir, H. 2017. “Permeability and Wicking Properties of Modal and Lyocell Woven Fabrics Used for Clothing.” Journal of Engineered Fibers and Fabrics 12(1): 12–21. Rudolf. 2025. Sustainable Solutions for Moisture Management. URL: https://www.textiletechnology.net/news/news/rudolf-sustainable-solutions-for-moisture-management-35271 (last accessed on 30. 01. 2025). Silibase Silicone. n.d. Universal Ice Feeling Silicone Oil: Textile Softener Auxiliaries for Textiles. URL: https://www.silibasesilicone.com/ silicone-softener-auxiliaries-for-textiles/ice-feeling-silicone-oil/universal-ice-feeling-silicone-oil.html (last accessed on 23. 04. 2025). Tarai, M., Yadav, S. 2024. “Advances in textile finishing.” International Journal for Research Trends and Innovation 9(4): 26–32. Vivcharyuk, O. 2023. “Cooling Garment Design for Women: From Fibre to Fit.” PhD diss., Toronto Metropolitan University. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Ecem Alagöz İsmet Ege Kalkan DAGİ Design Center İstanbul Technical University 19 Mayis, Birahane Sk. Department of Textile Engineering, No:3/1, Koç Plaza Gümüşsuyu, İnönü Cd. No:65 34380, Şişli/İstanbul, Türkiye 34437 Beyoğlu/İstanbul 34421, Istanbul, Türkiye +90 530 068 81 89 +90 532 395 43 87 ecem.alagoz@dagi.com.tr kalkani15@itu.edu.tr Umut Kivanç Şahi̇n İstanbul Technical University Department of Textile Engineering Gümüşsuyu, İnönü Cd. No:65 34437 Beyoğlu/İstanbul 34421, Istanbul, Türkiye +90 532 585 87 07 sahinumut3@itu.edu.tr 288 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION USE OF JAPANESE KNOTWEED IN WOVEN TEXTILES Kristi Komel1 and Katja Burger Kovič1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The project titled Use of Japanese knotweed in woven textiles explores the utilization of an invasive plant in textile applications in connection with the idea of regenerative design. The issue of invasive plant prolifer-ation and the lack of constructive approaches to limit their excessive growth are highlighted. Solutions are sought in regenerative design, which goes beyond sustainable approaches by repairing negative consequences and taking a holistic view of the problem. The experimental part begins with the presentation of making paper yarn from locally sourced Japanese knotweed paper. It then discusses the use of dye and explores textile weaving techniques and post-processing of the resulting fabrics. The result is the presentation of a collection of fabrics that not only includes paper made from Japanese knotweed, but also dye derived from its roots and wood obtained from its stems. Keywords: weaving, paper yarn, Japanese knotweed, regenerative design 1. INTRODUCTION Non-native plant species, unlike native ones, have been intentionally or unintentionally introduced into the environment by humans (GOV.SI, 2009). They typically establish themselves in degraded areas such as lands depleted by intensive agriculture, abandoned construction sites, and waste disposal areas (Paradiž, 2012). Through rapid spreading and consequent occupation of space, they can negatively affect the growth of native plants and disrupt the ecosystem in which they are found (Vrabič-Brodnjak & Možina, 2022). One of the most prevalent invasive non-native plants in our region is Japanese knotweed. Its rapid growth and spread are most often controlled through removal, which generates large quantities of biodegradable waste that must be handled carefully to prevent further spread (Frajman, 2008). At the same time, we live in an era where the search for new, environmentally friendly material sources is increasingly important, enabling sustainable and circular economies. The waste from removed invasive plants could provide a solution, as it represents an abundant natural resource that can be repurposed for various uses. The textile industry is one of the largest global polluters and resource consumers. Sustainable design practices are one approach to reducing the negative impact of the textile industry on the natural and social environment. However, this approach does not address the damage already done. Regenerative design takes this concept further, offering a promising method to introduce new materials, such as invasive plants, into existing design processes. The regenerative approach takes a step further than sustainability; whereas sustainability focuses on preserving a certain state with minimal or no impact, the regenerative approach strives to enhance and improve the current condition (Tate + Co, 2023). One way to use invasive plants in textiles is through paper, which has a long history as a textile material, particularly in Eastern civilizations (Leitner, 2005). This study presents the use of paper to create yarn, which is then woven into a collection of handwoven pieces. 289 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL Material Research I began the project by researching Japanese knotweed and exploring which parts of the plant could be utilized, from paper made from its cellulose to its wood and rhizomes. My aim was to incorporate as much of the plant as possible into my textiles. I harvested the plant parts in close proximity to my home, on the edge of the forest beneath Rožnik hill in Ljubljana. As with the collection of any invasive plant, I had to be careful to avoid unintentionally spreading the plant to new locations through careless harvesting or handling of its rhizomes. Preparation of Paper Yarn To make the paper yarn, I used Notweed paper made from Japanese knotweed, created by the Trajna col-lective. I worked with paper from two different series. The first, from 2021, was darker in colour and consisted of 50% knotweed cellulose and 50% wood cellulose. The second series, from 2023, was lighter in colour and made of 50% knotweed cellulose, 45% wood cellulose, and 5% waste paper. I began making the yarn by cutting the paper into strips of different widths. I ultimately chose a strip width of 5 millimeters, as it provided the best results; the yarn wound smoothly and did not tear excessively. I cut the paper using a laser cutter, ensuring not to cut it all the way to the edge, leaving a 1-centimeter margin. Then, using scissors, I cut through to the edge on every other strip, creating a continuous strip. The paper was moistened with water using a spray bottle, as the spinning process is much easier when the strips are damp. I then twisted the strips into yarn using a hand spindle (Figure 1). The yarn was left to dry and then I wound it into a skein us-ing a yarn winder. Figure 1: Paper yarn spinning (foto: Tjaša Bavcon). Dye Dye can be extracted from various parts of the Japanese knotweed plant. Since I started the project during the colder part of the year, I only had access to its rhizomes. I experimented with how the dye changes when the pH level is altered. The dye extract, obtained by boiling dried knotweed rhizomes in distilled water, was divided into two containers. To one, I added white vinegar, and to the other, washing soda. Paper absorbs dye without requiring special pre-treatments or post-treatments necessary for dyeing textile fibers. This allowed me to experiment with different methods of applying dye to the paper yarn. During testing, I applied the dye to both the warp and the weft, evaluating which method was more suitable. Ultimately, I decided on a dyeing process that involved directly applying the dye to the wound yarn spool, resulting in a gradient-colored 290 29–30 May 2025, Ljubljana, Slovenia fabric (Figure 2). Along with dyeing the weft yarns, I also experimented with dyeing the warp yarns. This created vertical color stripes to complement the horizontal ones produced by the dyed weft yarns. Figure 2: Dyeing a skein of paper yarn (photo: Tjaša Bavcon). Wood While exploring all the possibilities for using Japanese knotweed in textiles, I also experimented with the use of its woody parts. The woody stems were first soaked in water, then split lengthwise and spread apart, resulting in a thin, veneer-like material. During the research, several small woven pieces made from knotweed wood were created, and in the final collection, it was used as an element for hanging the fabrics. Weaving Before setting up the loom, I created a plan and prepared a complete pattern (Figure 3): • Warp: paper yarn – Nm 1.65 / tex 625 (Lankava thin paper yarn) • Weft: handmade paper yarn – Nm 1.4 / tex 713 • Threading: straight draw in 8 shafts • Thread density in the reed: 1 thread/cm • Warp width: 50 cm • Warp length: 6 threads/cm 291 29–30 May 2025, Ljubljana, Slovenia Figure 3: weaving draft for waffle weave. After completing the process of setting up the loom, I began weaving samples. To make the weaving process easier, I sprayed water onto the yarn, which also increased the thread density and resulted in a denser fabric. The fabric in the left photograph was woven with a dry warp and dry weft, while the fabric in the right photograph was woven with both the warp and weft moistened with water (Figure 4). Figure 4: Comparison of fabric in waffle weave; in the left image, the warp and weft threads were not moistened during weaving, unlike the threads in the fabric on the right. I was able to shape the paper fabric while it was wet, and it retained that shape after drying. In this way, I at-tempted to model three-dimensional forms from the woven surface. I also worked to create spatial shapes by weaving double fabrics, which were later modeled while wet. Development of the fabric collection Inspired by the trials I had previously woven, I created a collection of woven textile pieces. (Figure 5). I tried to incorporate different technicques, use of color and shaping of the fabrics to get a diverse collection. 292 29–30 May 2025, Ljubljana, Slovenia Figure 5: collection of paper yarn weavings (foto: Kristjan Jarni). 3. RESULTS Inspired by the trials I had previously woven, I created a collection of woven textile pieces. Some pieces are part of diptychs or triptychs. All share the same warp and weft material, with some featuring added colour, while others emphasize the shaping of the woven material into forms. The result is a collection of fabrics made from handmade yarn produced from Japanese knotweed paper. Alongside the cellulose-based paper from this widespread invasi-ve plant, a dye derived from its rhizomes was also used. Some smaller experiments were carried out using wood from the stems, but in the final collection, these were included solely as supports for hanging the textiles. The fabrics showcase various possibilities of weaving with paper yarn and incorporating the dye, each of them capable of serving as a standalone decorative piece or in combination with other textiles from the collection. 4. DISCUSSION Japanese knotweed is among the most invasive species in the world. With its rapid spread and consequent occupation of space, it can negatively impact the growth of native plants and affect the ecosystem in which it is found. This project demonstrates the use of locally produced paper from Japanese knotweed to create yarn, which is then woven into a collection of textile pieces. The choice of paper as the sole material used in the fabrics follows the principle of monomateriality. My aim was to create an environmentally friendly collection that not only addresses sustainability but tries to actively engage in ecological regeneration. Due to the characteristics of the handmade yarn, which is relatively fragile, the range of applications is somewhat limited, particularly for products exposed to daily contact with other surfaces or the body. On the other hand, the use of paper allows for the crea-tion of fabrics that transcend the two-dimensionality of more conventional textile materials, giving them a stronger spatial presence. For this reason, the fabrics could be integrated into interiors as architectural elements, such as partition walls, directly referencing the historical use of paper in house construction and spatial division. A unique feature of paper fabrics is their ability to be shaped while wet into a chosen form, which they retain once dried. Fabrics arranged in triptychs with cylindrical shapes could, for instance, be transformed into lighting elements by adding light components. 293 29–30 May 2025, Ljubljana, Slovenia 5. CONCLUSION The project explores various possibilities for utilizing Japanese knotweed for textile purposes. The aim of the project was to address the problem of biodiversity decline and the spread of invasive species while searching for alternative material sources for textile making. By demonstrating how invasive species can be repurposed into sustainable textiles, this project highlights the potential for design to contribute to ecological regeneration and inspire new approaches to sustainable material sourcing. 6. REFERENCES Frajman, B. Japonski dresnik Fallopia japonica, Informativni list 1. (2008). In: Tujerodne vrste. Available from: https://www.tujerodne-vrste. info/wp-content/uploads/2018/05/INF1-japonski-dresnik.pdf [6. February 2024]. GOV.SI. Invazivne tujerodne vrste rastlin in živali. Available from: https://www.gov.si/teme/invazivne-tujerodne-vrste-rastlin-in-zivali/ [17. January 2024]. Leitner, C. (2005). Papier Textilien : Geschichte, Materialien, Experimente. 1. edition. Bern: Haupt Verlag, pp. 35. Paradiž, J. (2012) Tujerodne rastlinske vrste in ugotavljanje območja njihove razširjenosti v krajinskem parku ljubljansko barje : Končno poročilo o rezultatih preiskovanja invazivne kanadske zlate rozge, japonskega dresnika in žlezave nedotike v vzhodnem delu Krajinskega parka Ljubljansko barje. Available from: https://www.ljubljanskobarje.si/wp-content/uploads/2021/06/koncno-porocilo_Paradiz_KP-2012.pdf [4. February 2024]. Tate + Co. (2023) What is regenerative design? Available from: https://tateandco.com/answers/what-is-regenerative-design/ [29. February 2024]. Vrabič-Brodnjak, U. & Možina, K. (2022) Invasive alien plant species for use in paper and packaging materials. Fibers, vol. 10, no. 11, str. 2. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author: Kristi Komel Katja Burger Kovič and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška ulica 5 Snežniška ulica 5 1000 Ljubljana 1000 Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana katja.burgerkovic@ntf.uni-lj.si 040 134 677 komel.kristi@gmail.com 294 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION BAUHUS INSPIRED HOME TEXTILES AND CARDBOARD MODULAR FURNITURE FOR CHILDREN Tasja Videmšek1 and Katja Burger Kovič1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The paper explores the development of surface patterns and modular cardboard furniture for children, encouraging free and creative play. The theoretical part presents key principles of children’s design, the impor-tance of modularity, and the role of colours, shapes, and patterns in children’s perception and development. It also examines the influence of Bauhaus, particularly its learning-through-play approach and the “Vorkurs” foundation course. The experimental part introduces the development of illustrated characters inspired by Oskar Schlem-mer’s costumes, transformed into graphic patterns and textile or cardboard objects for children’s interiors. Addi-tionally, it presents the development of modular cardboard furniture, exploring various assembly methods and the integration of textile elements to create contrasting surfaces with added tactile and aesthetic value. Keywords: surface pattern design, home textiles, modular design, cardboard furniture, children’s interior. 1. INTRODUCTION Toys and objects surrounding a child play a crucial role in their development, particularly through play, which encourages their cognitive, emotional, social, and motor growth. In contemporary design for children’s products the emphasis is on innovation, sustainable materials, and aesthetic appeal. Parents are increasingly interested in thoughtfully designed products that encourage child’s creativity and provide long-term usability (Appleton 2018; Birks 2018). Designing for children has evolved alongside changes in society, technology, and pedagogy. At the end of the 19th and the beginning of the 20th century, educational theories highlighted the importance of open-ended play and child-friendly learning environments, influencing the development of products tailored to children’s needs. Modernism introduced lightweight and practical materials into design, simplifying use, cleaning, and maintenance of the products. Between the 1950s and 1970s, plastic became the dominant material due to its durability and low production costs. Today, designers prioritize sustainable materials such as cardboard, wood, and EPP foam. These materials enable the creation of functional, safe, and modular products that grow with the child while en-couraging free play and exploration. Throughout history, cardboard has proven to be an exceptionally popular material because it is lightweight, recyclable, easy to shape, and sustainable. These qualities make it ideal for creating furniture and toys that stimulate children’s creativity (Appleton 2018; Birks 2018). Modularity is one of the key concepts in children’s design, providing flexibility, sustainability, and multifunctionality. Construction toys based on modularity allow children to engage in unlimited creation while developing spatial understanding, motor skills, and imagination. Additionally, the visual appeal of a product – its shape, colours, textures, and patterns – plays a pivotal role in establishing interaction between the child and the object (Bilham 2022; Reynolds 2023). The Bauhaus artistic movement (1919–1933) had a significant influence on design for children, blending art, technology, and craftsmanship. The movement championed simplicity, functionality, the use of authentic mate-rials, and encouraged experimentation through play. A leading designer in children’s products during this period 295 29–30 May 2025, Ljubljana, Slovenia was Alma Siedhoff-Buscher, who created iconic Bauhaus toys and modular furniture that encouraged children’s creativity and exploration (Droste 2023; Kinchin and O’Connor, 2012). The research focuses on the field of design for children and its principles, the importance of modularity in chil-dren’s products and the role of colours, shapes and patterns in children’s perception of the world and their holistic development. The aim of the research was the development of surface pattern designs and modular cardboard furniture for children that invite them to explore their environment and encourage free and creative play. 2. EXPERIMENTAL The focus of the experimental part of the research was on the Bauhaus theories of learning and creating through play, following the exercises of the so-called “Vorkurs”, or preliminary course that was taught at the school. This section presents the development of playful, illustrated characters inspired by Oskar Schlemmer’s costumes for the “Triadic Ballet”, embodying the Bauhaus preference for primary colours and geometric shapes. By assembling forms from basic shapes such as circles, squares, triangles, squiggles, zigzags, spirals, a chequerboard pattern, etc., a group of playful graphic figures was created. The colour palette consists of a minimal number of contrasting colours, which was maintained throughout the collection. Figure 1: Colour palette and character design (from sketch to final digital illustration) (Source: the author) The characters were then grouped into all-over patterns. Due to their simplicity, the characters were also easily transformed from flat digital illustration into new spatial forms. Digital printing was used to transfer the patterns onto different types of textiles. Certain products were also embellished with hand embroidery, while products made of cardboard were produced using laser cutting technology and digital printing on cardboard. The second part of the experimental research presents the development of modular cardboard furniture. It shows methods of assembling modules into abstract and functional forms and integrating other materials into spatial constructions in the form of improvised or textile modules. Cardboard was chosen as the main material, as its properties make it a very suitable material for making products for children. It is light, strong and 100% recyclable and, above all, safe for children to use. The plain cardboard also attracts and allows children to freely explore and personalise their creations. Through spontaneous experimentation of assembling different forms of modular constructions, flat modules that can be joined together with notches proved to have the greatest potential. This type of module production is much simpler and faster, and the material consumption is also much lower. It was also studied where the notches should best be placed to have as many possibilities as possible to create different forms, both functional and completely abstract. 296 29–30 May 2025, Ljubljana, Slovenia The basic structure that led to the design of the remaining modules was a child’s chair that can be connected to other structures or transformed into other forms of shelters, toys and furniture. Based on the grid, the final shapes of the geometrically simple and refined modules were designed, all with rounded corners for children’s safety. The final form of the construction set prototype in a scale of 1:1 was created in collaboration with the Pulp and Paper Institute (ICP) in Ljubljana. Figure 2: Modular construction set in vector form (Source: the author) The study of contrasts and materials based on Itten’s Vorkurs led to researching the relationship between textiles and cardboard. To this end, some modules were given perforated surfaces to serve as embroidery walls, with the aim of encouraging the development of children’s motor and manual skills as well as providing additional uplifting and softening of the hard cardboard. Figure 3: The study of contrasts between soft and hard modules (Source: the author) 297 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS WITH DISCUSSION The final products include a collection of playful illustrated characters assembled into all-over patterns for print or transformed into other forms of textile and cardboard objects for children’s interiors, such as cardboard lamps and toys, patterned pillows and hand embroidered dolls. Moreover, a cardboard modular system was developed. Due to its composability and interactivity, the modules can be easily transformed into various furniture or playing constructions. Textile worms made from scrap fabric can be inserted and woven into the perforated mesh of the cardboard modules, creating new contrasting surfaces with additional tactile and aesthetic values. Cardboard surfaces can also be scribbled on, painted and covered with stickers. The work focuses on designing simple and accessible products for children that encourage play, creativity, and holistic development. It is important to recognize that designing for children is a complex process, as it requires adhering to numerous principles and quality standards that determine when a product can enter the market. The products presented in this work are prototypes, offering significant potential for further development. A collection of products was created that can adapt to various children’s needs, avoiding focusing on any specific age group. Textile products, due to their softness and sensory qualities, are suitable even for the youngest chil-dren. Meanwhile, the construction set is more appropriate for children aged 4 and above, as it aligns with their more advanced motor skills and ability to tackle various challenges. The construction set is also well-suited for groups of children, as it promotes group collaboration and collective problem-solving. Figure 4: Textile and cardboard products for children’s interior (Source: the author) Figure 5: Cardboard modular construction with textile worms (Source: the author) 298 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS In designing for children, it is essential to incorporate not only functional and aesthetic principles but also sustain-able and advanced solutions, focusing on integrating concepts of circular design. Emphasizing the principles of modularity and multifunctionality is equally important, as they are key to creating flexible and long-lasting products that can adapt to the diverse needs of children and their environment. Through research and experimentation different products have been created. They are appealing to children and encourage them to play, while also resonate with adults who value colour, playfulness, and joy in their homes. By studying children’s culture and de-veloping modular and textile products, I have laid the groundwork for further exploration in the fields of children’s design, illustration, and textile creation. 5. REFERENCES Appleton, L. 2018. “Design for children matters”. In Design for children: play, ride, learn, eat, create, sit, sleep, edited by Kimberlie Birks, 4–6. New York: Phaidon Press. Birks, K. 2018. Design for children: play, ride, learn, eat, create, sit, sleep. New York: Phaidon Press. Bilham, Jasmine. 8 things to consider when designing for children. URL: https://raw.studio/blog/designing-for-children (last accessed: 30. 1. 2025). Droste, M. 2023. Bauhaus: 1919–1933. Köln: Taschen. Kinchin, J., O’Connor, A. 2012. Century of the child: growing by design 1900–2000. New York: Museum of Modern Art. Reynolds, Oliver. Building Blocks: The Importance of Construction Toys for Child Development. URL: https://reynoldsoliver.medium.com/ building-blocks-the-importance-of-construction-toys-for-child-evelopment-38f96eadabfd (last accessed: 30. 1. 2025). ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Tasja Videmšek Katja Burger Kovič and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška ulica 5 Snežniška ulica 5 Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia katja.burgerkovic@ntf.uni-lj.si tasja.videmsekdesign@gmail.com 299 TEXTILE EDUCATION 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION SERVICE LEARNING IN TEXTILE, CLOTHING AND FASHION EDUCATION Alenka Pavko Čuden1, Barbara Simončič1, Brigita Tomšič1, Klara Kostajnšek1 1 and Matejka Bizjak 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Service learning is an educational approach that combines academic learning with community ser-vice. It expands students‘ knowledge by engaging them in real-world projects that address community needs. Unlike volunteering, charity work, community service, internships or field education, service learning integrates structured reflection and coursework so that both sides, students and communities, benefit. It is used in a variety of settings, including education, healthcare and business, and promotes civic engagement, critical thinking and social responsibility. In the textiles and fashion industry, service learning can include sustainable clothing projects, community-based textile recycling or working with marginalised artisans. Students gain hands-on experience while addressing the environmental and ethical challenges of the industry. The paper provides a comprehensive overview of the foundations, the development of the service learning concept and its potential in the fields of tex-tiles, clothing and fashion as well as the associated challenges. Keywords: service learning, community service, textiles, clothing, fashion, sustainability. 1. INTRODUCTION: SERVICE CONCEPTS Service learning is an educational concept that is often associated or even (mis)interpreted with terms such as volunteering, charity, community service, internship or field education, as it contains elements of all these activi-ties. Volunteering is the engagement of students in activities where the focus is on the service provided and the primary beneficiary is clearly the recipient of the service. Volunteers are people who perform a service or good deed of their own free will and without payment. Charity is the voluntary giving of help, typically in the form of money, goods or services, to those in need. It is driven by compassion and aims to improve the well-being of individuals or communities in need. Charitable actions can be carried out by individuals, organisations or institu-tions and often involve humanitarian aid, social services and philanthropic initiatives. Community service is the engagement of students in activities that focus primarily on the service provided and the benefit of the activities to the recipients. Students benefit by learning more about how their service makes a difference in the lives of service recipients. Internship programmes engage students in service primarily for the purpose of providing them with practical experience that enhances their learning or understanding of topics relevant to a particular field of study. Field education programmes provide students with extracurricular service opportunities that are connected to, but not fully integrated with, their formal academic studies. Students perform service as part of a programme that is primarily designed to enhance students‘ understanding of a particular field of study, although the service perfor-med also plays an important role (Furco, 1996; Oxford English Dictionary, n.d.). Service learning is an innovative educational approach that combines academic teaching with social engage-ment. By emphasising the application of knowledge in the real-world, it enhances both the learning experience and the impact on society. Unlike a field education programme, where service is performed in addition to students‘ coursework, a service learning programme integrates service into the course(s). 301 29–30 May 2025, Ljubljana, Slovenia 2. THEORETICAL FRAMEWORK 2.1 Experiential learning Learning methods are evolving alongside the need to improve the quality and effectiveness of the teaching and learning process, with three components interlinked in learning activities: teachers, students and the learning environment (Rahmi, 2024). One approach that is receiving more and more attention is experiential learning (EL). This method was first introduced by David A. Kolb in 1984 and has since become one of the most influential learn-ing models in contemporary education. The theory of experiential learning is based on the idea that knowledge is acquired through experience. Kolb introduces the experiential learning cycle, which consists of four phases (Figure 1): - concrete experience (CE) – engaging in a new experience or situation,- reflective observation (RO) – observing and reflecting on the experience,- abstract conceptualization (AC) – developing theories or concepts from reflection,- active experimentation (AE) – applying learned concepts to test ideas in practice. Figure 1: Kolb’s learning cycle (adapted from Kolb, 1984) The approach aims to combine theory with practise so that students not only understand the concepts theoreti-cally, but can also apply them in real-life situations. Each of these phases is interlinked and forms a continuous learning cycle. Kolb’s model emphasises the importance of personal involvement in learning rather than passive absorption of information and highlights how experiential learning impacts education, professional development and lifelong learning. Kolb also argues that learning is a continuous process that is shaped by individual experi-ences and environments and influences personal growth and skill development (Kolb, 1984). 2.2 Service learning Service learning is an experiential learning pedagogy that empowers students beyond the classroom to actively engage in their learning and develop civic knowledge and skills. Through service learning, students have the opportunity to apply the knowledge and skills they have gained in the classroom to real-world community needs. This hands-on, experiential learning not only reinforces academic concepts, but also promotes the development of the whole person. 302 29–30 May 2025, Ljubljana, Slovenia The concept of service learning (SL) has evolved over the years and can be traced back to the broader principles of experiential education. Originally, SL in the broadest sense of the word focused primarily on volunteering and community service, emphasising the service component over academic learning. This approach often manifested itself in an informal setting, such as campus organisations or community clubs, where students engaged in service activities without structured educational goals (Furco, 1996). Nonetheless, the historical development of SL in education reflects broader societal changes and evolving pedagogical theories. While early service learning efforts were often associated with moral and civic engagement, contemporary models increasingly focus on knowledge of community needs, critical thinking, problem solving, self-awareness, and communication skills as central educational goals (Kennedy, 2023). The emphasis on these skills is particularly relevant in the context of textiles, clothing and fashion education, where the need for innovative, sustainable practises to address global challenges is paramount. Service learning programs are distinguished from other approaches to experiential education by their intention to equally benefit the provider and the recipient of the service as well as to ensure equal focus on both the service being provided and the learning that is occurring. Figure 2: Distinction among service concepts/programs (adapted from Jacoby,1996) Therefore, service learning is a form of education in which students participate in organised activities designed to meet human and community needs, along with structured opportunities for reflection aimed at achieving desired learning outcomes, including a better understanding of course content, a broader appreciation of the discipline, and a stronger sense of civic responsibility (Jacoby, 1996; Bringle, 1996). Service learning aims to balance student learning with community outcomes. Rather than charity, service-learning emphasises reciprocity (Furco, 1996). 2.3 Service learning potential in textile, clothing and fashion education Service learning offers significant potential in the textile, clothing and fashion industry by bridging academic knowledge with real-world applications. Through hands-on projects that address social and environmental chal-lenges, students gain practical experience while contributing to meaningful change: - Sustainability and ethical fashion – Service learning can include projects such as textile recycling initia- tives, upcycling programmes and sustainable fashion campaigns. Students can collaborate with local communities to reduce textile waste and promote ethical consumption, organise clothing swaps and sus-tainable fashion shows, etc. - Community engagement and empowerment – Working with non-profit organisations, marginalised arti- sans, underprivileged communities or local cooperatives allows students to apply design, production and business skills while supporting traditional craftsmanship and fair labour practises. - Industry collaboration and innovation – Service learning can foster partnerships between universities, textile, clothing and fashion brands and non-profit organisations and support innovative problem solving in areas such as waste management, circular fashion, smart textiles and sustainable material sourcing. 303 29–30 May 2025, Ljubljana, Slovenia - Education and awareness – Students can participate in awareness-raising campaigns about ethical fash- ion choices, responsible consumer behaviour and environmental impact, strengthening their role as fu-ture industry leaders with a strong attitude towards social responsibility. By integrating service learning into textile and fashion education, students not only refine their technical and creative skills, but also develop a deeper understanding of ethical and sustainable practises, preparing them for socially responsible careers (Black, 2012; Kolb, 1984; Fletcher, 2016). 2.4 Service learning challenges in higer education Integrating the concept of service learning into the curriculum can pose significant challenges that can stand in the way of effective implementation in educational institutions. One major obstacle is often a lack of time. Teachers are often busy with curricula, leaving little opportunity to incorporate service learning activities that require addi-tional planning and commitment. When these time constraints are coupled with traditional assessment schedules, they can lead to superficial engagement rather than deep learning experiences. Teachers often find it difficult to incorporate aspects of reflection and community interaction into their lesson plans. Another major challenge is the limited resources. Implementing service learning requires access to community partners, funding for projects, and training for teachers and their assistants to facilitate these experiences. Edu-cational institutions often face budget constraints that limit funding for projects, training and materials needed for effective implementation. Without sufficient funding, teachers may struggle to develop meaningful service learning opportunities. In addition, building collaborations with local organisations requires time and effort, both of which can be in short supply for busy teachers. This reliance on external partners can lead to inconsistent project de-livery and lower student engagement. In addition to financial and partnership challenges, resources can also be limited by a lack of staff. The lack of trained staff can affect the quality of service learning experiences, ultimately impacting student outcomes and the development of their social responsibility. To effectively overcome these resource constraints, institutions must prioritise strategic partnerships and seek al-ternative funding opportunities. Establishing clear goals is fundamental to effective integration of service learning. Involving students in defining these goals encourages student ownership and engagement. In addition, alignment with academic standards can present difficulties. Educators must ensure that service learn-ing projects complement existing curriculum requirements while meeting educational goals. This balancing act is important to maintain academic rigour while providing experiential learning opportunities. 3. SERVICE LEARNING IN SLOVENIA 3.1 Publications and projects The fundamental problem in exploring the areas of service learning in Slovenia is the inconsistency of Slovenian terminology, as various more or less appropriate translations are used to describe the concept of service learning, which also include the broader area of socially beneficial learning, community learning, learning through commu-nity service, etc. The concept of service learning has been incorporated into projects such as the Erasmus+ project „Change Your Role“, which aimed to bring together different ways of working with young people in the environmental field to lead them towards active citizenship (Borovinová, 2021). Another Erasmus+ project „Trainee“ focussed on developing effective approaches in the field of community learning (i.e. service learning) in the context of training professio-nals working in the field of youth employment support (Trainee Project, n.d.; Ferlin, 2022). Several papers related to service learning have been published, e.g. the report on the approach that combines environmental education, citizen science and community learning to develop green skills (Robinson, 2024), or the paper that provides important insights into the theoretical and methodological challenges of measuring adult participation in lifelong learning (Mikulec, 2023). The role of education for sustainable development (ESD) was explored, emphasising how education for sustainability impacts on wider societal understandings of public interest 304 29–30 May 2025, Ljubljana, Slovenia and adult learning (Bogataj, 2021). Community service learning in primary and secondary schools has also been analysed. The literature also addresses the concept of academic service learning in a variety of ways, from its de-finition as a teaching method to definitions that view academic service learning as a movement for social change. It was noted that academic service learning is becoming increasingly important and promoted at European level (Grandić, 2019). The current state of education for sustainable development in Slovenia was also analysed in a paper presenting the situation on the Slovenian education market with a focus on adult education and lifelong learning (Rozman, 2020). 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 3.2 TexUnite Erasmus+ project The TexUnite project (Erasmus+) promotes the key competences needed to achieve sustainability goals by in- introducing service learning in textile, clothing and fashion education through project-based seminars. The introducing service learning in textile, clothing and fashion education through project-based seminars. The develops an online educational seminar for higher education with digitally enhanced teaching and learning arran troducing service learning in textile, clothing and fashion education through project-based seminars. The project project develops an online educational seminar for higher education with digitally enhanced teaching and project develops an online educational seminar for higher education with digitally enhanced teaching and gements for the implementation of sustainability-oriented service learning project seminars with external partners. - learning arrangements for the implementation of sustainability-oriented service learning project seminars with learning arrangements for the implementation of sustainability-oriented service learning project seminars with The virtual exchange method will be used to create an intercultural exchange between the six European partner external partners. The virtual exchange method will be used to create an intercultural exchange between the external partners. The virtual exchange method will be used to create an intercultural exchange between the universities. The project brings digitalisation and sustainability together. six European partner universities. The project brings digitalisation and sustainability together. six European partner universities. The project brings digitalisation and sustainability together. The integration of service learning into a curriculum trains democratic values and awareness and leads The integration of service learning into a curriculum trains democratic values and awareness and leads university The integration of service learning into a curriculum trains democratic values and awareness and leads teachers, students and external partners to critical thinking, reflection on textile production and fashion con-university teachers, students and external partners to critical thinking, reflection on textile production and university teachers, students and external partners to critical thinking, reflection on textile production and sumption, cooperation and social competence as well as international exchange (TexUnite, n.d.). fashion consumption, cooperation and social competence as well as international exchange (TexUnite, n.d.). fashion consumption, cooperation and social competence as well as international exchange (TexUnite, n.d.). The partners of the TexUnite project are: University of Education Freiburg, Germany (lead), University of The partners of the TexUnite project are: University of Education Freiburg, Germany (lead), University of Applied The partners of the TexUnite project are: University of Education Freiburg, Germany (lead), University of Sciences Albstadt-Sigmaringen, Germany, Gheorghe Asachi Technical University of Iaşi, Romania. Trakia Uni-Applied Sciences Albstadt-Applied Sciences Albstadt-Sigmaringen, Germany, Gheorghe Asachi Technical University of Iaşi, Romania. Sigmaringen, Germany, Gheorghe Asachi Technical University of Iaşi, Romania. versity Stara Zagora, Bulgaria, University of Ljubljana, Slovenia and Ege University, Izmir, Turkey. Trakia University Stara Zagora, Bulgaria, University of Ljubljana, Slovenia and Ege University, Izmir, Turkey. Trakia University Stara Zagora, Bulgaria, University of Ljubljana, Slovenia and Ege University, Izmir, Turkey. Figure Figure 3: Figure 3: TexUnite logo and QR 3: TexUnite logo and QR TexUnite logo and QR 4. COCLUSIONS 4. COCLUSIONS 4. COCLUSIONS So far, no work has been found that deals with the method of service learning specifically for sustainability in So far, no work has been found that deals with the method of service learning specifically for sustainability in the So far, no work has been found that deals with the method of service learning specifically for sustainability in the textile, clothing and fashion industry. Therefore, the method of service learning has great potential for textile, clothing and fashion industry. Therefore, the method of service learning has great potential for implemen the textile, clothing and fashion industry. Therefore, the method of service learning has great potential for -implementation in higher education curricula in the field of sustainability in the textile and fashion industry in tation in higher education curricula in the field of sustainability in the textile and fashion industry in Slovenia and implementation in higher education curricula in the field of sustainability in the textile and fashion industry in Slovenia and abroad. In this field, the contribution of the TexUnite project will undoubtedly be significant. abroad. In this field, the contribution of the TexUnite project will undoubtedly be significant. Slovenia and abroad. In this field, the contribution of the TexUnite project will undoubtedly be significant. Integrating the concept of service learning into the curricula of textiles, clothing and fashion higher education Integrating the concept of service learning into the curricula of textiles, clothing and fashion higher education Integrating the concept of service learning into the curricula of textiles, clothing and fashion higher education can pose significant challenges due to time constraints, limited financial and human resources and partnership can pose significant challenges due to time constraints, limited financial and human resources and partnership can pose significant challenges due to time constraints, limited financial and human resources and partnership issues. To effectively overcome these constraints, higher education institutions need to set clear goals and issues. To effectively overcome these constraints, higher education institutions need to set clear goals and invol issues. To effectively overcome these constraints, higher education institutions need to set clear goals and -involve teachers, students and the learning environment in defining these goals. Service learning projects must involve teachers, students and the learning environment in defining these goals. Service learning projects must ve teachers, students and the learning environment in defining these goals. Service learning projects must also also harmonise curriculum requirements and educational goals. also harmonise curriculum requirements and educational goals. harmonise curriculum requirements and educational goals. Overall, integrating service learning into higher education not only enhances students’ academic experiences, Overall, integrating service learning into higher education not only enhances students’ academic experiences, Overall, integrating service learning into higher education not only enhances students’ academic experiences, but also prepares them to be responsible citizens. By actively engaging with the community and society, but also prepares them to be responsible citizens. By actively engaging with the community and society, but also prepares them to be responsible citizens. By actively engaging with the community and society, students students develop a sense of social responsibility that extends beyond their academic pursuits. students develop a sense of social responsibility that extends beyond their academic pursuits. develop a sense of social responsibility that extends beyond their academic pursuits. The project TexUnite is co-funded by the European Union. The project TexUnite is co-funded by the European Union. The project TexUnite is co-funded by the European Union. 5. REFERENCES 5. REFERENCES Black, Sandy. 2012. Black, Sandy. 2012. The Sustainable Fashion Handbook. The Sustainable Fashion Handbook. London: Thames & Hudson. London: Thames & Hudson. Bogataj, Nevenka. 2021. 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Bogataj, Nevenka. 2021. „Vzgoja in izobraževanje za trajnostni razvoj širita razumevanje javnega interesa v izobraževanju odraslih.“ Andragoška Spoznanja 27 (1): 121–138. https://doi.org/10.4312/as/9747. Borovinová, Katarína, Martina Dobiášová, Lea Marovt, Gregor Cerar, Mária Butyka, Laura Bondiuc, and Mihai Prisacariu. 2021. Spremeni svojo vlogo: Priročnik za učitelje za izobraževanje o trajnostnem razvoju v skupnosti. https://ekosola.si/wp-content/uploads/2021/07/ Spremeni-svojo-vlogo_priro%C4%8Dnik_2021.pdf. Bringle, Robert G., and Julie A. Hatcher. 1996. „Implementing Service Learning in Higher Education.“ Journal of Higher Education 67 (2): 221–239. https://doi.org/10.1080/00221546.1996.11780257. Ferlin, Štefan. 2022. „Projekt TRAINEE skozi skupnostno učenje za večjo zaposljivost mladih.“ Urad RS Za Mladino - mlad.si, December 9, 2022. https://www.mlad.si/projekt-trainee-skozi-skupnostno-ucenje-za-vecjo-zaposljivost-mladih/. Fletcher, Kate. 2016. 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Rozman, Tomaž, and Maja Frangež Rozman. 2020. „Education for Sustainability: Learning Methods and the Current State in Slovenia (a Preliminary Study).“ International Journal of Smart Education and Urban Society (IJSEUS) 11 (1): 41–63. https://doi.org/10.4018/ IJSEUS.2020010104. TexUnite. n.d. Project Summary. URL: https://texunite.eu/ (last accessed on 01. 02. 2025). Trainee Project. n.d. “Trainee Project – TRAINEE: Training and Raising Awareness through In-service Networks for Employment and Entrepreneurship.” https://traineeproject.eu/. 306 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-authors: University of Ljubljana University of Ljubljana University of Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences Faculty of Natural Sciences Matejka Bizjak, prof. dr. Barbara Simončič, prof. dr. Klara Kostajnšek, assis. prof. dr. and Engineering and Engineering and Engineering Department of Textiles, Graphic Arts and Design Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška 5 Snežniška 5 Snežniška 5 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia +386 1 200 32 00 +386 1 200 32 00 barbara.simoncic@ntf.uni-lj.si klara.kostajnsek@ntf.uni-lj.si matejka.bizjak@ntf.uni-lj.si Brigita Tomšič, assoc. prof. dr. Alenka Pavko Čuden, prof. dr. +386 1 200 32 00 University of Ljubljana University of Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences and Engineering, and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška 5 Snežniška 5 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia +386 1 200 32 00 alenka.cuden@ntf.uni-lj.si brigita.tomsic@ntf.uni-lj.si 307 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION TEXUNITE – ERASMUS+ PROJECT ON SERVICE LEARNING IN THE FIELD OF SUSTAINABILITY IN TEXTILE AND FASHION EDUCATION Matejka Bizjak1, Alenka Pavko Čuden1, Barbara Simončič1, Manuela Bräuning2, 3 Mirela Blaga , Zlatina Kazlacheva 4 , Mustafa Ertekin 5 , Dirk Höfer 6 and Anne-Marie Grundmeier 6 1University of Ljubljana, Slovenia 2 University of Applied Sciences Albstadt-Sigmaringen, Germany 3Gheorghe Asachi Technical University of Iasi, Romania 4Trakia University Stara Zagora, Bulgaria 5Ege University, Turkey 6University of Education Freiburg, Germany Abstract: The EU textile and fashion sector is required to transform into a sustainable system. All stakeholders need to adapt to EU regulations and engage at local and global level. The TexUnite project promotes the key com-petences needed to achieve the sustainability goals by introducing Service Learning (SL) in textile and fashion education through project-based seminars. Lecturers are enabled to carry out SL projects through active partici-pation in the Sustainable Textile Lab training module. The project develops an online further education seminar for higher education with digitally enhanced teaching and learning arrangements for the implementation of susta-inability-oriented service-learning project seminars with sustainability-oriented and socially committed external partners. In order to establish an intercultural exchange between the projects at six European partner universities, the method of Virtual Exchange is used. The project brings together digitalisation and sustainability. The results will be made available as Open Educational Resources. The integration of SL into a curriculum trains democratic values and awareness and leads university teachers, students and external partners to critical thinking, reflection on textile production and fashion consumption, cooperation and social competence. Keywords: TexUnite, textiles, fashion, sustainability, Service Learning, Virtual Exchange, Open Educational Re-sources. 1. INTRODUCTION The textile and fashion sector in the European Union (EU) is currently undergoing a profound transformation ai-med at creating a sustainable system in response to pressing environmental and social challenges. In the past, the industry has struggled with problems such as pollution, excessive waste and labour exploitation, mainly driven by the fast fashion model, which relies on rapid production and low costs (Velimirović, 2023; Corso, 2024; Van Keulen, 2024) In 2022, the EU launched the Green Deal and the Strategy for Sustainable and Circular Textiles, which set am-bitious targets for eco-design, waste reduction, and sustainable production practises. These initiatives reflect the growing recognition of the importance of environmental awareness in the textile industry. However, the transition is not without its challenges, including the shortage of skilled labour, the need to overhaul the supply chain and balancing consumer demand for fast fashion with sustainable practises (Tappr, 2023; Dubey, 2025; Van Iterson, 2022). On 6 June 2023, the European Commission published a transition pathway for the textile ecosystem, co-created with industry stakeholders. This pathway describes specific actions to improve sustainability and di-gitalisation in the industry, with around 50 actions across eight building blocks. These actions promote circular and sustainable practises while supporting SMEs to innovate and grow in international markets. In addition, the pathway emphasises the importance of upskilling and reskilling the workforce through access to lifelong learning opportunities (European Commission, 2023). 308 29–30 May 2025, Ljubljana, Slovenia The regulatory framework continues to evolve to support this transformation, with key policies such as the Ecode-sign Sustainable Products Regulation (ESPR) and the ban on products made using forced labour. These regula-tions aim to promote the circular economy, accountability and transparency within the industry, while encouraging companies to adopt sustainable practises throughout their supply chain. Despite these efforts, the industry is stru-ggling with the complex dynamics of consumer expectations and the economic impact of switching to sustainable models, particularly for small and medium-sized enterprises (Hussain, 2023; Burkhardt, 2023; EISMEA, 2021). Prominent controversies include debates about greenwashing, the effectiveness of regulations and the commer-cial viability of sustainable practises for brands traditionally reliant on fast fashion. The EU textile and fashion sector continues its transition towards sustainability and remains a focal point for discussions on environmental responsibility, ethical labour practises and the future of consumer behaviour in an increasingly environmentally conscious market. All stakeholders need to adapt to EU regulations and engage on a local and global scale. (Campbell, 2024; European Commission, 2023). 2. TEXUNITE PROJECT 2.1 Project core The international project TexUnite aims to improve the key competences required to achieve sustainability goals through the integration of Service Learning and Virtual Exchange in textile and fashion education. The project is the first international study programme with Service Learning components in the textile and fashion sector in Europe. By implementing Service Learning in project-based seminars with partner organisations such as NGOs, communities or sustainability-oriented companies, the initiative promotes environmental and social commitment in higher education. The aim is to give students the opportunity to get involved in social and sustainable activities as part of their academic learning and to see what they can contribute. As a pedagogical strategy, Service Lear-ning enables students to cultivate sustainability-oriented knowledge and attitudes while serving the community and providing them with an active learning experience. All activities are in line with European approaches to susta-inability in the textile and fashion industry (TexUnite, 2024). Figure 1: Service Learning as a basic teaching method As part of TexUnite, the University of Education Freiburg in Germany is cooperating with the Albstadt-Sigmarin-gen University in Germany and universities from four different countries: the George Asachi Technical University of Iaşi in Romania, the University of Ljubljana in Slovenia, the Trakia University of Stara Zagora in Bulgaria and Ege University in Izmir, Turkey. The 3-year project, which will end in August 2027, is co-funded by the European 309 29–30 May 2025, Ljubljana, Slovenia Union‘s Erasmus+ programme, one of the most successful initiatives in Europe, which is also of great importance for higher education programmes (TexUnite, 2024). The project TexUnite is co-funded by the European Union. 2.2 Project objectives The general objective of the Erasmus+ TexUnite project is to promote the key competences needed to achieve sustainability goals by introducing the concept of Service Learning in textile and fashion education. The TexUnite project has three main specific main objectives: - Sustainable Textile Lab: Development and implementation of an online further education seminar with digitally enhanced teaching and learning arrangements to conduct sustainability-oriented Service Lear-ning project seminars with students and to enter into an intercultural exchange using the Virtual Exchan-ge method. - Service Learning projects: Development, implementation and evaluation of Service Learning projects at each partner university. On the basis of the SusTexLab, partners for the Service Learning projects are found, e.g. NGOs, communities or sustainability-oriented companies, and integrated into international tandems via Virtual Exchange. - Open Educational Resources: Creation of OER, consisting of the teaching and learning materials of the SusTexLab and the content of the SL projects on the open access repository ZOERR and the pro-ject presentation on the European platform EPALE (TexUnite, 2024). The project focuses on economic models of sustainability in the textile and fashion sector as well as on an analy-sis of EU regulations on sustainable textile industry and their relevance for partner countries and is linked to the priority environment, green skills and the fight against climate change. 2.3 Research steps The TexUnite project develops in six steps: Figure 2: 6-phase TexUnite project plan 3. IMPLEMENTATION AND RESULTS The introduction of sustainability-oriented SL projects in textile, clothing and fashion education offers students the opportunity to actively engage with real-world challenges. Such projects can educate students about the environmental and social issues facing the textile and fashion industry, thus increasing their sense of responsibility and awareness. Students are challenged to develop sustainable solutions and encourage creativity and innovation in the design of environmentally friendly processes or products. SL projects involve collaboration with industry 310 29–30 May 2025, Ljubljana, Slovenia stakeholders, local communities and experts, fostering a sense of collective responsibility. They provide students with hands-on experience in implementing sustainable practises and prepare them for future careers focused on environmental protection. In addition, SL projects can have a positive impact on local communities by promoting sustainable practises and improving community well-being. Addressing the environmental and climate impacts of the textile and fashion industry through sustainability-focused Service Learning is critical to creating a more responsible and resilient industry while educating and empowering the next generation of professionals and leaders. Students will develop critical thinking and empathy as well as problem-solving skills to address climate change and environmental issues and find solutions for transforming the textile and fashion sector into a circular system (TexUnite, 2024). 4. CONCLUSION Addressing sustainability issues in the fashion and textiles is in line with the concept of global citizenship educa-tion. Students who participate in real-world projects gain a broader perspective on global challenges and develop a sense of responsibility for creating a more sustainable and just world. The TexUnite project promotes the key competences required to achieve sustainability goals by introducing Ser-vice Learning into textile and fashion education through project-based seminars. The integration of Service Lear-ning concept into a curriculum fosters democratic values and awareness and leads university teachers, students and external partners to critical thinking, reflection on textile production and fashion consumption, cooperation and social competence as well as international exchange. To summarise, the TexUnite project has the potential to create synergies between different sectors, impact educa-tion and training, engage young people and contribute to wider societal and environmental goals. It is in line with the principles of experiential learning, interdisciplinary collaboration and the promotion of sustainable practises. By building a bridge between the academic and non-academic communities and using their knowledge to help solve environmental, social and economic challenges, universities fulfil their third mission of social engagement. 5. REFERENCES Burkhardt, Delara. “REPORT on an EU Strategy for Sustainable and Circular Textiles | A9-0176/2023 | European Parliament.” © European Union, 2023 - Source: European Parliament, May 9, 2023. Accessed December 21, 2024. https://www.europarl.europa.eu/doceo/ document/A-9-2023-0176_EN.html. Campbell, Niamh. “Driving the Apparel Sector Just Transition.” Innovation forum. Innovation Forum, November 7, 2024. Accessed January 30, 2025. https://www.innovationforum.co.uk/articles/driving-the-apparel-sector-just-transition. Corso, Tommaso & Paolucci, Federica. 2024. “EU Strategy for Sustainable and Circular Textiles: Key Actions at a Glance | Econyl Blog.” Econyl, October 31, 2024. https://econyl.aquafil.com/eco-design-magazine/eu-strategy-for-sustainable-and-circular-textiles-key-actions-at-a-glance/. Dubey, Manoj. “European Textile Industry’s Response to Stricter Rules.” Global Textile Times, February 25, 2025. https://www. globaltextiletimes.com/apparel/european-textile-industry-s-response-to-stricter-rules/. European Commission. “Commission and Industry Players Commit to Make the Textile Sector Greener, More Digital and Competitive,” June 6, 2023. Accessed February 10, 2025. https://single-market-economy.ec.europa.eu/news/commission-and-industry-players-commit-make-textile-sector-greener-more-digital-and-competitive-2023-06-06_en. European Innovation Council and SMEs Executive Agency (EISMEA). “Towards a More Sustainable & Circular Fashion Sector: Four COSME Projects Making It Happen,” n.d. https://eismea.ec.europa.eu/news/towards-more-sustainable-circular-fashion-sector-four-cosme-projects-making-it-happen-2021-06_en. 311 29–30 May 2025, Ljubljana, Slovenia Hussain, Tanveer. “Ultimate Guide to EU Strategy on Sustainable and Circular Textiles.” The Textile Think Tank, July 26, 2023. https:// thetextilethinktank.org/ultimate-guide-to-eu-strategy-on-sustainable-and-circular-textiles/. Tappr. “The EU Strategy for a Sustainable & Circular Textile Sector,” December 6, 2023. Accessed February 1, 2025. https://www.usetappr. com/blog/eu-strategy-sustainable-and-circular-textiles. TexUnite. “About.” Accessed February 10, 2025. https://texunite.eu/index.php/about/. Van Iterson, Rannveig. “EU Sustainable Textiles Strategy: Everything You Need to Know.” Ohana Consultancy, October 22, 2024. https:// www.ohanapublicaffairs.eu/2022/07/28/eu-strategy-sustainable-circular-textiles/. Van Keulen, Roos. “EU Strategy for Sustainable Textiles: 5 Takeaways | Earth.Org.” Earth.Org, January 5, 2024. https://earth.org/5-takeaways-from-the-new-eu-circular-fashion-strategy/. Velimirovic, Milica. “Threads of Progress: Reviewing the History and Building a Sustainable Future for the EU’s Textile Industry - BioLUSH.” BioLUSH - (blog), December 11, 2023. https://biolush.eu/threads-of-progress-reviewing-the-history-and-building-a-sustainable-future-for-the-eus-textile-industry/. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-authors: Faculty of Natural Sciences Faculty of Technics and Engineering and Technologies of Yambol and Engineering Department of Textiles, Graf Ignatiev 38 Department of Textiles, Graphic Arts and Design University of Ljubljana University of Ljubljana Trakia University of Stara Zagora Faculty of Natural Sciences Matejka Bizjak, prof. dr. Barbara Simončič, prof. dr. Zlatina Kazlacheva, prof. dr. Graphic Arts and Design Snežniška 5 8600, Yambol, Bulgaria +35 9889 339 914 Snežniška 5 1000 Ljubljana, Slovenia zlatinka.kazlacheva@trakia-uni.bg 1000 Ljubljana, Slovenia +386 1 200 32 00 matejka.bizjak@ntf.uni-lj.si Alenka Pavko Čuden, prof. dr. Gençlik Caddesi University of Ljubljana 35040 Bornova-Izmir, Turkey Faculty of Natural Sciences +90 2323 112 049 and Engineering mustafa.ertekin@ege.edu.tr +386 1 200 32 00 Mustafa Ertekin, assoc. prof. dr. Ege University barbara.simoncic@ntf.uni-lj.si Department of Textiles, Graphic Arts and Design Snežniška 5 Dirk Höfer, apl. prof. dr. med 1000 Ljubljana, Slovenia University of Education alenka.cuden@ntf.uni-lj.si Kunzenweg 21 79117 Freiburg, Germany Manuela Bräuning, prof. dr. +49 761 682-291 Albstadt-Sigmaringen University dirk.hoefer@ph-freiburg.de Poststr.6 72458 Albstadt, Germany Anne-Marie Grundmeier, prof. dr. +49 7571 732 9276 University of Education braeuning@hs-albsig.de Kunzenweg 21 79117 Freiburg, Germany Mirela Blaga, prof. dr. +49 761 682 530 ‘’Gheorghe Asachi’’ grundmeier@ph-freiburg.de Technical University of Iasi 67 D. Mangeron Street 700050, Iasi, Romania +40 232 701 221 mirela.blaga@academic.tuiasi.ro 312 INVITED LECTURES 29–30 May 2025, Ljubljana, Slovenia SESSION-INVITED LECTURE ORAL PRESENTATION IMPLEMENTATION OF THE EU PACKAGING AND PACKAGING WASTE REGULATION (PPWR) FOR SLOVENIA AND EUROPE: CHALLENGES AND OPPORTUNITIES Gregor Lavrič1 1Pulp and Paper Institute, Slovenia Abstract: On December 16, 2024, the Council of the European Union officially adopted the EU Packaging and Packaging Waste Regulation (PPWR), making it legally binding across all EU member states. The regulation en-tered into force at the beginning of 2025, with its provisions becoming applicable after a general transition period of 18 months. The regulation is considered one of the most significant legal frameworks in the field of packaging, with major implications for all EU member states, including Slovenia. This paper provides an overview of the key elements of the PPWR, its implications for stakeholders, and explores sustainable approaches and innovative solutions within the packaging sector to meet the new standards and promote a circular economy. Keywords: EU Packaging and Packaging Waste Regulation, Sustainable packaging, Recycling, Circular eco-nomy. 1. INTRODUCTION The European Union recently adopted the long-anticipated PPWR, a pivotal step towards improving the sus-tainability of packaging across the union. Initially proposed by the European Commission in 2022, the regulation introduces a broad set of binding requirements and ambitious targets aimed at reducing packaging waste and pro-moting recycling, reuse, and circularity. As the most prolonged regulatory process in the EU’s history, the PPWR has been at the centre of intense lobbying efforts. According to the Food Packaging Forum, concerns have been raised that the final version has been significantly diluted by the influence of profit-driven interest groups (Food Packaging Forum, 2025). 2. OVERVIEW OF THE PPWR The PPWR introduces several stringent measures aimed at reducing packaging waste and enhancing recycling and reuse rates across the EU. Among its provisions, the regulation mandates a significant reduction in the use of non-recycled raw materials in packaging, setting minimum recycled content requirements for various packaging types, such as a minimum of 25% recycled content for plastic bottles by 2025. The regulation also bans materials that are not easily recyclable and limits the use of single-use packaging in food and beverage services. Another crucial provision is the phased elimination of PFAS in food-contact materials (European Commission, 2025). Despite these advancements, the success of the regulation will depend heavily on the establishment of unified systems for the collection, sorting, and recycling of different materials across EU member states. In Slovenia, for example, different municipalities still employ varying systems for waste collection and separation, creating con-fusion and inefficiencies. Some regions use a colour-coded bin system (e.g. blue for paper, yellow for packaging etc.) (Javni holding Ljubljana, 2021), while others separate waste into “dry” and “wet” categories (Javno podjetje Komunala Slovenj Gradec, 2016). This lack of harmonisation—on such a small national territory—is unacceptable and undermines the efficiency of the overall waste management system. 315 29–30 May 2025, Ljubljana, Slovenia 3. CHALLENGES AND OPPORTUNITIES IN IMPLEMENTATION The regulation places significant emphasis on recycling and reusing packaging products and materials in all areas where this is possible. The main reason for updating the regulation is the fact that, despite various past efforts, packaging is still considered one of the key global environmental challenges. The packaging industry also re-mains one of the main consumers of virgin (non-recycled) raw materials. Estimates suggest that as much as 40% of all freshly produced plastic and 50% of all paper and cardboard production is used for packaging purposes. Moreover, packaging is responsible for approximately 36% of all municipal solid waste. The high consumption of packaging materials, coupled with low levels of reuse and recycling, significantly hampers the development of a low-carbon society and a circular economy (European Commission, 2025). Data from Eurostat and various market reports, monitored and utilized by the European Parliament, also highlight an increasing share of packaging products whose properties can obstruct recycling processes. Packaging is deemed “non-recyclable” if it cannot be separately collected or presents challenges for the most advanced sorting and recycling processes within the European Union. Between 2012 and 2020, the share of technically non-re-cyclable packaging increased significantly. Moreover, even packaging with favourable properties for recycling is often not recycled because the necessary systems for collection, sorting, and processing are not available, regionally accessible, or cost-efficient. Recycled raw materials or recycled products are frequently of insufficient quality to meet market and secondary raw material user demands (European Commission, 2025). Notably, even if there were a hypothetical breakthrough in the research and development of new and advanced packaging materials and these materials were introduced into the market within a few years, this would not nec-essarily result in a significant improvement. The current pace of testing and approval of new materials, especially those coming into direct contact with food, is exceptionally slow. For the vast majority of these materials, there are also (at least likely) no suitable large-scale recycling processes in place, further complicating their effective integration into the circular economy. It is worth noting that refill and reuse concepts still represent a significant op-portunity for improvements in the packaging sector, particularly in Slovenia. However, this is achievable only if the systems supporting these concepts are well-organized and safe for both products and consumers (Lavrič, 2023). The regulation also does not clearly define how the clear environmental benefit of packaging or packaging ma-terials will be demonstrated. However, it is almost certain that such packaging will need to be made from circular and alternative raw material sources. The demanding challenge in Slovenia is also broader and more balanced implementation and realization of various concepts for the multiple use of packaging (refill and reuse concepts), which should be enabled by retail stores or chains with a more extensive offer of bulk products. Of course, each time the issue arises about the safety of packaging, which, with appropriate guidelines and directions, is entirely manageable. As already mentioned, the regulation places great emphasis on the reuse and recycling of packaging or packag-ing materials. For paper and cardboard, which, along with various types of plastic, are the most commonly used packaging materials in the world, recycling does not pose significant challenges. According to CEPI data, 71.4% of paper and cardboard were recycled in the European Union in 2021 (CEPI, 2022). This is 2% less than in 2020 but more than 40% higher than the percentage for plastic materials. According to Eurostat, the recycling rate for plastic materials in 2020 was 38% (Eurostat, 2023). This ratio in favour of paper certainly partly stems from the fact that recycling processes for plastic materials are more complex and challenging than those for paper. Despite the variety of papers, cardboards, and corrugated boards, their primary raw material is almost always the same—cellulose fibre, which can be recycled up to 25 times with adapted processes, according to the latest data (Packaging Europe, 2023). Given these facts and the other properties of paper and plastic, we can conclude or predict that, in the future, concepts will likely be more developed where plastic materials will be used for various packaging products intended primarily for reuse (re-fill and reuse), while paper will be used where plastic is not reasonable or justified based on various evaluation parameters, such as barrier properties, weight-to-strength ratio, cost-effectiveness, and environmental impact assessments. Such concepts are already emerging in practice, particularly abroad. One recently prominent ex-ample, comes from the global fast-food chain McDonald’s. In France, at the end of 2022, the corporation replaced its primarily paper fry packaging with reusable plastic for the first time in its history (Abboud, 2023). 316 29–30 May 2025, Ljubljana, Slovenia Especially for warm or hot and greasy foods—such as French fries—there is an easy transfer of certain (potential-ly harmful) components from the packaging to the food through the medium (hot oil). Therefore, the use of papers or cardboard made almost entirely from virgin cellulose fibres is recommended or prescribed. After use, this type of packaging also poses challenges for recycling. These papers and cardboards often contain films or coatings to improve their barrier properties, which can be problematic for conventional recycling processes. Additionally, once paper and cardboard come into direct contact with food, they are no longer suitable for recycling into similar-qual-ity materials, even if their raw composition would allow it, mainly for hygienic reasons. In practice, this means that high-quality papers and cardboards, made almost entirely from virgin cellulose fibres, are, after just a few minutes of use, downgraded to much lower-quality papers and cardboards that are no longer suitable for food packaging. The market also offers numerous applications in medicine, pharmaceuticals, and food, where the use of recycled materials for packaging is not suitable or even prohibited. Therefore, it is crucial that we continue developing di-verse packaging applications from alternative raw material sources. One of the main challenges in using various alternative raw materials for the production of packaging materials and applications will undoubtedly be ensuring their purity, which will enable the safe packaging of various types of products. Even when this is indisputable, it does not necessarily mean that the newly developed material can be used for food packaging. The material or newly developed substance must first be approved by the relevant authority. In the European Union, this responsibility lies with the European Food Safety Authority (EFSA). Different countries also refer to and apply different, often uncoordinated national regulations and guidelines. The current pace of development of new materials and applications is not well matched by the relevant authorities. Waiting times for material approval are very long, and the procedures are expensive and rigid. Certain institutions hold a monopoly over these procedures and, due to various interests, do not allow the expansion of research to other institutions, which would certainly accelerate the evaluation. This results in a highly rigid, slow, and non-competi-tive system that collapses under the burden of thousands of new materials, substances, and compounds waiting to be evaluated and approved. If this area becomes better regulated in the future—particularly regarding the approval processes for new ma-terials—some of the most suitable candidates will likely be materials based on various forms of (nano)cellulose, as they can be easily integrated into existing recycling streams and, in some cases, even enhance the functional properties of paper-based packaging (Lavrič, 2018).This is a significant advantage in the context of recycling new bio-based materials, as recycling processes for other materials, such as chitosan or alginate, do not currently exist. They are currently classified as biodegradable or compostable, which is acceptable when these materials enrich the soil or compost during their degradation. However, almost every such breakdown releases CO₂ into the environment as a by-product, which, under the current aspirations for a CO ₂-neutral society, can present a major challenge in certain frameworks. Given the current recycling capacity of the European Union, the draft regulation still allows biodegradable ma-terials to undergo biodegradation as the only end-of-life scenario if they are demonstrably beneficial to the envi-ronment and made from biodegradable and compostable polymers. Member States will have to decide, based on their own waste collection schemes and infrastructure, whether to mandate the use of compostable plastics, particularly for lightweight plastic bags. If a country lacks the capacity to recycle these bags, it is better to mandate the use of compostable ones and accept some of the disadvantages this step entails. This is also important to avoid consumer confusion regarding proper sorting and disposal. All other plastic packaging must still undergo material recycling, and it is crucial that biodegradable bags are not mixed in with recyclable plastics, as this could disrupt the recycling process. 4. CHALLENGES AND OPPORTUNITIES IN IMPLEMENTATION These facts further confirm the need for developing new materials, despite the lack of fully developed recycling processes for them. It is also true that such exceptions are mainly possible due to poor infrastructure and process-es that are problematic even for well-established plastic materials in Slovenia. However, poor infrastructure and the lack of suitable recycling processes are not the only reasons why non-recy-clable materials will remain present in the market in the coming years. For some applications, it is more practical for the material to decompose or accelerate the degradation of certain waste rather than be recycled. Such sce- 317 29–30 May 2025, Ljubljana, Slovenia narios include different types of waste collection bags, where their purpose and nature make degradation a more practical solution than recycling, which would be challenging and largely impractical due to contamination. 5. REFERENCES: Abboud, Leila. Macron Versus McDonald’s: How France Ditched Disposable Food Packaging. Financial Times. URL: https://www.ft.com/ content/baa23798-7c6b-45be-b6a1-00b446976331 (last accessed on 13 February 2025). CEPI. 2022. Key Statistics 2021 – European Pulp and Paper Industry. Brussels: Confederation of European Paper Industries. URL: https:// www.cepi.org/wp-content/uploads/2022/07/Key-Statistics-2021-Final.pdf (last accessed on 14 April 2025). European Commission. Packaging Waste. URL: https://environment.ec.europa.eu/topics/waste-and-recycling/packaging-waste_en (last accessed on 13 February 2025). Eurostat. 2023. Packaging Waste Statistics. Brussels: European Commission. URL: https://ec.europa.eu/eurostat/statistics-explained/index. php?title=Packaging_waste_statistics (last accessed on 14 April 2025). Food Packaging Forum. European Council Adopts Final Provisions of PPWR. URL: https://foodpackagingforum.org/news/european-council-adopts-final-provisions-of-ppwr (last accessed on 13 February 2025). Javni holding Ljubljana. Plakat za četrtne skupnosti – Ravnanje z odpadki. Ljubljana: Voka Snaga. URL: https://www.vokasnaga.si/sites/ www.jhl.si/files/dokumenti/plakat_za_cetrtne_skupnosti_1.6.2021_0.pdf (last accessed on 14 April 2025). Komunala Slovenj Gradec. 2016. Priročnik za ravnanje z odpadki. Slovenj Gradec: Javno podjetje Komunala Slovenj Gradec d.o.o., Pameče 177a. URL: https://www.komusg.si/Portals/0/Dejavnosti/Ravnanje-z-odpadki/prirocnik-za-ravnanje-z-odpadki-2016.pdf (last accessed on 14 April 2025). Lavrič, Gregor. 2018. The Influence of Nanofibrillated Cellulose on Mechanical and Printing Properties of Packaging Paper. Master’s thesis, University of Ljubljana. URL: https://repozitorij.uni-lj.si/IzpisGradiva.php?id=103024&lang=eng (last accessed on 14 April 2025). Lavrič, Gregor. 2023. Development of Advanced Packaging Materials from Bio-Based Sources. PhD diss., University of Ljubljana. URL: https://repozitorij.uni-lj.si/IzpisGradiva.php?id=147526&lang=slv (last accessed on 13 February 2025). Packaging Europe. New Study Suggests Cartonboard Can Be Recycled 25 Times Without Loss of Integrity. URL: https://packagingeurope. com/news/new-study-suggests-cartonboard-can-be-recycled-25-times-without-loss-of-integrity/7752.article (last accessed on 13 February 2025). ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Gregor Lavrič Department for Graphics and Packaging Pulp and Paper Institute, Ljubljana Bogišićeva 8 1000, Ljubljana, Slovenija +386 41 206 395 gregor.lavric@icp-lj.si 318 29–30 May 2025, Ljubljana, Slovenia SESSION-INVITED LECTURE ORAL PRESENTATION EXPLORING SCULPTURAL REALISM THROUGH WAX MODELING AND 3D PRINTING: A PERSONAL ARTISTIC EVOLUTION Anna Sacher Santana Austria Abstract: From the outset of this artistic trajectory, the central objective has been the faithful materialization of sculptural forms as vividly envisioned in the mind’s eye—highly detailed, three-dimensional internal images arising through dreams, meditation, or moments of contemplative focus. The initial challenge involved selecting a material capable of accurately capturing these internal visions. Natural materials such as stone or wood rarely conformed to the desired base forms, and manual carving proved limiting. Furthermore, tactile engagement in the creation process was deemed essential, offering not only creative fulfillment but also therapeutic value through sensory interaction and stimulation of acupuncture points in the hands. While clay presented an initial alternative, it proved unsuitable due to its fragility, cracking during drying, and sensitivity to breaks in the working process. The discovery of wax modelling resolved these issues, offering unparalleled sculpting freedom, enabling the produc-tion of delicate structures, and allowing for long-term iterative work. To complete the wax sculptures, bronze cast-ing was employed. Although bronze is a durable and aesthetically rich material, the process introduced several constraints: reliance on external foundries, long-distance travel, unwanted alterations during casting and finishing, high costs, and loss of control over artistic integrity. A critical turning point occurred when several raw wax models were melted down without consent, prompting a search for alternative methods. This led to the adoption of 3D scanning and printing technologies, initiating a new phase of experimentation and skill acquisition. The process involved learning to scan wax models, refine digital files, and identify suitable materials for post-processing and long-term outdoor durability. An additional artistic imperative was to avoid the appearance of mass production and synthetic plasticity. As a solution, each sculpture is produced in a unique size, undergoes individual surface reworking through manual modelling, and is distinctively finished through hand-painting. Through this hybrid pro-cess of traditional modelling and digital fabrication, significant creative freedom has been achieved. Large-scale sculptures and installations can now be realized, and spatial possibilities previously unattainable in bronze—such as floating forms, suspended compositions, and internally illuminated transparent prints—have become viable. Despite the shift in medium, each sculpture remains a unique work and retains its value within the art market. Key-words: sculptures, wax modelling, 3D printing, forms of human body, artistic expression ADDITIONAL DATA ABOUT AUTHORS Corresponding author Anna Sacher Santana Maggareggerstraße 35 A 9020 Klagenfurt am Wörthersee +43 0650 250 59 67 anna.sachersantana@gmail.com https://www.sachersantana.com/en/home 319 USER INTERFACE AND USER EXPERIENCE 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION USE OF GENERATIVE ARTIFICIAL INTELLIGENCE TOOLS IN TRANSFORMING DESIGN PROCESS Lovro Frece1 and Jure Ahtik1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: This paper explores the integration of generative artificial intelligence (AI) tools into design processes and evaluates their impact on creativity, efficiency and collaboration between human designers and AI. Through theoretical and practical research, the study identifies the opportunities and challenges that generative AI offers in redesigning creative workflows. Interviews with representatives from Slovenian and Belgian design agencies provided insights into real-world applications, leading to the development of a digital communication campaign and a supporting physical brochure. Findings emphasize that while generative AI enhances efficiency and innova-tion, its ethical use requires careful consideration. The research concludes that generative AI should be seen as a complementary tool, augmenting rather than replacing human creativity. Keywords: generative artificial intelligence, design process, creativity, digital campaign, optimization. 1. INTRODUCTION In recent years, technological advances have reshaped the landscape of creative industries, with generative ar-tificial intelligence (AI) tools proving to be transformative instruments. These tools, which use machine learning algorithms to generate new and innovative content, offer designers unprecedented possibilities for efficiency and creativity. Generative AI can produce visual, textual and audio outputs, redefining the traditional design process by automating repetitive tasks and enabling rapid ideation (NVIDIA, 2024; Majumder, 2024). The theoretical foundation of this study highlights the particular capabilities of generative AI, e.g. its ability to re-cognise patterns in large data sets and generate outputs based on these patterns (Feuerriegel et al., 2023). Tools such as ChatGPT, DALL-E, MidJourney and Adobe Firefly exemplify this potential by facilitating content creation, from drafting initial concepts to finalising high-quality designs. In addition, Khroma.ai’s ability to personalise colour palettes and the seamless integration of Adobe Firefly into design workflows underline the practical benefits of these tools (Majumder, 2024). Although the benefits of generative AI are undeniable, challenges remain, particularly concerning ethical and practical considerations. Issues such as copyright infringement, data privacy and bias in AI-generated content require critical evaluation by designers (Lawton, 2024). Furthermore, generative AI lacks the intuitive creativity, emotional intelligence and nuanced decision-making inherent to human designers, emphasising the need for its role as a complementary rather than a replacement tool (Pogla, 2024). By examining current trends and conducting interviews with industry professionals, the study aims to provide actionable insights into the integration of these tools into creative workflows. It also emphasises the importance of continuous education and skill development for designers to adapt to the rapidly evolving technological land-scape. 321 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL 2.1 Materials and Methods The research was conducted in a combination of theoretical analysis and practical experimentation. Interviews were conducted with representatives of Slovenian marketing agencies (Luna/TBWA, DROM Agency and Pristop) and the Belgian design studio WillemsPeeters. These interviews provided insights into the real-world application of generative AI in creative processes. A digital communication campaign for Laški akademski klub was develo-ped, supported by a brochure, to illustrate the effective use of generative AI tools such as Transkriptor, ChatGPT, Adobe Firefly and Khroma AI. 2.2 Development of campaign The digital communication campaign on presenting facts and tips on how to use generative AI for individuals or companies was self-initiated and we did not have a client for it. This meant that we had a free hand in the design, as there were no specific requirements from the client. Our wish was for the campaign to be launched through the social networks of Laški akademski klub. The working methods follow the creative process, but are adapted to the specifics of this project. First, with the help of ChatGPT, we created a creative brief that formed the basis for the creation of a digital campaign and presented it to the president of Laški akademski klub. We then researched the area we wanted to present and, based on the creative brief and research, defined the design area, which we then developed further. In the process of developing the idea, we defined the colours and typography, and with the help of Adobe Firefly AI, we generated avatars that would be the central characters of our campaign and would enrich the creative. This was followed by the design of graphics for the Instagram/Facebook posts, graphics for the Google Display Network which would make people aware of our campaign and a brochure containing all the content presented on the digital channels. We held a meeting with the president of Laški akademski klub, who approved the designs. After that, the project was finalised and the materials were delivered in the agreed formats. Generative AI tools played a crucial role in multiple stages of the design process (Figure 1), streamlining specific tasks and improving overall efficiency. Figure 1: Stages of the design process and generative AI integrations 3. RESULTS AND DISCUSSION The result of the research is a digital campaign for social media and a brochure, the aim of which is to introduce generative artificial intelligence to individuals and companies, give them tips on how to use it in creative processes and show them the most popular generative AI tools currently available. 322 29–30 May 2025, Ljubljana, Slovenia 3.1 Creative brief and research The creative brief was developed with the assistance of ChatGPT, which provided suggestions for the title and structure of the campaign. Interviews with design professionals revealed that generative AI is integrated into the creative processes of the agencies and studios interviewed, from the early stages of campaign planning through to day-to-day work. They mainly use tools such as ChatGPT for conceptual designs, Dall-E, Adobe Firefly and MidJourney for rapid visual content creation. Some agencies are still in the research phase on how to best utilise this technology without losing their own creativity. Although AI enables the automation of certain tasks, such as the rapid creation of storyboards or the easy manipulation of spoken language in videos, they emphasise that AI is not self-sufficient, but is a tool that requires human guidance and critical judgement. They encounter ethical and legal considerations that require careful use. The experience of some shows that despite its effectiveness and cost re-duction, caution is required when introducing AI, particularly when it comes to how the technology will be received by target audiences. Agencies see technology primarily as an assistant that can speed up and improve creative processes, but emphasise the importance of maintaining the human touch and critical thinking in creative work. 3.2 dea development and final design Generative AI tools were used to create visual elements for the campaign, including avatars and colour palettes. Adobe Firefly was used to generate illustrations (Figure 2), while Khroma AI helped select the colour scheme. Figure 2: Adobe Firefly tool and first generations of avatars After six iterations, the result was satisfactory. We removed backgrounds using the Adobe background removal tool built into Photoshop 2024. The result was 10 avatars that could be used for the final design (Figure 3). 323 29–30 May 2025, Ljubljana, Slovenia Figure 3: The final set of avatars with the background removed The text content was extracted from the interview transcripts using ChatGPT and adjusted to avoid mistakes and misinformation. The final designs included posts for social media (Figure 4), adverts for the Google Display Network and a brochure (Figure 5). The campaign successfully demonstrated how generative AI can enhance creativity and efficiency in the design process. For example, the use of Adobe Firefly enabled rapid iteration of illustrations, which would had to be sketched and drawn each time in a time-consuming process. Transkriptor significantly reduced the transcription time of the interviews, which would have been the longest task in this de-sign process. Extracting useful tips and tricks from the transcriptions with ChatGPT was useful to a certain extent, however proofreading and our additions to the final text were very necessary. Figure 4: Three sets of creatives for social media posts Figure 5: Front side and back side of tri-fold brochure 324 29–30 May 2025, Ljubljana, Slovenia 3.3 Feedback and completion The final designs were presented to the president of Laški akademski klub, who approved the campaign. The ma-terials were delivered in the requested formats and the project was successfully completed. The client‘s feedback emphasised the effectiveness of generative AI in creating high-quality visual content in a short timeframe. 3.4 Influence of using generative AI tools on the design process During the ideation phase, ChatGPT was used to generate potential titles for the campaign. While none of the generated titles were directly usable, they provided inspiration and a creative spark that led to the final name of the campaign name. In addition, ChatGPT helped source technical specifications for Google Display Network advertisements, which proved to be accurate and helpful. The research phase benefited from an AI-powered transcription tool. The speech-to-text AI software Transkriptor was used to transcribe interviews with professionals from various agencies. Although the tool significantly accele-rated the transcription process, certain limitations were noted, especially when transcribing Slovenian interviews that contained English terminology. In addition, the extraction of information gathered in the interviews with Chat-GPT was very useful. Although the information was accurate, some generations lacked structure and manual corrections had to be made. Despite these minor shortcomings, the generative AI tools helped to reduce the time required for manual transcription, structuring interview responses and extracting information from long transcripts. Generative AI also played a role in the visual development process. The AI tool Khroma was used to generate co-lour palettes based on selected preferences. This tool provided innovative combinations that would not have been easily imaginable in our minds. Similarly, Adobe Firefly Image 3 was used to create avatars, allowing for rapid prototyping and iterations. The AI-generated avatars were then refined using Photoshop’s „Remove Background“ tool. This shows how AI can help designers without specialised artistic skills, such as digital illustration, to create professional visuals. Although generative AI provided solid benefits in accelerating the design process, critical human oversight was necessary to refine the results and ensure consistency with the creative objectives. The experience with generative AI reaffirmed its potential as a supplementary tool rather than a replacement for human creativity. While it accelerated production, certain limitations, such as inconsistencies in text-based outputs and the need for iterative refinements, emphasized the crucial role of human judgement in the creative process. AI-powered tools provided efficiency and convenience, but require strategic human intervention to ma-ximise their effectiveness. 3.5 Ethical and practical considerations This study emphasises the importance of the ethical use of AI, particularly regarding copyright, data privacy and transparency. Designers need to critically evaluate AI-generated content to avoid issues such as misinformation or unintended bias (Majumder, 2024). Establishing guidelines for responsible AI integration is essential for main-taining trust and creativity in design processes (Lawton, 2024). 4. CONCLUSIONS The study concludes that generative AI tools significantly improve the efficiency and creative potential of design processes. However, their integration requires careful management of ethical and practical considerations. Ge-nerative AI should be seen as a complementary tool that enhances, rather than replaces, human creativity. The study contributes to a deeper understanding of how generative AI can be effectively and ethically implemented into creative workflows, advancing the design industry without diminishing the role of human designers. Furthere research should focus on developing frameworks for the ethical use of AI and exploring its long-term impact on the creative industry. 325 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Feuerriegel, S., Hartmann, J., Janiesch, C. in Zschech, P. Title: Generative AI. URL: https://link.springer.com/article/10.1007/s12599-023-00834-7 (Last accessed on 24. 4. 2024). Lawton, G. Title: Generative AI ethics: 8 biggest concerns and risks. URL: https://www.techtarget.com/searchenterpriseai/tip/Generative-AI-ethics-8-biggest-concerns (Last accessed on 4. 6. 2024). Majumder, S. Title: Top generative AI industry applications: an in-depth look. URL: https://www.turing.com/resources/generative-aiapplications#understanding-generative-ai (Last accessed on 23. 4. 2024). NVIDIA. Title: Generative AI. URL: https://www.nvidia.com/en-us/glossary/generative-ai/ (Last accessed on 20. 4. 2024). Pogla, M. Title: Artificial intelligence vs human intelligence. URL: https://autogpt.net/artificial-intelligence-vs-human-intelligence/ (Last accessed on 4. 6. 2024). ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Lovro Frece Jure Ahtik Faculty of Natural Sciences and Engineering and Engineering University of Ljubljana University of Ljubljana Snežniška 5 Snežniška 5 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia Graphic Arts and Design Graphic Arts and Design Faculty of Natural Sciences Department of Textiles, Department of Textiles, +386 1 200 32 86 jure.ahtik@ntf.uni-lj.si +368 70 753 650 lovro.frece@gmail.com 326 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION ENGAGING THE SENSES: A STUDY OF SYNESTHETIC DESIGN IN MOTION GRAPHICS Jesenka Pibernik1, Jurica Dolić1, Marta Jagačić1 and Filip Cvitić1 1 University of Zagreb, Faculty of Graphic Arts, Croatia Abstract: This empirical investigation examines synesthetic design principles in motion graphics, exploring how sensory and emotional dimensions interact to create cohesive visual communication. Through an experimental design involving 37 participants, the study analyzed five animated sequences depicting fluid movements in red and blue color variations, utilizing an online survey methodology to assess multimodal perceptual responses. The research employed quantitative analysis to investigate how color, motion, and sound collectively influence viewers’ percep-tions of temperature, emotional tone, speed, and strength associations. Statistical findings revealed significant correlations between chromatic variations and perceptual interpretations, demonstrating that specific animation elements can strategically modulate sensory experiences. Color demonstrated substantial impact on thermal and emotional perception, while movement dynamics substantially influenced interpretations of velocity and energetic potential. By providing empirical evidence of cross-modal sensory interactions, this study contributes insights to perceptual psychology and motion graphic design, offering an understanding how designers can more effectively engage multiple sensory channels to enhance visual communication and emotional resonance. Keywords: synesthetic design, motion graphics, senses, animations. 1. INTRODUCTION Synesthesia, an uncommon neurological condition, is characterized by the involuntary elicitation of an additional perception—such as color—triggered by a primary stimulus characteristic, such as shape. This phenomenon serves as a foundational concept for understanding synesthetic design. Synesthetic design represents an approach that explores and integrates the interconnectedness of multiple sens-es throughout the design process. This methodology aims to unify matter, shape, and content in a manner that appeals to diverse sensory modalities, thereby providing users with a multi-sensory experience (Hubbard, 2007). The focus extends beyond merely creating multisensory experiences; it encompasses a comprehensive under-standing and harmonization of the relationships among different sensory attributes of a product or artifact (Van Campen, 2010.). This involves examining how various sensory qualities—such as sight, sound, touch, taste, and smell—can interact and complement one another to create a cohesive experience. Designers function as manipulators of the senses, working with various stimuli to achieve mutual harmony among them and evoke the human experience of reality. As articulated by Haverkamp, these intuitive strategies are grounded in cross-modal analogy, association, and symbolism that facilitate connections between the senses and enhance interpretability for users (Haverkamp, 2013). A critical indicator of successful synesthetic design in motion graphics is its imperceptibility to the observer. The essence of this design lies in the harmonious synergy of sound, color, and movement, wherein none of these elements should dominate or distract from the primary message (Anceschi, 2000). Design, by its nature, appeals to our senses, which makes any kind of interaction and experience with a product unique and subject to further interpretation (Merter, 2017). Therefore, in developing high-quality synesthetic design, adherence to fundamen- 327 29–30 May 2025, Ljubljana, Slovenia tal principles established through various scholarly studies is imperative. These principles include the judicious use of colors to elicit desired emotional responses, the harmonious integration of visual and auditory stimuli, and well-researched connections between colors and tastes (Spence, 2010). The importance of the product expe-rience resulting from the interplay of senses demands for the development of new qualitative and quantitative research methods. The objective of this paper is to ascertain whether it is feasible to define a set of principles that accurately encapsulates formal elements, synesthetic possibilities, and animation techniques. 2. EXPERIMENTAL To understand the interplay between sound, color, motion, and sensory attributes we made a breakdown of the key parameters and considerations for analysis: • Colors: Red and blue were chosen as the two liquids. These colors are often associated with specific psychological and cultural meanings. • Animation: The movement of the liquids illustrated five distinct fluid movements—stillness, rain, pouring, dripping, and splattering • Sound: how well the sound matches the graphics in animations, as well as their descriptions of the pitch of the sound. Among the eighteen animations shown to participants, ten featured identical soundscapes while eight were differentiated by four higher tones and four lower tones. 2.1 Materials To investigate this relationship, five animations depicting different fluid movements were created to assess their impact on subjects’ multimodal perception (Table 1.). Each of five types of animations was designed in two colors: blue (B) and red (R). Then, different type of sound was added, suggesting the natural sound of flow. The pitch of sound was varied for still water and spraying. Table 1: Stimuli (Animated Liquids): H- higher pitch of sound, L- lower pitch of sound Animation type/sound Link to animation 1. Still liquid/ Sound beneath B1 https://youtu.be/nb_UdkfmFCM the sea surface R1 https://youtu.be/jDeJ-e3kpu4 B1-H https://youtu.be/K43dqfkEkAs B1-L https://youtu.be/Ks-X6Cb2COg R1-H https://youtu.be/GZwoE7oUA4M R1-L https://youtu.be/-Lmxe1c5tQI 2. Rain/ The sound of rain B2 https://youtu.be/JNS3e1fquSQ R2 https://youtu.be/v7wQOqaFTsM 3. Poring liquid/ Pouring sound B3 https://youtu.be/-UDKqniKEec R3 https://youtu.be/aTNVCMaJS3I 4. Dripping/ Dripping sound B4 https://youtu.be/jCwDDfNBH60 R4 https://youtu.be/VmkXa5mFCE4 5. Spraying/ Liquid splash B5 https://youtu.be/WOk7JbhGU28 R5 https://youtu.be/y6S8M10TzvE B5-H https://youtu.be/Ke5Ab4AglA0 B5-L https://youtu.be/ABxaqb5VLgo R5-H https://youtu.be/2ln0Q4uryiA R5-L https://youtu.be/Bzz_kcgsJ1k 328 29–30 May 2025, Ljubljana, Slovenia 2.2 Methods The study examined the interconnections among hearing and sight, within the context of motion graphics experi-ences. The subjects comprised a randomly selected group representing diverse ages, educational backgrounds, and cultural contexts. The experiment included a total of 37 participants: 22 from Croatia and 15 from other countries. Of the participants, 64.8 % (24) were bachelor and graduate students, 10.8 % (4) were postgraduate students, and 23.3 % (9) were employees. The total sample was comprised of 21,6 % male and 78.4 % female participants. Conducted via an online survey divided into two sections, the study aimed to determine how spe-cific aspects of animation influenced viewer’s experience. The first section’s aim was to determine experience of sound related to the color and animation type, the second section’s aim was related to the emotional perception and liquid’s characteristic perception. The order of animation presentation was randomized for each respon-dent. The study combined forced-choice tasks (for perceived speed, strength, relaxation, and attractiveness) with scaled-response tasks (for sound, hardness, and warmth). 3. RESULTS WITH DISCUSSION 3.1 The sound matches the graphics of the animation The first part of the research focused on participants’ perceptions of how well the sound matches the graphics in animations (Table 2.), as well as their descriptions of the pitch of the sound (Table 3.). The data is divided into two sections: 1. Participants rated how well the sound matched the graphics using a Likert scale (1 = completely agree, 5 = completely disagree). Table 2: Sound-Graphics Match. Animation Higher pitch of sound AS SD Lower pitch of sound AS SD still liquid B1-H 2,03 0,87 B1-L 2,16 1,12 R1-H 2,89 1,17 R1-L 2,46 1,04 spraying B5-H 2,08 1,23 B5-L 2,00 1,31 R5-H 2,14 2,14 R5-L 1,97 1,26 Participants perceived the match between sound and graphics differently depending on the color of the liquid and the pitch of the sound. Blue liquids were generally perceived as a better match for higher-pitched sounds in still liquid animations, while red liquids were perceived as a better match for lower-pitched sounds across all animations. 2. Participants described the pitch of the sound in the animations (1 = low, 5 = high). Table 3: Pitch Description. Blue liquids AS SD Red liquids AS SD still liquid B1 1,49 0,73 R1 1,54 0,73 rain B2 3,38 0,89 R2 3,57 0,80 poring liquid B3 3,57 0,77 R3 3,49 0,96 dripping B4 3,46 1,22 R4 3,46 1,12 spraying B5 3,65 0,79 R5 3,51 0,90 sum 15,55 15,57 329 29–30 May 2025, Ljubljana, Slovenia Still liquid animations were associated with low-pitched sounds, while dynamic animations (rain, pouring, dripping, spraying) were associated with moderately high-pitched sounds. Slight variations in pitch ratings were observed based on the color of the liquid. 3.2 Type of animation and color associations The second part of research compared participants’ perceptions of two animated liquids: red and blue. The attri-butes were: perceived speed (Table 4.), strength (Table 5.), relaxation (Table 6.), and attractiveness (Table 7.). The participants had to choose which one was perceived as quicker, stronger, more relaxed, and more attractive. Table 4. Perceived speed Animation Blue liquids points Red liquids points I don‘t see the difference. rain B2 12 R2 7 18 poring liquid B3 11 R3 6 20 dripping B4 3 R4 8 26 spraying B5 14 R5 13 20 sum 30 34 84 Table 5. Perceived strength Animation Blue liquids points Red liquids points I don‘t see the difference. still liquid B1 9 R1 13 15 rain B2 10 R2 10 17 poring liquid B3 15 R3 7 15 dripping B4 6 R4 9 22 spraying B5 13 R5 6 18 sum 29 47 72 Table 6. Perceived relaxation Animation Blue liquids points Red liquids points I don‘t see the difference. still liquid B1 25 R1 6 6 rain B2 20 R2 8 9 poring liquid B3 20 R3 7 10 dripping B4 13 R4 8 16 spraying B5 24 R5 6 7 sum 89 27 32 330 29–30 May 2025, Ljubljana, Slovenia Table 7. Perceived attractiveness Animation Blue liquids points Red liquids points I don‘t see the difference. still liquid B1 19 R1 11 7 rain B2 23 R2 8 6 poring liquid B3 24 R3 6 7 dripping B4 25 R4 6 6 spraying B5 20 R5 11 6 sum 86 36 26 To determine if the preferences for red vs. blue are statistically significant for each attribute, we used chi-square test. The chi-square test revealed statistically significant differences in participants’ preferences for red vs. blue liquids across all attributes. Blue is strongly associated with calmness and attractiveness, while red is slightly pre-ferred for perceived speed and strength. The “I don’t see the difference” option was frequently chosen, indicating that some participants did not perceive a clear distinction between the two colors for certain attributes (Table 8.). Table 8. Preferences for red vs. blue liquids across all attributes Attribute Blue Liquids Red Liquids I Don’t see the Total Chi-Square Difference Perceived Speed 30 34 84 148 χ2=36.71, p<0.05 Perceived Strength 29 47 72 148 χ2=18.84, p<0.05 Calmness 89 27 32 148 χ2=48.60, p<0.05 Attractiveness 86 36 26 148 χ2=42.07, p<0.05 Additionally, the participants performed scaled-response tasks. They rated the hardness (1=soft, 5=hard) (Table 9.) and warmth (1=warm, 5=cold) (Table 10.) of the same animated liquids. Table 9. Hardness ratings Animation blue AS SD red AS SD still liquid B1 2,11 1,05 R1 2,22 1,00 rain B2 2,43 1,14 R2 3,24 1,30 poring liquid B3 2,11 1,13 R3 2,08 0,98 dripping B4 2,05 1,18 R4 2,59 1,19 spraying B5 3,14 1,27 R5 2,05 1,20 sum 11,84 12,18 331 29–30 May 2025, Ljubljana, Slovenia Table 10. Temperature ratings Animation blue AS SD red AS SD still liquid B1 4,16 1,17 R1 2,19 1,35 rain B2 4,22 1,11 R2 2,59 0,93 poring liquid B3 3,81 1,20 R3 2,57 1,07 dripping B4 3,59 0,98 R4 2,41 1,01 spraying B5 3,89 0,77 R5 2,49 1,19 sum 19,67 12,25 To analyze the data provided in the Likert-scale responses for hardness and warmth, we performed paired t-tests (if the data meets the assumptions of normality). We also calculated effect sizes using Cohen’s d to assess the magnitude of the differences between red and blue liquids. • Hardness: Red liquids are perceived as harder in some conditions (rain, dripping), while blue liquids are perceived as harder in others (spraying). • Warmth: Blue liquids are consistently perceived as colder than red liquids across all conditions, with large effect sizes. By performing these analyses, we can conclude that there are significant differences in how participants perceive the hardness and warmth of red and blue liquids, with warmth showing a stronger and more consistent effect. To find out more whether participants’ preferences for red or blue liquids are correlated with their ratings of hardness and temperature we performed a correlational analysis and a subgroup analysis of the data obtained by forced choice and Likert scale methods. The results suggested that color preferences influence participants’ perceptions of hardness and temperature, but the relationships are relatively weak. Hardness perceptions are sig-nificantly influenced by color preferences. Participants who prefer a particular color tend to perceive liquids of that color as harder. The regression analysis reveals that temperature perceptions may be less strongly influenced by color preferences compared to hardness perceptions. These findings suggest that color preferences play a stronger role in shaping perceptions of hardness compared to temperature. Further research with a larger sample size and additional variables could provide more robust insights. 4. CONCLUSIONS Our research unveils the intricate relationships between sound, color, and liquid animation dynamics, challenging simplistic perceptual mapping theories. The study demonstrates that color-sound associations are profoundly context-dependent, with blue liquids consistently linked to calmness and higher-pitched sounds in still anima-tions, while red liquids correlate with warmth, strength, and lower-pitched sounds. Movement type significantly modulates these perceptual interpretations, revealing that slower animations emphasize hardness and controlled characteristics, whereas faster, more chaotic movements blur traditional color-attribute associations. Notably, spraying animations represent a perceptual “neutral zone” that challenges established categorizations. The re-sults suggested that color preferences influence participants’ perceptions of hardness and temperature, but the relationships are relatively weak. These findings contribute to our understanding of cross-modal perception of animated liquids, suggesting that sensory experiences are more fluid and interconnected than previously understood. By illuminating how sound pitch, color, and animation dynamics interact, the research provides valuable insights for design, user experience, and cognitive psychology, highlighting the sophisticated, non-linear ways in which humans interpret sensory infor-mation. While providing significant insights, the study acknowledges the need for further investigation into: cultural variations in color-sound perception, neurological mechanisms underlying these cross-modal associations and potential. 332 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Anceschi G., Riccò D. (2000.) Research of Communication Design: a synesthetic approach, URL: https://www.researchgate.net/profile/Dina-Ricco/publication/265655354_Research_of_Communication_Design_a_synesthetic_approach/links/5444da470cf2e6f0c0fbd0ea/Research-of-Communication-Design-a-synesthetic-approach.pdf (last accessed on 28. 11. 2024) Haverkamp M. (2013.) Synesthetic design; Handbook for a multisensory approach, Birkhäuser, Basel. Hubbard E. M. (2007.) Current Psychiatry Reports; Neurophysiology of synesthesia, vol. 9., no. 3., 193 – 199., URL: https://doi.org/10.1007/ s11920-007-0018-6 (last accessed on 28. 11. 2024) Merter S. (2017.) Synesthetic approach in the design process for enhanced creativity and multisensory experiences, URL: https://www. tandfonline.com/doi/pdf/10.1080/14606925.2017.1352948 (last accessed on 22.05.2024.) Spence C. (2019.) On the relationship(s) between color and taste/flavor, URL: https://econtent.hogrefe.com/doi/full/10.1027/1618-3169/ a000439 (last accessed on 28. 11. 2024) Van Campen C. (2010.) The hidden sense: Synesthesia in art and science, The MIT Press, London. ADDITIONAL DATA ABOUT AUTHORS Corresponding author Co-author(s): Department for graphic New Media Design RIT Croatia design and imagining Jesenka Pibernik Jurica Dolić Faculty of Graphic Arts Don Frana Bulića 6 University of Zagreb jurica.dolic@croatia.rit.edu 20000 Dubrovnik, Croatia Getaldićeva 2 10 000 Zagreb Marta Jagačić Faculty of Graphic Arts jesenka.piberni@grf.unizg.hr Getaldićeva 2 10 000 Zagreb +385996067669 University of Zagreb mar.jagacic@gmail.com Filip Cvitić Department for graphic design and imagining Faculty of Graphic Arts University of Zagreb Getaldićeva 2 10 000 Zagreb +385915593064 filip.cvitic@grf.unizg.hr 333 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION EXPLORING AI-DRIVEN PERSONALISATION FOR EMOTIONAL DESIGN: THE IMPACT OF CUSTOM CONTENT ON EMOTIONAL CONNECTION Neda M. Keresteš1, Tanja Radovanović2, Ivana Tomić1, Sandra Dedijer1, Magdolna Pal1, Jelena Kerac1 and Gala Golubović1 1University of Novi Sad, Faculty of Technical Sciences, Serbia 2 University of Montenegro, Institute for Interdisciplinary and Multidisciplinary Studies, Montenegro Abstract: The paper investigates how three personalisation strategies influence user emotional response, satis-faction, and privacy concerns. We experimented with three conditions: (A) Minimal personalisation, (B) Relevant preference-based personalisation, and (C) Extended personalisation with a feedback option. In a within-subjects design, 28 participants interacted with tailored suggestions. The SAM (Self-Assessment Manikin) and post-treat-ment questionnaires were used to measure the emotional responses. Findings suggest that Version C led to the most satisfaction and engagement whilst reducing discomfort compared to Version B, although extended personalisation also amplified privacy concerns. The study also highlights the critical role of digital literacy and AI experience, showing that users with greater familiarity with AI tools are more open to sharing data and reporting better overall experiences. These findings underscore the importance of balancing personalisation with user con-trol and algorithm transparency to optimise AI-driven systems while addressing risks such as filter bubbles and privacy-related anxiety. Keywords: mass personalisation, emotion design, AI-driven design, user experience 1. INTRODUCTION Emotional design, one of the fundamental concepts underlying user experience, has been explored through the psychological and emotional aspects of user interaction with the interface. Norman (2004) defines emotional de-sign as a tool that evokes positive emotional states, while Hassenzahl and Tractinsky (2011) highlight its ability to enhance users‘ perceptions of a system‘s usefulness. Desmet and Hekkert (2007) offer a framework for analysing product experience, considering three dimensions: affective, cognitive, and behavioural. These studies indicate a shift from the previous emphasis on functionality toward a more holistic approach that integrates users‘ emotional and mental needs. In the context of mass personalisation, Tseng and Jiao (2001) define mass customisation as constrained combi-nations of predetermined choices, whereas Kumar (2007) emphasises that generative AI has enabled real-time, data-driven individualisation. Zhou, Ji, and Jiao (2013) further develop this concept by stressing the importance of emotional patterns in designing personalised interfaces. Real-world examples include Spotify, which leverages AI to generate customised playlists, and Netflix, whose algorithms recommend content based on viewing history, showcasing the practical application of these ideas. The ethical concerns of mass personalisation have been widely studied. The privacy–personalisation paradox, explored by Awad and Krishnan (2006), reveals that users simultaneously seek personalisation while fearing data exploitation. Acquisti, Brandimarte, and Loewenstein (2015) further suggest that increased privacy awareness can heighten resistance to personalisation, even when it enhances user experience. Additional phenomena, such as algorithm aversion (Dietvorst et al., 2015) and overtrust (Buçinca et al., 2021), highlight the complex relation-ship between users and AI, while the risks of filter bubbles and echo chambers (Flaxman et al., 2016) point to the dangers of limited information diversity. Ribeiro, Singh, and Guestrin (2016) examine the trade-offs between ex-plainability and algorithmic accuracy, emphasising the need for transparency in personalised recommendations. Although extensive research exists on emotional design and AI-driven personalisation, a notable gap exists in 334 29–30 May 2025, Ljubljana, Slovenia exploring their synergy, particularly from an ethical perspective. For example, the impact of different personalisa-tion modalities on affective connection and the long-term implications of intrusive data collection are still unclear. These gaps highlight the need for an interdisciplinary approach integrating design, ethics, and technological ad-vancements. The main objective of this study is to examine the effect of personalisation level on user satisfaction, level of en-gagement, and subjective discomfort. The study also investigates the impact of greater control over recommen-dations on the general level of user experience. From this, the following fundamental questions emerge: RQ1: How does the emotional reaction of users change while moving from minimal to intensive personalisation? RQ2: How does the perceived discomfort result from increased personalisation level? RQ3: How does the ability to change recommendation types or request alternative content affect user satisfaction and potentially mitigate the filter bubble effect? RQ4: How do digital literacy and prior experience with AI tools influence users‘ openness to sharing personal data, their engagement with recommendation systems, and their overall user experience? These questions relate to the privacy–personalisation paradox and related phenomena under emotional design, including algorithm aversion and overtrust in AI systems. The study also examines whether greater transparency, showing users recommendations beyond their usual preferences, and introducing a feedback mechanism can reverse the risks of creating „bubbles“ (filter bubble/echo chamber). The answers to these questions are expected to indicate the optimal balance between personalisation level and adequate user control over recommendations while easing users‘ discomfort and ensuring content variety. 2. METHOD 2.1 Participants The experiment involved 28 participants (17 women and 11 men), all university graduates aged between 24 and 41. They reported extensive use of web and mobile applications, which aligned with a high average self-asses-sment of digital literacy (M = 4.57 on a 1–5 scale). However, their experience with AI tools such as ChatGPT and Gemini was comparatively lower (M = 3.6 on a 1–5 scale). Participants were informed about data usage and privacy measures and could withdraw from the study anytime. 2.2 Test environment A specialised Custom GPT was developed using a paid ChatGPT Plus subscription, featuring: - custom instructions governing the experimental flow and data handling, ensuring that all data would be erased after the study, - an internal knowledge base designed to generate brief personalised messages and recommendations for each experiment version and - privacy safeguards to ensure that personalised content was stored only during the experiment and per- manently deleted afterwards. The Custom GPT was instructed to address users by name, maintaining a casual and friendly tone, with optional emojis or icons (see Figure 1). The study explores three levels of personalisation—Version A, B, and C—to assess how varying degrees of cus-tomisation and user control impact emotional responses, satisfaction, and perceptions of fairness. Version A offers minimal personalisation, addressing users by name but providing only generic recommendations based on demographic data. This approach tests whether basic personalisation cues, like name recognition, can generate positive emotional responses without deeper customisation. Version B introduces a more relevant personalisation level by incorporating demographic and preference data. Recommendations are explicitly linked to user history (e.g., „Because you watched X, we think you would enjoy Y“), which helps reduce the „black box“ effect, enhancing both trust and relevance. Version C builds upon Version B by integrating feedback mechanisms and allowing users to explore alternative 335 29–30 May 2025, Ljubljana, Slovenia recommendation categories (e.g., sports events, concerts). Users receive prompts like, „Would you like more of these or completely different suggestions?“ This version emphasises transparency and user control to address privacy concerns and reduce discomfort associated with excessive personalisation. Figure 1: The Custom GPT training flow 336 29–30 May 2025, Ljubljana, Slovenia 2.3 Experiment Design The experiment‘s flow, presented in Figure 2, had the following steps: 1. Pre-Survey After reading and accepting the consent form, participants completed a pre-survey to pro-vide demographic information, including their ID, age (24–42), frequency of using persona-lised apps (TehUsage, 1–5 scale), and self-assessed AI knowledge (AISkill, 1–5 scale). Following this, GPT collected detailed user preferences, such as weekend activities, leisure routines, entertain-ment habits, favourite movies, directors, actors, musicians, podcasts, and news sources. 2. Presentation of Each Version (A, B, C) For each level of personalisation (A, B, and C), participants were presented with three recommen-ded items across different categories, including music/podcasts, films/books, and weekend events. They spent approximately 2–3 minutes reviewing each set of recommendations. 3. Post-Treatment (Per Version) Survey After viewing each version‘s recommendations, participants completed a short post-treatment questionnaire, which included: • The Self-Assessment Manikin (SAM) (Bradley & Lang, 1994) to measure: o Valence (1 = very unpleasant, 5 = very pleasant) o Arousal (1 = calm, 5 = excited) • Satisfaction Measure (1–5 Likert Scale): o “I am satisfied with the recommendations I just received.” • Discomfort Measure (1–5 Likert Scale): o “I felt uneasy during these recommendations.” The order of personalisation levels (A, B, and C) was randomised to prevent sequence bias. 4. Final (Post-Experiment) Questionnaire The final questionnaire was divided into three sections: • User Experience Questionnaire (UEQ-S): A short version with eight items, each rated on a 1–7 scale using pairs of opposite adjectives: o Unclear (1) – Clear (7) o Clumsy (1) – Graceful (7) o Unreliable (1) – Reliable (7) o Conventional (1) – Innovative (7) o Boring (1) – Exciting (7) o Unattractive (1) – Attractive (7) o Not entertaining (1) – Entertaining (7) o Demotivating (1) – Motivating (7) • Privacy & Data Sharing Items (1–5 Likert Scale), adapted from IUIPC (Malhotra, Kim & Agarwal, 2004) and the privacy-personalisation paradox (Awad & Krishnan, 2006), including statements such as: o “I believe using my data for this type of personalisation is justified.” o “I am willing to share my data in the future for better recommendations.” o “I would like more control over which data is used for generating recommendations.” • Open-Ended Questions: o “Which level of personalisation did you find most pleasant and why?” o “Which one irritated or bothered you the most?” 337 29–30 May 2025, Ljubljana, Slovenia Figure 2: The experiment design 338 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS AND DISCUSSION The collected data was organised into a CSV file with the following columns: • Demographic & pre-study data: o TehUsage – Frequency of using personalised applications (1–5 scale) o AISkill – Self-assessed AI knowledge (1–5 scale) • Post-treatment data (Per Version A, B, C): o A_Val, A_Aro, A_Sat, A_Dis – Valence, Arousal, Satisfaction, and Discomfort scores for Version A o B_Val, B_Aro, B_Sat, B_Dis – Corresponding scores for Version B o C_Val, C_Aro, C_Sat, C_Dis – Corresponding scores for Version C • User Experience Questionnaire (UEQ-S) items: o UEQ1 – UEQ8 – Responses to the 8-item short version of the UEQ • Privacy Concerns Responses: o PC1, PC2, PC3 – Likert scale responses to privacy and data-sharing statements • Open-Ended Responses: o Open1, Open2 – Responses to the two open-ended questions A repeated-measures ANOVA was conducted to analyse the effects of the three versions (A, B, and C) on four dependent variables: valence, arousal, satisfaction, and discomfort. All measures were averaged across three scenarios to provide reliable estimates of version effects. Valence Ratings A significant main effect of version was found: F(2, 54) = 9.61, p < .001, η²ᵧ = .089. Post-hoc comparisons using Bonferroni correction revealed: Version C (M = 4.81, SD = 0.21) elicited significantly higher valence ratings than Version A (M = 4.54, SD = 0.46, p = .002) and Version B (M = 4.68, SD = 0.38, p = .040). Practically, Version C is shifting users from a neutral ‐ple-asant to a pleasant experience on the 5‐point scale. Arousal Ratings Mauchly‘s test indicated a violation of sphericity (W = 0.76, p = .028), so Greenhouse-Geisser corrections were applied (ε = 0.81). The analysis revealed a significant main effect of version: F(2, 54) = 30.87, p < .001, η²ᵧ = .183. Post-hoc comparisons showed that: Version C (M = 4.40, SD = 0.42) and Version B (M = 4.26, SD = 0.43) both induced significantly higher arousal than Version A (M = 3.90, SD = 0.50, p < .001 for both). Version C also aroused substantially higher arousal than Version B (p = .034). This significant effect shows that the richer, interactive feed in Version C grabs attention far more effectively. Satisfaction Ratings A significant main effect of the version was observed: F(2, 54) = 25.06, p < .001, η²ᵧ = .150. Post-hoc analyses revealed: Version C (M = 4.82, SD = 0.31) and Version B (M = 4.69, SD = 0.42) resulted in significantly higher satisfaction than Version A (M = 4.42, SD = 0.49, both p < .001). The difference between Version B and Version C was close to but did not reach statistical significance (p = .056). A 0.40point jump (1–5 scale) from A to C is practically the difference between “mostly satisfied” and “very satisfied.” Discomfort Ratings A significant main effect of the version was found: F(2, 54) = 5.48, p = .007, η²ᵧ = .041. Post-hoc comparisons showed: Version B (M = 1.88, SD = 0.32) induced significantly higher discomfort than Version C (M = 1.70, SD = 0.41, p = .010). Although significant, the absolute gap (≤0.18/5) is small; Version C’s transparency almost erases the discomfort spike in Version B. With η²=.041, the absolute effect is mild, so designers should monitor discomfort qualitatively, not rely solely on mean scores. Version A (M = 1.74, SD = 0.41) did not significantly differ from either B or C (all p > .093). 339 29–30 May 2025, Ljubljana, Slovenia Correlation Analysis All correlations were statistically significant at p < 0.001, showing robust positive linear relationships between participants‘ pre-survey scores and post-experiment evaluations (Figure 3). For DIG_LIT (Digital Literacy Score), the strongest correlations were with UEQ1 (r = 0.805) and UEQ4 (r = 0.731). For AI_EXP (AI Experience Score), even stronger correlations were found (e.g., UEQ4: r = 0.913, UEQ1: r = 0.904). Practically, each extra point of digital literacy directly boosts perceived UX quality. Figure 3: Correlation matrix between pre-survey and post-survey measures RQ1: How does the emotional reaction of users change while moving from minimal to intensive personalisation? Version C (extended personalisation with feedback) received the highest ratings for satisfaction and engagement without significantly increasing discomfort. This suggests that richer personalisation enhances user experience. However, some users reported increased discomfort when they realised the system „knew more“ about them (Versions B and C). In practice, even modest feedback integration (Version C) upgrades the experience from “useful” to “desirable” without a parallel rise in discomfort. RQ2: How does the perceived discomfort result from increased personalisation level? Greater personalisation and data access increased discomfort, especially in Versions B and C. This aligns with the privacy–personalisation paradox, where users appreciate relevant recommendations but feel uneasy about how their data is used (Awad & Krishnan, 2006). Notably, Version C caused less discomfort than Version B, im-plying that transparency and feedback mechanisms help reduce user anxiety (Ribeiro, Singh & Guestrin, 2016). RQ3: How does the ability to change recommendation types or request alternative content affect user satisfaction and potentially mitigate the filter bubble effect? When it comes to user control over recommendations (RQ3), participants responded positively to features such as „show something else“ and „I do not like this recommendation.“ These findings align with research on algorithm aversion (Dietvorst et al., 2015), highlighting that giving users the ability to influence content selection and correct AI-generated suggestions enhances perceptions of fairness and engagement (Buçinca et al., 2021). Additionally, introducing alternative recommendations in Version C—offering content outside users‘ typical pre-ferences—appears promising in mitigating the filter bubble effect. By exposing users to a more diverse range of content, Version C not only enhances satisfaction but also reduces the likelihood of users being trapped in narrow informational „bubbles.“ The discomfort values were very low (between 1.70 and 1.88 on a scale of 1 to 5), which can be explained by the fact that the participants knew that the algorithm used only the data that they had previously entered voluntarily in the pre-survey experiment part. RQ4: How do digital literacy and prior experience with AI tools influence users‘ openness to sharing personal data, their engagement with recommendation systems, and their overall user experience? Users with higher digital literacy and AI experience rated personalised systems more positively in clarity, reliability, and satisfaction. These users were also more open to sharing personal data, agreeing with statements like „Using my data for personalisation is justified“ and „I am willing to share data for better recommendations.“ This suggests that familiarity with AI fosters trust in data-driven personalisation. 340 29–30 May 2025, Ljubljana, Slovenia However, even among these users, there was a strong preference for control over data usage, reinforcing con-cerns about the privacy–personalisation paradox. The statement „I would like more control over which data is used for recommendations“ received strong agreement, emphasising the need for transparent and user-control-led personalisation systems. The within-subjects design allowed participants to experience all three levels of personalisation, strengthening statistical power and clarifying the privacy–personalisation paradox in emotional design. However, the small sam-ple size (28 participants) and short-term exposure limit the robustness of findings. Future studies should expand demographic diversity and increase interaction time with AI systems to assess long-term effects like habituation and shifts in privacy attitudes. Furthermore, considering the spotted connection between algorithm transparency and level of discomfort, future studies should consider the scenarios where participants do not know what data was used for training the AI model. 4. CONCLUSION The study results emphasise balancing personalisation depth with user control and transparency. As observed in Version C, which offered the most expansive personalisation and feedback mechanisms, users expressed higher satisfaction and engagement when given more control over the system. However, these benefits come with an increased need to address privacy concerns and discomfort, suggesting an optimal mix of personalisation levels and transparency to enhance the overall experience. Furthermore, the research highlights the importance of digital literacy and AI experience in determining user openness to sharing information and interacting with the re-commendation system. These insights contribute to a deeper understanding of how AI-driven personalisation can be optimised to create positive user experiences while alleviating risks such as filter bubbles and privacy-related anxiety. 5. ACKNOWLEDGMENTS This research has been supported by the Ministry of Science, Technological Development and Innovation (Con-tract No. 451-03-137/2025-03/200156) and the Faculty of Technical Sciences, University of Novi Sad, through project „Scientific and Artistic Research Work of Researchers in Teaching and Associate Positions at the Faculty of Technical Sciences, University of Novi Sad 2025“ (No. 01-50/295). 341 29–30 May 2025, Ljubljana, Slovenia 6. 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J. 2013. „Affective and Cognitive Design for Mass Personalization: Status and Prospect.“ Journal of Intelligent Manufacturing 24(5): 1047–1069. https://doi.org/10.1007/s10845-012-0673-2 342 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Engineering and Design Engineering and Design Cetinjski put 2 Faculty of Technical Sciences Faculty of Technical Sciences 81000 Podgorica, Montenegro University of Novi Sad University of Novi Sad Trg Dositeja Obradovića 6 Department of Graphic MARDS Reforming PHD studies Department of Graphic University of Montenegro Neda Milić Keresteš Tanja Radovanović Magdolna Pal Trg Dositeja Obradovića 6 tanjaradovanoviic@gmail.com 21000 Novi Sad, Serbia 21000 Novi Sad, Serbia apro@uns.ac.rs Ivana Tomić milicn@uns.ac.rs Department of Graphic Jelena Kerac Engineering and Design Department of Graphic Faculty of Technical Sciences Engineering and Design University of Novi Sad Faculty of Technical Sciences Trg Dositeja Obradovića 6 University of Novi Sad 21000 Novi Sad, Serbia Trg Dositeja Obradovića 6 tomic@uns.ac.rs 21000 Novi Sad, Serbia jelena.kerac@uns.ac.rs Sandra Dedijer Department of Graphic Gala Golubović Engineering and Design Department of Graphic Faculty of Technical Sciences Engineering and Design University of Novi Sad Faculty of Technical Sciences Trg Dositeja Obradovića 6 University of Novi Sad 21000 Novi Sad, Serbia Trg Dositeja Obradovića 6 dedijer@uns.ac.rs 21000 Novi Sad, Serbia gala@uns.ac.rs 343 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION ANALYSIS OF THE RELEVANCE AND APPEAL OF THE VISUAL PRESENTATION OF MEAT PRODUCTS GENERATED USING ARTIFICIAL INTELLIGENCE Lucija Brina Arvaj1, Tatjana Šubic2 and Jure Ahtik1 1Faculty of Natural Sciences and Engineering, Slovenia 2Biotehniški center Naklo, Slovenia Abstract: Meat and meat products play a crucial role in a balanced diet, with consumers relying heavily on visual appeal. This study examines the accuracy of generative AI in the visualisation of meat products, hypothesising that AI-generated images cannot yet replace real photographs. Images of various meat products were created using Adobe Firefly 3 and evaluated by food technology professionals. The survey results show that AI-generated images of commonly advertised products such as burgers (82% approval) and prosciutto (67% approval) were relatively accurate, while complex products such as mortadella (9% approval) and beef tartare (19% approval) were considered unrealistic in terms of colour, texture and composition. The most common problems included ina-ccurate colour representations, cross-section details and plate arrangement. The results highlight the limitations of artificial intelligence in professional food photography and emphasise the need for skilled photographers. While AI can create visually appealing images, its lack of accuracy makes it unsuitable for demanding applications in the food industry. Future advancements may enhance AI’s reliability, but until then, professional photography remains essential for precise representation of meat products. Keywords: artificial intelligence, meat products, food industry, food photography, visual presentation 1. INTRODUCTION Meat and meat products are essential for a balanced diet (NIJZ). As consumers rely heavily on visual appeal when buying, sensory perception plays an important role. Generative AI, which is increasingly being integrated into everyday life, enables users to create images, videos and code based on text prompts. Research focuses primarily on the distinction between AI-generated images and conventional photographs (Misal, 2024). As sensory perception influences food choices, consumers often rely on appearance, especially when they are unfamiliar with a product (Mugge, 2018). This research explores how well generative AI represents meat products. The hypothesis is that AI cannot yet fully replace real images of meat products. The objectives include generating AI images of meat products and assessing their accuracy by surveying food professionals. 1.1. Artificial intelligence The first AI definition dates back to 1955 (John McCarthy), but Elaine Rich later provided a more precise one: “Artificial intelligence is the study of how to make computers do things at which, at the moment, people are bet-ter.” (Ertel, 2024) Early AI systems were rule-based and supported decision-making through expert systems and knowledge bases. AI encompasses various computer algorithms that replicate human intelligence, including pat-tern recognition, language processing, decision making and learning. (Banh, 2023) Machine learning, a central subfield of AI, enables systems to learn from data and improve their performance over time. (Janiesch, 2021) It includes unsupervised learning (finding patterns in unlabelled data), supervised learning (training on labelled data for predictions) and reinforcement learning (learning by interacting with the environment). (Banh, 2023) 344 29–30 May 2025, Ljubljana, Slovenia Deep learning, a branch of machine learning inspired by the human brain, uses artificial neural networks to pro-cess one-dimensional data such as text, but also high-dimensional data such as images and videos. (Angelova, 2024; Banh, 2023) 1.2. Generative AI Unlike earlier AI, which focused on recognition, generative AI creates new content — text, images, video, sound and code—mimicking human creativity. Its rapid rise since 2022 with ChatGPT-3 has opened up new possibilities, but also raised various concerns about job displacement, etc. (Wessel, 2024) Generative tools such as DALL-E, Stable Diffusion and Adobe Firefly allow users to generate images without much design skills, with Firefly 2 standing out for its realism (Banh, 2023; Angelova, 2024). Adobe Firefly allows users to create images, illustrations and videos by inserting a prompt in over 100 languages and adjusting various settings. It sources data from Adobe Stock, ensuring licensed use (Adobe, 2024). However, despite constant progress, AI still struggles with complex multi-object compositions (Frolov, 2021). Research on AI-generated images focuses more on appeal than accuracy. Studies show that people prefer AI images until they learn their origin, which causes scepticism, especially among older generations (Califano, 2024; Zeleny, 2024). AI also raises ethical concerns, from job loss to data sourcing. Human oversight methods like crowdsourcing and expert-in-the-loop approaches aim to align AI with ethical standards (Kirova, 2023). In graphics, deepfakes pose major risks, violating human rights and spreading misinformation, prompting UNESCO and the EU to establish ethical guidelines (Kirova, 2023). 1.3. Meat as a sales item The role of meat in human nutrition makes the choice of quality crucial (Šubic, 2022). Vision plays a decisive role in the perception of food and influences the first impression through colour, contrast and symmetry (Jelinčić, 2023). The association of colours with objects begins early in our cognitive development. Colour is the most im-portant sensory attribute of food and is often directly related to the perceived quality of a product. (Clydesdale, 1991) Consumers often judge product quality when shopping based on sensory attributes such as smell and appearance. (Šubic, 2022) Colour psychology plays an important role in the food industry. A study from the 1970s found that blue steaks and green fries caused nausea in participants under normal lighting, indicating an instinctive aversion to unnatural food colours (Jahnke, 2018). The appearance of food products is crucial. Certain additives can significantly en-hance their appearance. (Šubic, 2022) Due to various attractiveness factors, photos of meat dishes and products must show appealing, typical and ex-pected shades and colours to attract buyers. 1.4. Food Photography In food photography, composition, lighting and colour are taken into account, with the lighting enhancing the appe-al. In commercial photography, the photographer also edits the image after it has been taken, paying particular attention to the colours to make them more attractive to buyers. Post-processing requires high-quality photos, so photographers need to know the lighting characteristics when taking the images. (Štampfl, 2024). The integration of AI is increasing in the food industry, e.g. in creating recipes and understanding customer pre-ferences. However, despite successful integration, the images generated by AI in this area are still considered unreliable. This is partly due to the high visual standards set by advertising agencies when promoting food. These representations are often heavily edited, creating a gap between reality and expectations. (Ong, 2024) 345 29–30 May 2025, Ljubljana, Slovenia When photographing meat products, in addition to general requirements such as the right lighting, composition and angle, special attention must be given to colour and texture. The meat product should be easily recognisable and meet all quality standards. Evaluating the correct appearance of meat products is a complex process. (Šubic, 2022) 2. EXPERIMENTAL To evaluate the accuracy of AI-generated images of meat products, we implemented a two-stage experimental approach: Image generation and expert evaluation. The aim of the study was to determine whether generative AI can accurately represent various meat products. First, a selection of meat products with distinct sensory properties was made to ensure a diverse evaluation. Adobe Firefly 3 was then used to generate images, which were then evaluated in a survey of the industry profes-sionals based on criteria such as colour, shape, texture and overall presentation. 2.1. Generating images The AI-generated images were generated with Adobe Firefly 3. The prompts were inserted in English with appro-priate wording for various meat products. To achieve optimal results, the images were generated 3-5 times and the prompts for each product were corrected where necessary. 2.2. Survey The survey was conducted on the website 1ka to examine the accuracy of AI-generated images of meat products. We focused on the colour, shape, texture and arrangement of the products on the plate. Our target group were food technology professionals with good eyesight or corrective aids. During the survey, the food technology professionals evaluated the sensory properties of AI-generated images of meat products. Twenty-two suitable people took part in the survey, while four people were excluded due to incor-rect profession or poor eyesight without visual aids. Firstly, respondents determined whether each image was professionally accurate or not. If they considered it un-suitable, they specified the reason why, choosing from colour, shape, cross-section composition, appearance of the plate or a comment of their own. 3. RESULTS WITH DISCUSSION Figs. 1–10 show images of meat products, created with Adobe Firefly 3, that were part of the survey for food industry professionals. Figure 1: AI-generated image of burger Figure 2: AI-generated image of prosciutto 346 29–30 May 2025, Ljubljana, Slovenia Figure 3: AI-generated image of chicken skewers Figure 4: AI-generated image of Wiener Schnitzel Figure 5: AI-generated image of steak Figure 6: AI-generated image of Carniolan sausage Figure 7: AI-generated image of dry salami Figure 8: AI-generated image of hot dog Figure 9: AI-generated image of beef tartare Figure 10: AI-generated image of mortadella 347 29–30 May 2025, Ljubljana, Slovenia Table 1 shows the results of the survey. It includes the percentages of people who rated the images as appropriate or inappropriate, as well as the main issues they found. Table 1: Appropriateness of AI-generated images of meat products number Figure Appropriate Inappropriate Meat product Main issues image image 1 - Colour, Burger 82% 18%- shape. - Colour, 2 Prosciutto 67% 33% - plate appearance, - cross-section. - Colour, 3 - shape, Chicken skewers 59% 41%- plate appearance (too perfect). 4 - Colour, Wiener schnitzel 57% 43%- plate appearance. - Colour, 5 - shape, Steak 50% 50%- cross-section, - plate appearance. - Colour, 6 Carniolan sausage 36% 64% - shape, - missing skewer. - Colour, 7 - shape, Dry salami 29% 71%- cross-section, - too thick slices. - Colour, 8 Hot dog 29% 71% - plate appearance, - artificial casing. - Colour, 9 - texture, Beef tartare 19% 81%- shape, - unrealistic appearance. - Colour, 10 Mortadella 9% 91% - cross-section, - missing fat particles. In Fig. 1, 87% of participants found the burger’s presentation accurate, but 18% criticized the meat patty’s colour and shape. Fig. 2 shows prosciutto, which 33% deemed unsuitable for professional use, citing issues with colour, plate appe-arance, and cross-section composition. In Fig. 3, 41% found the chicken skewers inaccurate, mainly because of their colour, shape, and plate appea-rance. Some commented that they looked “too perfect” and that the colour made them appear as a lower-quality product. Fig. 4 shows a Wiener Schnitzel or breaded veal slice. 57% of experts approved of its presentation, while 43% found the colour and plate appearance unsuitable. 348 29–30 May 2025, Ljubljana, Slovenia Half of the participants considered the steak in Fig. 5 inaccurate, mainly because of its colour and cross-section composition. Additional comments described the image as too perfect and said that slices appeared to be different from the same piece of meat. Fig. 6 depicts Carniolan sausage, which 64% of experts found unsuitable, mentioning colour and shape. Further-more, additional comments mentioned an incorrect look, specifically the absence of the characteristic skewer and a resemblance to grilled sausage. In Fig. 7 and Fig. 8, 71% found the presentations of dry salami and a hot dog unfit for professional use. Dry-cured sausage slices were considered too thick, while the hot dog’s colour and plate appearance were criticized. Al-though the shape of the sausage inside the hot dog was considered correct, some participants found the sausage more appealing when presented in a natural rather than artificial casing. Fig. 9 shows tartare, which 81% deemed inappropriate due to unnatural colour, texture, and an overly smooth, unnatural appearance. Finally, in Fig. 10, 91% found the mortadella inaccurate due to its cross-section composition and colour. Additional comments noted that the lack of characteristic fat particles made it look unnatural. Only 9% considered the image suitable. Bottom of Form 4. CONCLUSION The results of this study highlight the current limitations of generative AI in accurately representing meat products for professional use. While AI-generated images of certain products such as burgers (82% approval) and pro-sciutto (67% approval) were considered relatively suitable, more complicated products such as mortadella (9% approval) and beef tartare (19% approval) were considered inappropriate due to unrealistic colour, texture and composition. The least appropriate images were of meat products that are not as heavily advertised, probably lacking the information about such products. Colour was the most frequently cited issue for several images, especially for products where slight deviations in hue can signal differences in freshness, quality or even edibility. In addition, inaccuracies in the composition of the cross-section and appearance of the plate were frequently noted, emphasising that AI struggles to reproduce the complex structural details of processed and raw meat. The ability to generate visually appealing images does not necessarily translate into accuracy - a crucial aspect in the food industry, where confidence in product presenta-tion is a key factor in purchasing decisions. These findings emphasise the indispensable role of professional photographers. Unlike AI, photographers use their expertise in lighting, composition and post-processing to ensure that meat products are presented in an aesthetically pleasing and realistic way. Photographers are also able to make subtle but crucial adjustments to meet customer needs and industry standards, something AI is currently unable to do. Studies suggest that while AI tools are promising, they cannot yet replace professionally created photographs, but are a cheap solution with slightly lower quality. In addition, AI is not able to produce consistently accurate textures, cross-sections and natural-looking composi-tions, further emphasising the need for human supervision in image creation. As AI continues to evolve, collabora-tion between AI technology and skilled photographers could increase efficiency without compromising authenticity to provide consumers with a reliable and trustworthy visual representation of food. 349 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Adobe Firefly – Free generative intelligence for creators. URL: https://www.adobe.com/products/firefly.html (last accessed on 16. 1. 2025) Angelova N. 2024. “The capabilities of the art-oriented artificial intelligence Adobe Firefly and its visual advantages and disadvantages.” Fundamental Sciences and Applications 30(1):1–10. Banh L, Strobel G. 2023. “Generative artificial intelligence”. Electron Markets 33(1):63. Califano G, Spence C. 2024. “Assessing the visual appeal of real/AI-generated food images.” Food Quality and Preference. 116:105149. Clydesdale FM. 1991. “Color Perception and Food Quality.” Journal of Food Quality 4(1):61–74. Ertel W. 2018. Introduction to Artificial Intelligence. Cham (Switzerland): Springer. Frolov S, Hinz T, Raue F, Hees J, Dengel A. 2021. “Adversarial text-to-image synthesis: A review.” Neural Networks. 144:187–209. Janiesch C, Zschech P, Heinrich K. 2021. “Machine learning and deep learning.” Electron Markets. 31(3):685–95. Jelinčić DA. 2023. “Što utječe na doživljaj okusa?” In Znanost i umjetnost doživljaja hrane, 76–85. Zagreb: Jesenski i Turk. Kirova VD, Ku CS, Laracy JR, Marlowe TJ. 2023. “The Ethics of Artificial Intelligence in the Era of Generative AI.” JSCI 21(4):42–50. Misal T, Satyam K, Ronit B, Rohit A, Prof. Shreya B. 2024. “Detection of AI-Generated Images.” International Journal of Trend in Scientific Research and Development 8(5):805–10. Mugge R, Dahl DW, Schoormans JPL. 2018. “What You See, Is What You Get?” Guidelines for Influencing Consumers’ Perceptions of Consumer Durables through Product Appearance.” Journal of Product Innovation Management 35(3):309–29. NIJZ – Priporočila glede uživanja rdečega mesa in mesnih izdelkov. URL: https://nijz.si/zivljenjski-slog/prehrana/prehranske-smernice/priporocila-glede-uzivanja-rdecega-mesa-in-mesnih-izdelkov/ (last accessed on 14. 1. 2025) Ong SH, Ni SX, Vern HL. 2024. “Dimensions Affecting Consumer Acceptance towards Artificial Intelligence (AI) Service in the Food and Beverage Industry in Klang Valley.” Semarak International Journal of Machine Learning 1(1):20–30. Štampfl V, Ahtik J. 2024. “Quality of Colour Rendering in Photographic Scenes Illuminated by Light Sources with Light-Shaping Attachments.” Applied Sciences 14(5):1814. Šubic T. 2022. “Senzorične lastnosti klobas za kuhanje kot pomemben dejavnik pri odločitvi za nakup.” In Med vizijo in resničnostjo novih obzorij, edited by Tina Košir, Andrej Pogorelec, 309−322. Strahinj: Biotehniški center Naklo. Šubic T, Mavrin D, Leskovar Mesarič P. 2022. Meso in mesni izdelki. Podsmreka: Pipinova knjiga d.o.o. Morgan J. 2018. “The Influence of Color on Taste Perception”. Interesting Thing of the Day. URL: https://itotd.com/articles/3508/the-influence-of-color-on-taste-perception/ (last accessed on 18. 1. 2025) Wessel M, Adam M, Benlian A, Majchrzak A, Thies F. 2024. “Generative AI and its Transformative Value for Digital Platforms.” Journal of Management Information Systems. URL: https://www.jmis-web.org/cfps/JMIS_SI_CfP_Generative_AI.pdf (last accessed on 17. 1. 2025) Zelený J, Ulrichová A, Fišer V, Husák J, Svobodová D. 2024. “Gastronomic Consumers’ Attitudes Toward AI-Generated Food Images: Exploring Different Perceptions Based on Generational Segmentation.” In Marketing and Smart Technologies, edited by Reis JL, Zelený J, Gavurová B, Santos JPM dos, 105−119. Singapore: Springer Nature. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Lucija Brina Arvaj doc. dr. Jure Ahtik Chair of Information and Chair of Information and Graphic Arts Technology Graphic Arts Technology Faculty of Natural Sciences and Engineering Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana Aškerčeva 12 Aškerčeva 12 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia Tatjana Šubic, univ. dipl. inž. živ. teh. +386 40 699 246 Biotehniški center Naklo lucija.arvaj@gmail.com Strahinj 99 4202 Naklo, Slovenia 350 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION INCLUSIVITY AS A VALUE IN INFORMAL AND FORMAL PRIMARY SCHOOL EDUCATION - EXAMPLE OF VISUALIZING CHILDREN’S USER PATHWAYS Anja Sarjanović1, Delfina Fileva1, Melita Kožuh1, Brita Mandelj1, Alja Krklec1, and Helena Gabrijelčič Tomc1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The contribution presents student-centred didactic-research activities based on the Eutopia learning unit Urban Education. This research aligns with prior studies conducted in Belgium and France, addressing the central question: Does the future belong to cities? It explores inclusivity through a multidimensional approach, focusing on primary school pupils. At the Chair of Information and Graphic Arts Technology, we initiated the deve-lopment of a virtual educational city journey. This interactive environment allows teachers, parents, and guardians to follow pupils’ virtual paths and challenges in a „super-diverse“ urban context. Through web research we ana-lysed inclusivity in Slovenian primary schools. We defined categories of inclusivity for Slovenian primary schools and mapped daily pupil routes, identifying key learning opportunities within the city. The final prototype is a digital interactive game, placed as an interactive board along pupils’ routes. Featuring five challenges based on different diversity categories, the game fosters collaboration, empathy, and understanding among pupils by encouraging them to engage with diverse perspectives. Keywords: inclusivity, user-centred design, primary education, user paths, city, urban education. 1. INTRODUCTION Inclusivity ensures that all individuals, regardless of background, identity, or abilities, feel welcomed, valued, and respected. It goes beyond tolerance, actively embracing diversity in race, gender, age, disability, sexual orientation, and socioeconomic status (Thatcher, 2006). An inclusive society fosters equal opportunities, enabling people to contribute and thrive without fear of discrimination (Figure 1). In workplaces, schools, and communities, diversity drives innovation, creativity, and growth. True inclusivity requires intentional efforts ‒equitable policies, addressing biases, and ensuring accessibility (Gilbert, 2019). Small actions, like inclusive language or accessible spaces, make a difference. By embracing inclusivity, we create a society where everyone can reach their full potential (Microsoft, 2025). Figure 1: The quote of Vernā Myers (AppNexus, 2025) 351 29–30 May 2025, Ljubljana, Slovenia The research project work focused on the goals of Good Health and Well-being, Quality Education, Gender Equality, Reduced Inequalities, and Sustainable Cities and Communities. The research activities carried out within the Eutopia Urban Education (Eutopia, 2025) learning unit were designed to promote an interdisciplinary approach to addressing key social issues related to the inclusion of primary school children in Slovenia. The focus of the research project work was to design and prototype a virtual educational city journey. The aim was to integrate urban spaces with educational content for primary school pupils, to allow teachers, parents, and guardians to follow pupils’ paths through the city and better understand the challenges they face in a “super-diverse” educational context (United Nations Publications, 2022). 2. METHODOLOGIES The research was based on three key methodologies: a targeted analysis of the websites of Slovenian primary schools and the definition of inclusivity categories, user-centred design focused on primary school pupils as the main target group and the prototyping of the educational interactive pupil’s city path. The project steps were: • Analysis of inclusivity in primary schools: We reviewed existing inclusion practices in Slovenia (through the web publications) and analysed pupils’ routes from home to school, focusing on their chal-lenges and opportunities for informal learning. • Documenting diversity categories: We identified key diversity categories encountered in Slovenian urban primary schools and defined representative users. • Mapping home-to-school routes: We examined typical pupil routes for different groups and identified key “stopping points” in the urban environment where formal and informal learning content could be in-tegrated. • Developing a virtual environment prototype: We designed a virtual city journey, tailored to different diversity categories, embedding educational content to promote inclusivity. 3. RESULTS AND DISCUSSION Categorisation of the diversity that was defined from the analysis of the documents available on web of primary schools in Slovenia is presented in Figure 2. Figure 2: Categorisation of the diversity of the primary schools in Slovenia. 352 29–30 May 2025, Ljubljana, Slovenia 3.1 Summary of the Analysis of Primary School Websites on Inclusive Practices An analysis of primary school websites in Slovenia reveals differences in how inclusive practices are presented. Some schools highlight specific projects supporting pupils with special needs and immigrant children, while others provide limited information. Preventive workshops, conflict resolution programs, and language support for immi-grants are mentioned in some cases. However, not all schools detail their inclusion efforts online, and website quality varies. Oral sources confirm that certain schools offer Serbian language and culture classes for immigrant children, indicating that some inclusive practices may exist but are not always publicly documented. 3.2 Multiculturalism in Schools and Ethnic Discrimination In Slovenia, most immigrants come from Bosnia and Herzegovina, Kosovo, Serbia, Croatia, North Macedonia, and Ukraine. This diversity is reflected in primary schools, but there are no unified guidelines on how to address pupils of different ethnic backgrounds. Practices vary significantly—some schools ignore multicultural challenges, while others isolate immigrant pupils. Roma children face low teacher and peer expectations, often assumed to perform poorly, affecting their motivation. Many enter special education programs due to low grades or unfinished schooling. Social isolation further hinders their integration. Language barriers pose an additional challenge, as many pupils start school with little or no knowledge of Slove-nian, affecting comprehension and progress. Other ethnic minority pupils experience similar difficulties, including exclusion due to cultural differences. Schools lack systematic support for immigrant pupils’ native languages, leading to language loss and cultural identity erosion. Slovenian language instruction is available but often insuf-ficiently tailored to individual needs. 3.3 Inclusion of Children with Special Needs The inclusion of children with special needs in mainstream schools is a key aspect of educational policy, em-phasizing social support to reduce stress and enhance belonging and self-confidence. Historically, children with developmental disabilities were considered unfit for schooling, but this changed with the establishment of special-ized programs. From 1920 to 1960, segregation dominated, followed by integration between 1960 and 2000. True inclusive education only gained prominence after 2000. Slovenia intensified efforts in this field after the White Paper on Education (1995), leading to legislative changes, including the Placement of Children with Special Needs Act (2000). Since then, 28 specialized schools have been established, enrolling 11,077 pupils by 2017/2018. Modern education emphasizes inclusion as a core value, re-quiring adjustments in the learning environment, expert support, and funding to ensure equal opportunities for all children. Inclusive education adapts systems for all children, moving beyond segregation and integration to create accessible learning environments. 3.4 Target Groups and Personas According to the categorisation of the diversity the target groups were defined as follows: Children of Immigrant Parents – These children do not speak Slovenian as their native language, limiting their proficiency. However, they are socially active with diverse friendships. Their families typically have an average income, with both parents employed. They participate in extracurricular activities and hobbies, highlighting their engagement. Ensuring access to language and social resources is crucial for their successful integration. Children with ADHD/ADD or Autism – Often from low-income families, with one parent providing financial sup-port while the other cares for the child. Some come from high-income families where their condition is overlooked. They struggle with social inclusion, often feeling isolated and misunderstood. Limited access to school programs, therapy, and technology further hinders their development. 353 29–30 May 2025, Ljubljana, Slovenia Children with Physical Disabilities – Typically from extended families with authoritative parenting. They have a small but stable social network but face exclusion due to mobility limitations. Despite living in urban areas with better accessibility, they encounter challenges in full societal integration. Average Slovenian Child – From small families with authoritative upbringing and average income. Well-integrat-ed socially, they actively participate in various activities. They often live in rural areas and rely on public transport for school and extracurriculars, fostering strong peer support. Children with Behavioural and Emotional Disorders – Frequently from unstable family environments, with divorced parents. They have limited social networks and lack interest in school. Living in urban areas, they have access to resources but often fail to utilize them. Special support is essential to improve their socialization and emotional well-being. Personas were designed based on target groups. Fatima, age 15 – Recently moved from Bosnia, struggles with Slovenian, feeling excluded and frustrated. Finds school challenging due to fast-paced lessons and concentra-tion difficulties. Commutes 45 minutes by bus, waking up early. Uses technology for chatting and reading comics but feels lonely due to limited social integration. Blaž, age 13 – Struggles with attention issues affecting academ-ic performance. Has a strained relationship with his absent father. Enjoys outdoor activities and video games but feels different from peers. Walks or bikes to school in 15 minutes. Uses technology but has a basic phone due to financial limitations. Jakob, age 13 – Uses a wheelchair due to a spinal injury. Faces accessibility challenges in school despite supportive friends. His father drives him to school, causing stress due to inadequate facilities. Enjoys social media and video games, using technology extensively. Mojca, age 13 – Active in extracurriculars but struggles with peer relationships, impacting her confidence. Has a strong bond with her mother but feels misunderstood by her father. Walks 15 minutes to school, enjoys outdoor activities, and frequently uses Insta-gram and Messenger. Bor, age 15 – Lives with his emotionally distant mother, feeling isolated. Unmotivated in school, lacking friends, and associating with a negative peer group. Frequently late, disengaged, and struggling academically. Lives in the city center, heavily reliant on technology but lacking strong family connections. 3.5 Development of a Digital Prototype The prototype for the game “In Your Shoes” was designed to foster inclusivity and empathy among primary school pupils. The game allows players to experience different life situations faced by children with various needs, such as ADHD, physical disabilities, or immigrant backgrounds. This interactive experience helps children understand and empathize with the daily challenges of their peers. The prototype was developed in Figma for structuring the game and interactive challenges, while Canva was used for animations. The game features multiple interactive challenges accessible through interactive panels placed at key locations in the city, such as parks, libraries, and bus stops along pupils’ daily routes to school. These panels provide engaging tasks that encourage children to reflect on the challenges faced by marginalized groups. Players can engage with the challenges individually or in groups, even connecting panels from different locations for a shared experience. Access is secured through school credentials to ensure safety. In the prototype, the following challenges were included: • Word Association: Designed for children from immigrant backgrounds (e.g., Fatima), this challenge presents an interactive story where players make choices that shape the narrative, fostering empathy for immigrant experiences. At the end, the character becomes a digital companion who answers players’ questions about their life. • Find the Object: Simulating the struggles of children with ADHD/ADD or autism (e.g., Blaž), this chal- lenge requires players to find an object within a set time while distractions appear on the screen. This simulates the attention difficulties these children face. • Jump Challenge: Representing mobility-impaired children (e.g., Jakob), two players must complete a task while experiencing physical limitations (e.g., one with closed eyes, the other on one leg). This helps players understand the difficulties faced by children with physical disabilities. • Stand Against Bullying: Addressing the experiences of the average Slovenian child (e.g., Mojca), this challenge presents scenarios where players must decide whether to participate in or stop bullying, en-couraging awareness and proactive behavior. 354 29–30 May 2025, Ljubljana, Slovenia • My Garden: Highlighting the struggles of children with behavioral and emotional difficulties (e.g., Bor), players care for a virtual garden. When a helper (gardener) stops assisting, the game becomes signifi-cantly harder, illustrating the impact of losing support. Players can collaborate, promoting discussions about real-life support systems. Figure 3 present the interface of the prototype. The in-city placed interactive game serves multiple purposes. Each challenge educates children on the experiences of vulnerable groups while making learning accessible in 29–30 May 2025, Ljubljana, Slovenia public spaces. By situating the game outside traditional school settings—parks, libraries, and bus stops—it en-courages engagement in urban environments. The game supports both individual and group learning, enhancing a sense of belonging and cooperation in problem-solving. An interactive whiteboard in the park of city, inviting children to play. Designed illustrations on the interface pages. Prototype memory tasks. Prototype thinking tasks. Designed illustrations with the interaction elements on the interface pages. Figure 3: Figure 3: User inter User interface’s pages with interaction and content design. face’s pages with interaction and content design. 355 4. CONCLUSIONS This research underscores the vital role of inclusivity in education, ensuring all pupils, regardless of 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS This research underscores the vital role of inclusivity in education, ensuring all pupils, regardless of background or ability, feel valued and supported. By analyzing Slovenian primary school inclusivity practices and mapping children experiences, the study identifies barriers faced by immigrant children, pupils with disabilities, and those with behavioral or emotional challenges. The development of a virtual city learning journey offers an innovative approach to fostering inclusivity, integrating educational content into urban environments. The interactive proto-type, In Your Shoes, enhances empathy by allowing pupils to experience diverse challenges through gamification. Schools vary in their implementation of inclusive policies, with language barriers and social exclusion remaining significant obstacles. The study highlights the need for systematic support, tailored educational programs, and community engagement to create accessible learning environments. Through interdisciplinary collaboration and digital innovation, this research contributes to sustainable, inclusive education, ensuring equal opportunities for all pupils to thrive in a diverse society. Acknowledgement: We sincerely thank the Eutopia network for enabling the results of this research and enrich-ing the activities of the Urban Education learning unit through the student project. 5. REFERENCES Eutopia, Urban Education, URL: https://eutopia-university.eu/english-version/education/eutopia-learning-communites/urban-education (last accessed on 27.2. 2025). Gilbert, R. M. 2019. Inclusive Design for a Digital World: Designing with Accessibility in Mind (Design Thinking), Apress. Microsoft, Inclusive Microsoft Design. URL: https://download.microsoft.com/download/b/0/d/b0d4bf87-09ce-4417-8f28-d60703d672ed/ inclusive_toolkit_manual_final.pdf (last accessed on 27.2.2025) Thatcher, J., Urban, M., Lawson, B., Burks, M. R., Rutter, R. Kirkpatrick, A., Heilmann, C., Lawton, S., Regan, H. R. and Waddell, C., D. 2006. Web Accessibility: Web Standards and Regulatory Compliance, 1st ed. Edition, Apress. United Nations Publications. 2022. “Approaches to Measuring Social Exclusion.” Statistical standards and studies - Conference of European Statisticians, Ed. United Nations Publications. Vernā Myers, AppNexus, URL: https://www.youtube.com/watch?v=9gS2VPUkB3M&ab_channel=AppNexus ( last accessed 27.2. 2025). 356 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author: Helena Gabrijelčič Tomc Anja Sarjanović Delfina Fileva Graphic Arts and Design Graphic Arts and Design, Graphic Arts and Design Chair of Information and Chair of Information and Chair of Information and Department of Textiles, Department of Textiles, Department of Textiles, Graphic Arts Technology Graphic Arts Technology Graphic Arts Technology Faculty of Natural Sciences Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering and Engineering University of Ljubljana University of Ljubljana University of Ljubljana Aškerčeva 12 Aškerčeva 12 Aškerčeva 12 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia Melita Kožuh Alja Krklec Department of Textiles, Department of Textiles, + 386 1 200 3 291 Graphic Arts and Design Graphic Arts and Design helena.gabrijelcic@ntf.uni-lj.si Chair of Information and Chair of Information and Graphic Arts Technology Graphic Arts Technology Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering University of Ljubljana University of Ljubljana Aškerčeva 12 Aškerčeva 12 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia Brita Mandelj Department of Textiles, Graphic Arts and Design Chair of Information and Graphic Arts Technology Faculty of Natural Sciences and Engineering University of Ljubljana Aškerčeva 12 1000, Ljubljana, Slovenia 357 DESIGN AND TYPOGRAPHY 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION A BIBLIOMETRIC ANALYSIS OF TYPOGRAPHY RESEARCH Danica Dolničar1, Klementina Možina1 and Irena Sajovic1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Typography has long been an important part of communication, encompassing the design of typefaces, the study of print quality and legibility on paper or in digital media, but also including computer graphics, market-ing and psychology. In this paper, a bibliometric approach was used to examine the content structure and trends in typography research. Scopus and Web of Science databases were queried for typography-related terms. The results were subjected to pre-processing, followed by analysis using Bibliometrix/Biblioshiny (performance anal-ysis – document and citation counts) and VOSviewer software (science mapping – network visualisations). The results present the most cited documents, the most prolific and influential authors, the most prolific sources and the most frequent keywords. The keyword network reveals five main topic clusters, such as graphic design and printing, legibility/readability, reading comprehension/memory, perception/impact of design, character recognition and font generation. Trend topics are related to font generation by AI and font perception. Keywords: typography, bibliometric analysis, performance analysis, science mapping 1. INTRODUCTION Since the invention of movable type and the printing process by Johannes Gutenberg, typography has become an essential aspect of communication (Možina, 2003). Initially, the focus was mainly on the design of the typeface and the quality of the printed typeface (Tracy, 2003). Many decades later, the legibility of a typeface has become very important (Reynolds, 1998; Tinker, 1963). First on paper, then on screens with different resolutions (Dyson and Haselgrove, 2001; Reynolds, 1998; Tinker, 1963)there is an urgent need to increase our knowledge of factors influencing reading from screen. We investigate the effects of two reading speeds (normal and fast. Eye-tracking technology has been developed to measure reading time and legibility, allowing researchers to study the impact of typeface design on reading fluency and memorisation (Beier et al., 2017; Franken et al., 2015; Medved et al., 2023). There is also interest in how different typefaces influence marketing and business (Davis et al., 2019). Nowadays, studies are even investigating the role of typography in computer graphics (Jordan et al., 2017). The aim of this study was to examine the content structure and trends in the field of typography research to help scholars identify potential opportunities for new research from the perspective of topics, journals and references. 2. EXPERIMENTAL The present study follows the methodology for bibliometric analyses described by Donthu et al. (2021). We used two methodological approaches: (a) performance analysis to examine the annual scientific production and cita-tions and to identify the most prolific/cited authors, the most prolific sources, and the most cited documents, and (b) science mapping to identify and visualise the topic structure of the field and to identify trending topics based on the co-occurrence of keywords. The search strategy included typography-related keywords (typograph*, legibility/readability and text/font*/type-face/type, font/typeface design, typesetting and font/fonts, reading and font weight/color/size/type/characteristics, eye movement/track* and font/fonts/typeface*, typeface, but excluded typographical errors, typographi/typogra-phus beetles or linguistics) in the title and keyword search fields. Separate searches were carried out in the Sco-pus and Web of Science (WoS) databases, with results filtered by document type to include only journal articles, reviews, and conference papers. The search results were exported, combined (yielding 5579 documents) and im-ported into software programmes (Microsoft Excel, Bibliometrix/Biblioshiny and VOSviewer) to clean the original raw data, perform basic statistical analyses, create and visualise bibliometric networks and analyse the results. To improve the quality of the original raw dataset for further analyses, the pre-processing phase was essential. 359 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Duplicates were identified and removed from the combined set. The mean value of the total citations (TC) for WoS and Scopus was also calculated in this process. A thesaurus was created and used to merge key terms such as singular/plural, synonyms, different variants, different spellings, abbreviated and full terms. During the manual To improve the quality of the original raw dataset for further analyses, the pre-processing phase was review, the titles and abstracts of the documents were checked to exclude “false positives”. The final data set essential. Duplicates were identified and removed from the combined set. The mean value of the total comprised 3244 documents. citations (TC) for WoS and Scopus was also calculated in this process. A thesaurus was created and used to merge key terms such as singular/plural, synonyms, different variants, different spellings, abbreviated and full terms. During the manual review, the titles and abstracts of the documents were 3. checked to exclude “false positives”. The final data set comprised 3244 documents. RESULTS WITH DISCUSSION 3.1 Documents 3. RESULTS WITH DISCUSSION First, we examined the document types. Two thirds of the documents are journal articles, the rest are conference 3.1 Documents papers. Next, we looked at the number of documents and the number of total citations over time. Figure 1 shows First, we examined the document types. Two thirds of the documents are journal articles, the rest are that annual production has been steadily increasing since 1975, with a sharp increase in 2011. The means of conference papers. Next, we looked at the number of documents and the number of total citations over total citations shown in red take into account both the number of documents and the age of the documents. The time. Figure 1 shows that annual production has been steadily increasing since 1975, with a sharp documents from 2006 were cited most frequently. increase in 2011. The means of total citations shown in red take into account both the number of documents and the age of the documents. The d ocuments from 2006 were cited most frequently. 250 1,5 ] ber 200 1,2 ear ./y num 150 0,9 s [ /doc ent 100 C 0,6 oc 50 0,3 Mean T D um 0 0,0 90 95 00 05 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 00 05 10 15 20 25 18 18 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 Publication year Documents Mean TC/doc./year Figure 1: Production over time (number of documents), and mean of total citations (TC) Figure 1: Production over time (number of documents), and mean of total citations (TC) The documents were then ranked according to the total number of citations to determine the most influential documents. The ten most cited documents globally have at least 174 citations, with the paper The documents were then ranked according to the total number of citations to determine the most influential doc-by Rayner et al. (2006) topping the list with 285 citations. The average year of publication is also 2006. uments. The ten most cited documents globally have at least 174 citations, with the paper by Rayner et al. (2006) Thematically, the ten most cited papers deal with legibility/readability/reading, e.g. the influence of type half of the sentences were printed in a font that was easy to read (Times New Roman topping the list with 285 size and typeface (Henderson et al., 2004) , in the context of vision (Mansfield et al., 1996; Rayner et citations. The average year of publication is also 2006. Thematically, the ten most cited papers deal with legibility/ al., 2006) , learning and memory (Lorch, 1989; Ozcelik et al., 2010) , or the influence of typography in readability/reading, e.g. the influence of type size and typeface (Henderson et al., 2004), in the context of vision marketing (Hall and Hanna, 2004) , logos (Foroudi et al., 2014; Hagtvedt, 2011) or products (Henderson (Mansfield et al., 1996; Rayner et al., 2006)the authors measured the influence of font in reading with normal et al., 2004) . One document (Leeuwen, 2006) refers to the fundamentals of typography. The latest and low vision. METHODS: Reading acuity, maximum reading speed, and critical print size (the smallest print document (Azadi et al., 2018) deals with typeface style transfer using neural networks. that can be read with maximum speed, learning and memory (Lorch, 1989; Ozcelik et al., 2010)including: titles, headings, previews, overviews, summaries, typographical cues, recall sentences, number signals, importance 3.2 Authors indicators, and summary indicators. Most investigations have examined how the presence of signals in a text A total of 5775 authors contributed to our dataset. Ten authors published 14 or more documents each affects subsequent memory for the text. Virtually all types of signals produce better memory for information they (Table 1 ). Tinker is the only author with more than 30 publications, followed by Možina with 23. Six of cue in a text, whereas memory for unsignaled information often is unaffected. Less attention has been directed the top ten authors deal with legibility and three with automatic typeface recognition and/or generation. to signaling effects on other cognitive processes, such as attention, basic reading processes, and comprehen-The remaining author deals with design layout. Lian has the most citations overall and the most citations sion. It is argued that an understanding of how signals influence these processes will contribute to the application per document in the group. of signaling research to reading and writing instruction and to our general understanding of reading.”,”contain Aside from the most prolific authors, we looked at the most influential authors – those with the highest -er-title”:”Educational Psychology Review”,”ISSN”:”1573-336X”,”issue”:”3”,”journalAbbreviation”:”Educ Psychol number of citations regardless of the number of documents. In this list, Van Leeuwen is in first place Rev”,”language”:”en”,”page”:”209-234”,”source”:”Springer Link”,”title”:”Text-signaling devices and their effects on with 404 citations for just three documents, closely followed by the aforementioned Lian with 403 for 20 2 360 29–30 May 2025, Ljubljana, Slovenia reading and memory processes”,”volume”:”1”,”author”:[{“family”:”Lorch”,”given”:”Robert F.”}],”issued”:{“date-part s”:[[“1989”,9,1]]}}},{“id”:2604,”uris”:[“http://zotero.org/users/4575080/items/VCUXZFUT”],”uri”:[“http://zotero.org/ users/4575080/items/VCUXZFUT”],”itemData”:{“id”:2604,”type”:”article-journal”,”abstract”:”Previous studies have suggested that signaling enhances multimedia learning. However, there is not enough evidence showing why signaling leads to better performance. The goal of this study was to examine the effects of signaling on learning outcomes and to reveal the underlying reasons for this effect by using eye movement measures. The participants were 40 undergraduate students who were presented with either signaled or nonsignaled multimedia materials. Labels in the illustration were signaled by temporarily changing the color of the items. The results suggest that the signaled group outperformed the nonsignaled group on transfer and matching tests. Eye movement data shows that signaling guided attention to relevant information and improved the efficiency and effectiveness of finding necessary information.”,”container-title”:”Computers in Human Behavior”,”ISSN”:”0747-5632”,”issue”:”1”,”journal-Abbreviation”:”Computers in Human Behavior”,”language”:”en”,”note”:”p”,”page”:”110-117”,”source”:”ScienceDi-rect”,”title”:”Why does signaling enhance multimedia learning? Evidence from eye movements”,”title-short”:”Why does signaling enhance multimedia learning?”,”volume”:”26”,”author”:[{“family”:”Ozcelik”,”given”:”Erol”},{“fami-ly”:”Arslan-Ari”,”given”:”Ismahan”},{“family”:”Cagiltay”,”given”:”Kursat”}],”issued”:{“date-parts”:[[“2010”,1,1]]}}}],”s chema”:”https://github.com/citation-style-language/schema/raw/master/csl-citation.json”} , or the influence of ty-pography in marketing (Hall and Hanna, 2004), logos (Foroudi et al., 2014; Hagtvedt, 2011) or products (Hender-son et al., 2004). One document (Leeuwen, 2006) refers to the fundamentals of typography. The latest document (Azadi et al., 2018) deals with typeface style transfer using neural networks. 3.2 Authors A total of 5775 authors contributed to our dataset. Ten authors published 14 or more documents each (Table 1). Tinker is the only author with more than 30 publications, followed by Možina with 23. Six of the top ten authors deal with legibility and three with automatic typeface recognition and/or generation. The remaining author deals with design layout. Lian has the most citations overall and the most citations per document in the group. Aside from the most prolific authors, we looked at the most influential authors – those with the highest number of citations regardless of the number of documents. In this list, Van Leeuwen is in first place with 404 citations for just three documents, closely followed by the aforementioned Lian with 403 for 20 documents. The next three most influential authors are Legge, Baird and Velasco with more than 370 citations each. Of the most prolific authors, Tinker ranks 9th on this list of most cited authors. 361 29–30 May 2025, Ljubljana, Slovenia Table 1: Ten most productive authors with total citations (TC) and research topics. Rank TC/ Year Research topics / key-Author Doc. TC Doc. started words 1 Tinker M. Reading, legibility, type, 31 300.5 9.7 1927 A. speed, blinking 2 Možina Typography, legibility, text, 23 157.5 6.8 2007 K. type, print 3 Paterson Reading, legibility, type, 22 264.0 12.0 1928 D. G. speed 4 Hartley Typography, layout, in-21 211.5 10.1 1973 J. structional design 5 Uchida Font recognition, font gen-21 96.0 4.6 2013 eration, neural networks, S. style transfer Font recognition, font gen- 6 eration, neural networks, Lian Z. 20 403.0 20.2 2015 Chinese fonts, style trans- fer Fonts, legibility, reading, 7 Beier S. 18 154.0 8.6 2010 typography, letter recog- nition 8 Dobres Typography, legibility, 15 240.0 16.0 2014 typeface design, reading, J. size Font generation, neural 9 Choi J. 14 48.0 3.4 2017 networks, Chinese fonts, style transfer 10 Reimer Typography, legibility, 14 213.0 15.2 2012 typeface design, automo-B. tive, displays 362 29–30 May 2025, Ljubljana, Slovenia 3.3 Sources Among the ten most productive sources that published 19 or more documents, we find five journals and five conferences (Figure 2). Visible Language is the most productive journal with 49 documents. 48 documents were published in the proceedings of the ACM Conference on Human Factors in Computing Systems. The remaining titles deal with computer graphics and interactivity (Displays, conferences SIGGRAPH and HCII), psychology (Journal of Applied Psychology), design (Information Design Journal), communication (Visual Communication), ergonomics (Applied Ergonomics) and pattern recognition (conference ICDAR). Figure 2: Ten most productive sources; visualisation: Biblioshiny 3.4 Topics Combined authors- and Scopus-indexed keywords were first analysed for frequency (top 20 in Table 2). Typog-raphy was by far the most frequent keyword, followed by legibility and fonts. The keywords could be grouped by topic: 1) fonts, typefaces, typeface design, font design, typesetting; 2) design, graphic design, font design, type-face design; 3) recognition, OCR; 4) legibility, readability, reading, texts; 5) properties: font size, color, size; 8) study: perceptions, performance. 363 3.4 Topics Combined authors- and Scopus-indexed keywords were first analysed for frequency (top 20 in Table 2). Typography was by far the most frequent keyword, followed by legibility and fonts. The keywords could 29–30 May 2025, Ljubljana, Slovenia be grouped by topic: 1) fonts, typefaces, typeface design, font design, typesetting; 2) design, graphic design, font design, typeface design; 3) recognition, OCR; 4) legibility, readability, reading, texts; 5) properties: font size, color, size; 8) study: perceptions, performance. Table 2: Twenty most frequent keywords with frequencies of occurrence. Table 2: Twenty most frequent keywords with frequencies of occurrence. Rank Words Occurr. Rank Words Occurr. 1 typography 571 11 recognition 94 2 legibility 232 12 color 92 3 fonts 216 13 graphic design 92 4 design 162 14 typeface design 85 5 typefaces 141 15 perceptions 78 6 readability 131 16 eye movement 76 7 texts 130 17 OCR 71 8 font size 119 18 size 67 9 reading 110 19 font design 66 10 typesetting 107 20 performance 66 To visualise the thematic structure of the field, VOSviewer was used to create a co-occurrence network for the 234 most frequent keywords (frequency at least To visualise the thematic structure of the field, VOSviewer was used to create a co-occurrence network for the 234 ten , Figure 3). Typography was used as a stop word and therefore removed. Characteristics of the five keyword clusters, ordered by cluster size: most frequent keywords (frequency at least ten, Figure 3). Typography was used as a stop word and therefore removed. Characteristics of the five keyword clusters, ordered by cluster size: 2) graphics, visualization and kinetic typography; green (62, 2014) – legibility , readability, psychophysics of reading, font size, reading speed; 2) green (62, 2014) – legibility , readability, psychophysics of reading, font size, reading speed; 3) blue (36, 2017) – memory , reading fluency, dyslexia; 3) blue (36, 2017) – 4) yellow (32, 2016) – memory , reading fluency, dyslexia; perception , impact and emotions, associated with the use of 4) yellow (32, 2016) – 1) red (73 words, average year 2010) – classic graphic design topics, typesetting, printing, 1) red (73 words, average year 2010) – classic graphic design topics, typesetting, printing, computer computer graphics, visualization and kinetic typography; fonts/typefaces; perception, impact and emotions, associated with the use of fonts/typefaces; 5) 5) purple (31, 2016) – font purple (31, 2016) – font recognition recognition and generation using neural networks. and generation using neural networks. other topics. Some of words are close to the border between two clusters (e.g. ergonomics (between The yellow (design) cluster appears at the center of the visualization, indicating its connectedness to other topics. The yellow (design) cluster appears at the center of the visualization, indicating its connectedness to red and green clusters) or eye movements (between blue and green clusters). Some of words are close to the border between two clusters (e.g. ergonomics (between red and green clusters) To identify new and emerging topics, in addition to the average age of clusters, the overlay version of or eye movements (between blue and green clusters). the keyword network visualization in VOSviewer was chosen, where colour represents the average age To identify new and emerging topics, in addition to the average age of clusters, the overlay version of the keyword of the words (Figure 4). It can be seen that most of the oldest terms (coloured blue) can be found in the network visualization in VOSviewer was chosen, where colour represents the average age of the words (Figure first cluster (e.g. typesetting, computer graphics and printing). Examples of common middle-aged terms 4). It can be seen that most of the oldest terms (coloured blue) can be found in the first cluster (e.g. typesetting, (in green) are legibility, readability/reading, fonts, design and recognition. The newest terms are coloured computer graphics and printing). Examples of common middle-aged terms (in green) are legibility, readability/ in yellow. These mainly include words from cluster 5 that relate to the use of neural networks (e.g. font reading, fonts, design and recognition. The newest terms are coloured in yellow. These mainly include words from generation, style transfer, deep learning), from cluster 3 (e.g. fluency, beliefs and dyslexia) and 4 (e.g. cluster 5 that relate to the use of neural networks (e.g. font generation, style transfer, deep learning), from cluster perceptions and impact). In cluster 2, the new term is helmet mounted displays. These are 3 (e.g. fluency, beliefs and dyslexia) and 4 (e.g. perceptions and impact). In cluster 2, the new term is helmet predominantly specific/niche terms found on the outer edge of network visualization. mounted displays. These are predominantly specific/niche terms found on the outer edge of network visualization. The five most cited papers in the last four years (between 28 and 56 citations) deal with the text readability in social media (Gkikas et al., 2022) , typographic enhancement in language learning The five most cited papers in the last four years (between 28 and 56 citations) deal with the text readability in so-(Majuddin et al., 2021) , automatic typeface generation (Xie et al., 2021) , typeface perception in relation cial media (Gkikas et al., 2022), typographic enhancement in language learning (Majuddin et al., 2021), automatic to food (Motoki and Velasco, 2021) and icon legibility on displays (Shen et al., 2021) . typeface generation (Xie et al., 2021), typeface perception in relation to food (Motoki and Velasco, 2021)round shapes are associated with sweet taste, while angular shapes are associated with sour and bitter tastes. Previous studies have focused on one-to-one taste-shape associations, where either geometrical shapes or shapes on a product’s packaging have been presented in isolation and evaluated separately. However, in real-life product dis-4 plays, products are typically surrounded by other products. We examined whether shape contexts can influence the taste expectations associated with target products across five experiments (n = 1087 and icon legibility on displays (Shen et al., 2021). 364 29–30 May 2025, Ljubljana, Slovenia Figure 3: Main research topics by keyword network; visualisation: VOSviewer Figure 4: Keyword network by publication years; visualisation: VOSviewer 365 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS Our study provides an overview of the development of the research field of typography, drawing on two method-ological approaches: performance analysis and science mapping. The oldest documents indexed in the WoS and Scopus bibliographic databases on typography research date from 1892, but the number of documents began to increase after 1975, with a sharp increase in 2011. The documents with the most citations deal with a range of topics, including the influence of typefaces on reading and perception, characteristics of letterforms, the influence of text colour and text signalling. Miles A. Tinker, who published his work before 1970, and Klementina Možina, after 2007, are the most prolific authors, while Theo Jacob van Leeuwen and Zhouhui Lian are the most frequently cited. Most papers were published in the journal Visible language and at the ACM Conference on human factors and computing. Apart from typography, the most common keywords are fonts, legibility and design. The topics identified through the scientific mapping deal with graphic design and printing, legibility/readability, reading com-prehension/memory, perception/impact of design, character recognition and font generation. Type size is the most studied property. Recent topics include font generation using neural networks, user experience in XR, dyslexia research related to reading, and the impact/perception of design. There are some limitations of the present study that should be mentioned. We could use co-word analysis in com-bination with co-citation analysis or bibliographic coupling to enrich the understanding and interpretation of the thematic clusters, to gain additional insights into the dynamics of the field and to predict future developments. In addition, the set of keywords, databases and database search fields could be extended to include more docu-ments in the analyses. 5. 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Behaviour & Information Technology 23 (3): 183–95. Henderson, P.W., Giese, J.L., and Cote, J.A. 2004. ‘Impression Management Using Typeface Design’. Journal of Marketing 68 (4): 60–72. Jordan, T.R., Al Shamsi, A.S., Yekani, H.A., Al Jassmi, M., Al Dosari, N., Hermena, E.W., and Sheen, M. 2017. ‘What’s in a Typeface? Evidence of the Existence of Print Personalities in Arabic’. Frontiers in Psychology 8:1–8. Leeuwen, T. van. 2006. ‘Towards a Semiotics of Typography’. Information Design Journal 14 (2): 139–55. Lorch, R.F. 1989. ‘Text-Signaling Devices and Their Effects on Reading and Memory Processes’. Educational Psychology Review 1 (3): 209–34. Majuddin, E., Siyanova-Chanturia, A., and Boers, F. 2021. ‘Incidental Acquisition of Multiword Expressions through Audiovisual Materials: The Role of Repetition and Typographic Enhancement’. Studies in Second Language Acquisition 43 (5): 985–1008. Mansfield, J.S., Legge, G.E., and Bane, M.C. 1996. ‘Psychophysics of Reading. 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ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Danica Dolničar Klementina Možina Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering University of Ljubljana University of Ljubljana Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška 5 1000, Ljubljana, Slovenia Snežniška 5 SI-1000, Ljubljana, Slovenia +386 1 2003 242 klementina.mozina@ntf.uni-lj.si danica.dolnicar@ntf.uni-lj.si Irena Sajovic University of Ljubljana +386 1 2003 276 Faculty of Natural Sciences and Engineering Department of Textiles, Graphic Arts and Design Snežniška 5 1000, Ljubljana, Slovenia +386 1 2003 254 irena.sajovic@ntf.uni-lj.si 367 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION TYPOGRAPHY STUDY PRACTICES (LETTERS AND SHAPES: COLLECTION OF TYPOGRAPHIC EXERCISES) Domen Fras1 1University of Ljubljana, Academy of Fine Arts and Design, Slovenia Abstract: Typography offers endless and ever-changing possibilities for graphic design. The success of a design-er’s career in setting and pushing the intellectual and physical boundaries of typography depends largely on the skills acquired in the earliest stages of a visual communication design degree. This paper is the result of a decade’s development of practical study processes in typography and type design collected in an online publication titled Letters and Shapes. It includes a wide range of content based on typo-graphic traditions, 20th-century modernist principles, simple artistic experimentation and current technological possibilities. Assignments are always carried out in a “design, consult and evaluate” cycle. They combine analogue techniques with the use of digital tools. This encourages students to develop their design skills in later years when they are faced with more complex tasks. Teachers, however, are challenged to ask themselves contemporary questions that we can explore in the typographic medium. Keywords: Typography, graphic design, study, assignments, exercises. 1. INTRODUCTION The field of typography presents a vast array of possibilities for graphic design, offering a wealth of opportuni-ties for exploration and innovation. The success of a designer‘s career in pushing the intellectual and physical boundaries of typography is contingent, to a considerable extent, on the competencies acquired during the initial stages of visual communication design studies. The challenge for students and teachers alike is to apply today the knowledge of typography accumulated over the last 500 years. 1.1 Literature and sources in the field The publication of literature in the field of graphic design and typography in the English language is an ongoing process, with both professional and non-professional works being published. These books primarily address current production practices from the perspective of the author‘s or editor‘s position and the policies of publishing houses. Monographs offer insights into the work and output of the authors in question. Textbooks such as Inside Paragraphs (Highsmith, 2012), How to Design Typefaces (Henestrosa et. al. 2017), Detail in Typography (Hochuli, 2008), Stop Stealing Sheep & Find Out How Type Works (Spiekermann, Ginger, 2003) are authored by educators and provide students with a solid foundation in the fundamental principles of the discipline, while concurrently directing them towards an appreciation of the distinctive particulars that are impera-tive for professional accomplishment in the domain of typography. However, there is a paucity of translated literature on typography in the Slovenian language. Among the few tran-slated works is Emil Ruder‘s pioneering work Typography (Ruder, 1977). A prolific author of original Slovenian professional literature is Prof. Dr. Klementina Možina, who wrote a comprehensive textbook, Tipografska Kunšt (Možina, 2023), in 2023. The majority of literature on this subject focuses on achieving professional standards, with comparatively little attention devoted to the pedagogy of typography and student artworks. A notable exception is Thinking with Type 368 29–30 May 2025, Ljubljana, Slovenia (Lupton, 2010), a textbook that offers practical applications and links theory to student projects. This book has served as a valuable source for the exercises included in this text, which have been further refined over time. 1.2 The primary objective The primary objective of this publication (Collection of exercises and assignments Letters and Shapes: Collection of typographic exercises) is to offer a comprehensive array of content, drawing upon the traditions of calligraphy and letterpress, 20th-century modernist principles, simple artistic experimentation and current technological po-ssibilities 2. EXPERIMENTAL (MATERIALS AND METHODS) 2.1 Conception of the collection The Letters and Shapes collection of exercises is the result of a decade of development in the study of typography and type design in regular and elective courses. The archiving of student work was conducted in either analogue or digital format. A comprehensive array of literature and online sources has been consulted for the design of the exercises in this collection, with the author having attended international typography conferences and sharing teaching experiences with colleagues. The texts and delivery incorporate the order and discipline that I typically aim to instil in the classroom environ-ment. The importance of typographic discipline for the autonomous and consistent completion of exercises is emphasised in lectures, which are supported by theoretical foundations, historical contexts, and references from design practice. 2.2 Chapters in the collection The exercises and assignments have been organised into seven chapters, which cover a broad range of topics. These include basic typographic vocabulary and grammar, typographic applications, the relationship between function and form, control of complex layouts, type as image, and the fundamentals of typeface design with an emphasis on analogue approaches and digital implementations. The final chapter provides a synopsis of the practical study undertaken by small groups of students, which fosters communication during the execution and presentation of the results of the task. 2.3 Structure of the instructions Exercise and task instructions consist of three elements. Firstly, a guiding thought that contextualises the problem and the resulting task. Secondly, a guide for implementation. And thirdly, a tip. The learning outcomes at the end of the texts serve as an orientation for evaluating the results of the study with multiple solutions. 2.4 Criteria for the selection of student works The selection of student work for publication is predicated on two fundamental criteria: the innovation of the so-lution and the quality of the execution. Concurrently, the pursuit of diversity in the results of the study has been undertaken to emphasise the extensive possibilities for students to confront the challenges of design. 2.5 Publication design The design concept is pragmatic, and as this is the inaugural version of an open-access electronic publication, the format chosen is 16:9 for spread and 8:9 for a single page. The selected images of student works are diverse in terms of format, colour, scale, technique and media, while the written task instructions are uniform in structure and predominantly balanced in word count. 369 29–30 May 2025, Ljubljana, Slovenia The text of the exercises is consistently positioned on the leftmost edge of the spread and aligned to the left, while the internal hierarchical division enables readers to engage with the task instructions to varying degrees of depth. The images are distributed freely over the subsequent one or two spreads, with each spread forming a new picto-rial composition. The layout was realised using Adobe InDesign, and the typeface family used was Degular Mono. The export file is an interactive PDF of medium JPG quality. 3. RESULTS WITH DISCUSSION The initial version of the publication is exclusively available in digital PDF format, accessible via the UL Publishing House website and the UL ALUO website. The publication’s design incorporates an Adobe InDesign master file, which facilitates the subsequent preparation of files for printing. 3.1 Chapters The publication comprises seven chapters, encompassing 63 exercises with accompanying example solutions. The total content encompasses 626 units of visual material across 210 pages, with the chapters meticulously structured to align with the sequence of the exercises by year. Each chapter functions as an independent entity, yet is interconnected with the others: Letter, word, line and paragraph; Function and form; Position control, Letter in drawing; Glyph, letter and font; Typeface design, School typography workshops 3.2 Chapter contents Letter, word, line and paragraph (Fig.1) In the initial year of the programme, the study of typography is founded upon an exposition of the fundamental typographic vocabulary and grammar. Thematic units address the letter, word, line and paragraph in the visual relationships of the printed and unprinted surface. Guided exercises initiate the development of a palette of typo-graphic resources, which the individual implements in a comprehensive design pursuit as the course progresses. Figure 1: Spread from the chapter Letter, word, line and paragraph 370 29–30 May 2025, Ljubljana, Slovenia Function and form (Fig. 2) In the subsequent year, the study of typography is oriented towards applied typography. The course teaches stu-dents to understand the criteria for selecting typefaces, plan and design complex problems, respond critically to typographic essays and develop a visual language through the interpretation of a quotation. Students are taught to think of typography as a vehicle for a verbal message and an element of visual identity. Figure 2: Spread from the chapter Function and form Position control (Fig. 3) The habitat of typography is flat. Typesetting is done horizontally and vertically while reading the Latin alphabet is done only from left to right and from top to bottom. The ability to manipulate the coordinate system in which we operate is a pivotal skill for typographers. Figure 3: Spread from the chapter Position control 371 29–30 May 2025, Ljubljana, Slovenia Letter in drawing (Fig. 4) Despite the expanding array of typefaces available, it is often challenging to select or define the optimal typeface for a given task. In such instances, it is advisable to employ a custom approach. Rather than relying on typefaces that inadequately replicate handwriting, it is preferable to utilise one’s handwriting. Figure 4: Spread from the chapter Letter in drawing Glyph, letter and font (Fig. 5) A plethora of approaches to type design have been shown to broaden typographic horizons and strengthen drawing skills. Although each assignment highlights one of the approaches, together they form a setting for un-derstanding system design by integrating different design methods. Each of these methods shapes the designer and their authorial expression in its own way. Figure 5: Spread from the chapter Glyph, letter and font 372 29–30 May 2025, Ljubljana, Slovenia Typeface design (Fig. 6) The impetus for embarking upon the pursuit of typeface design can vary, with the predominant motivation being the student’s inherent fascination with typography. The undertaking of tasks may stem from a personal inclination, a research endeavour, or the necessity for a specific project if the typeface is developed concomitantly with the project to which it is affiliated. In our approach, we commence the delineation of characters from a conceptual and functional foundation, cognizant of the inherent interconnectedness among letterforms. The efficacy of a typeface is contingent upon its practical application; consequently, type designers must adopt dual roles: that of the user of the typeface (the graphic designer) and that of the user of the message (the reader). Figure 6: Spread from the chapter Typeface design 373 29–30 May 2025, Ljubljana, Slovenia School typography workshops (Fig. 7) School workshops constitute a complementary element to lectures, serving as an introduction to independent study. Students engage in collaborative work in small groups to discuss topics and identify solutions to problems, undertaking this task manually without the use of any intermediary tools. The primary medium employed is paper, with collage techniques serving as the principal method of representation. The act of transferring the cut-out piec-es onto the paper facilitates a connection among group members, and the outcomes of their collaborative efforts are made immediately apparent and can be objectively evaluated. After each workshop, a presentation of all the solutions is conducted, followed by a collective discussion among all participants. Figure 7: Spread from the chapter School typography workshops 4. CONCLUSIONS The publication provides a synopsis of the pedagogical praxis employed in the Typography courses within the Visual Communication Design programme. The exercises and assignments are meticulously structured according to a well-established sequence, facilitating the acquisition of competencies about layering. The exercises and assignments are systematically executed within a recurrent cycle encompassing ‘design, consultation and evalu-ation’. The duration of these exercises and assignments varies depending on the level of study and the complexity of the assignments. They can be completed within a few class periods, spanning a single lecture, or they may extend over a whole semester. A common feature of all assignments is the integration of analogue techniques and digital tools, fostering the development of design skills, even in the later years of study as the assignments become more challenging and complex. The Letters and Shapes collection can be regarded as a cross-section of my pedagogical engagement over the past decade, offering a framework for a critical assessment of the quality, relevance and, ultimately, the actuality of the study of typography in the given circumstances. Although the publication is a complete whole, it is not a finished product; rather, it is a starting point for refinement, iteration and constant adaptation. I plan changes in approaches, methods and delivery of content. It is beneficial to deviate from established rou-tines, to omit or substitute exercises, to restructure them, or even to redesign them entirely. This approach is instrumental in maintaining a questioning mindset and utilising typographic methodologies to identify potential solutions. 374 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Books Highsmith, Cyrus, Inside paragraphs: typographic fundamentals. Boston: Font Bureau, 2012. Henestrosa, Christóbal, Laura Meseguer, in José Scaglione, How to create typefaces: from sketch to screen. Madrid: Tipo e, 2017. Hochuli, Jost, Detail in typography: letters, letterspacing, words, wordspacing, lines, linespacing, columns. New ed. London: Hyphen Press, 2008. Lupton, Ellen, Thinking with type: a critical guide for designers, writers, editors, & students. 2nd rev. and Expanded ed. New York: Princeton Architectural Press, 2010. Možina, Klementina, Tipografska kunšt: upodobitev informacij. 1. izd. Ljubljana: Naravoslovnotehniška fakulteta, 2023. Ruder, Emil, Tipografija: priročnik tipografskega oblikovanja = Tipografija = Typographie. Ljubljana: Partizanska knjiga; Znanstveni tisk, 1977. Spiekermann, Erik, in E. M. Ginger, Stop stealing sheep & find out how type works. 2nd ed. Berkeley, Calif.: Adobe Press, 2003. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Domen Fras Department of Visual Communication Design Academy of Fine Arts and Design University of Ljubljana Erjavčeva cesta 23, 1000 Ljubljana, Slovenia +386 40 63 72 74 Domen.Fras@aluo.uni-lj.si https://www.aluo.uni-lj.si/en/sodelavke-sodelavci/fras-domen/ 375 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION ADAPTING BOOK COVER DESIGN BASED ON ITS TARGET GROUP Nuša Gabrijel1, Valentina Smej Novak2 and Klementina Možina1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2 Založba Vida, Slovenia Abstract: Understanding the target group is essential when wanting to design a visually effective product, espe-cially in the case of books. The appearance of a book reveals the story and message of the book, and leaves a lasting impression on the reader. Therefore, it is important to understand the psychology of colour and recognise the message expressed by the chosen typefaces and their shapes. The aim of this study was to identify the adjustments needed in the cover design of three different novels depending on their target group. Using the es-tablished guidelines, we designed a fantasy adventure novel for children, a contemporary novel for young adults and a contemporary romance novel for women. We were inspired by the current trends in the design of fiction books on the market. The design process leading up to the final product, including the colours and typefaces, was slightly different for each novel. Keywords: target group, graphic design trends, fiction, book cover, book design. 1. INTRODUCTION Understanding the target group is essential when wanting to design a visually effective product, especially in the case of books. The appearance of a book reveals the story and message of the book, and leaves a lasting impres-sion on the reader. Each element used in the book design can influence the reader in its own way. Therefore, it is important to understand the psychology of colour and recognise the message expressed by the chosen typefaces and their shapes. In order for the book to reach its target group, it is not only important to understand the psychol-ogy and follow established design guidelines, but we must also consider current design trends. By researching the market and paying attention to current trends, we can design a book that reveals its genre (Storyboard That, 2024), target gender and age of its readers by its appearance alone. In this study, we designed three different novels to visually appeal to a corresponding target group. When ana-lysing the current state, we found that the plot of the book is not only revealed by the genre (Storyboard That, 2024), but also by the cover design, chosen colours (Anderson Feisner, 2014), typefaces (Možina, 2023), graphic elements (Guide to Book Layout, 2024; Hendel, 1998; O’Connell, 2024) etc. We investigated the associations we have with certain colours and the importance of understanding the psychology of colour in conveying the message of the book (Anderson Feisner, 2014). We analysed the characteristics of typefaces and defined their components. We realised that the book cover plays a decisive role in the marketing of the book (Davies, 2024). It represents the reader’s first contact with the book and can amuse, captivate, annoy or even repel them. The book cover expresses the tone and message of the text, which can indicate the book’s genre and target group. While the cover piques the reader’s interest, the interior design must maintain that interest (McCullough, 2024; The Psychology Behind Good Book Cover Design, 2024). We researched the market and trends in the design of young adult books and found that their covers often feature an illustration of a character or scene from the story with eye-catching illustrations appropriate to the genre of the book (How to Design a Young Adult Book Cover, 2024; Roberts, 2024; Young Adult Book Covers, 2024). We also investigated the trends in the design of books for adult women and concluded that these books are perceived as inferior due to their typical appearance (Bender, 2024; Darstaru, 2024; Roberts, 2024). The aim of this study was to identify the adjustments needed in the cover design of three different novels depend-ing on their target group. 376 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL We designed the book’s cover for three different novels. We designed a fantasy adventure novel for young adults, a contemporary novel for young adults and a contemporary romance novel for women. We were inspired by the current trends in the design of fiction books on the market. For the Slovenian fantasy adventure novel Varuhi življenja for children (from nine to 14 years old), we created several designs (Figure 1). The contemporary novel Moj brat lovi dinozavre for young adults (from 11 to 18 years old) is a translation from Italian. First, we made two different designs (Figure 2), where we had to take some inspi-ration from the original design. Therefore, we designed four more versions of the book’s cover (Figure 3). Based on the feedback from the original Italian publisher and their request to change the colour palette, we kept the orig-inal colour hierarchy idea, only altering it to shades of green (Figure 3, right). The contemporary romance novel Sedem sester for women was translated from English. For the design, we initially took the inspiration from the original design (Figure 4, left); however, we soon changed the style (Figure 5). All of the pink or yellow elements were planned to be printed using foil stamping with gold foil. The original publisher requested to add an armillary sphere to the cover; hence, we decided to replace it with the element of Rio at the bottom (Figure 5). Figure 1: First two drafts of cover for Varuhi življenja Figure 2: First two drafts of cover for Moj brat lovi dinozavre Figure 3: Third, fifth, sixth and seventh draft of cover for Moj brat lovi dinozavre 377 29–30 May 2025, Ljubljana, Slovenia Figure 4: Original cover (left) and first draft (right) of cover for Sedem sester Figure 5: Second, third, sixth and eight draft of cover for Sedem sester 3. RESULTS WITH DISCUSSION 3.1 Book cover for novel Varuhi življenja The book conveys its message through a fantasy story. Since dragons play an important role in it, we decided to use them as the main inspiration for the cover (Figure 6). Any colour in the original colour palette seemed too prosaic for a majestic and magical creature like a dragon. The colour purple is inter alia associated with spirituality, magic and fantasy. Therefore, we decided to build a new colour palette around purple. We chose a combination of purple, dark green, dark blue and pink instead of different darker or lighter shades of purple for the cover not to look too monotonous. For the title Varuhi življenja, we chose the handwritten typeface P22 Stanyan in bold. We chose this typeface since we could imagine that it was the handwriting of one of the children’s characters in the book. It does not look too serious and elegant; however, it conveys playfulness and youthfulness. We set the title in a size of 73 pt. Above the title, we added the authors’ names in the sans-serif typeface Termina in a size of 11 pt. We set both the title and the authors’ names in white, creating a contrast between the text and the background. Figure 6: Final cover jacket for Varuhi življenja 378 29–30 May 2025, Ljubljana, Slovenia 3.2 Book cover for novel Moj brat lovi dinozavre We created eight different designs for the book cover, the last of which was used for the final product (Figure 7). After designing the light green cover, we decided to combine the darkness of the blue version with the new green, resulting in a dark green cover. The title on the front and the synopsis of the book on the back were kept in soft yellow, while the short summary and the author’s name on the front and the publisher’s logo and website link on the back were kept in soft green. We coloured the silhouette of the boy in darker orange. The outlines of the plants were coloured in dark shades of green, while the outlines of the dinosaurs and the boy were coloured in the same yellow as the title. The same colour was also used for the stars and the elements on the spine. For the title, we chose the decorative typeface BD Supper in 49.7 pt, which has the characteristics of a sans-serif graphic typeface. Below the title, we added the author’s name in the same typeface in 23.4 pt. For the text on the back cover, we chose the transitional typeface Baskerville URW in 11.6 pt. Figure 7: Final cover jacket for Moj brat lovi dinozavre 3.3 Book cover for novel Sedem sester The tenth version of the book cover design was selected for the final product (Figure 8). For the women’s novel, we chose a design that was not part of the typical design trends for women’s novels and thus challenged gende-risation. For the design not to appear too complex, we chose a simple and plain colour palette. We focused on cooler colours for the background to create a better contrast between the background and the gold foil. We opted for blue, taking into account research on the preferred colours of our target audience, i.e. middle-aged women. Due to the risk of designing an atypical cover for a women’s novel, we were reliant on the typefaces chosen to appeal to the target audience; thus, it was important that they had a more feminine feel. For the title on the front cover, we chose the decorative typeface Rosalia in 40 pt, with its mix of soft and sharp strokes to match the overall design of the cover. The geometric sans-serif font Century Gothic in 26 pt. was used for the author’s name. To achieve balance, the title was set in uppercase while the author’s name was written in lowercase. For the short summary at the top of the back cover, the bold version of Century Gothic was used in 10 pt type size. For the longer summary of the book, we chose the transitional typeface Baskerville Display in 10.5 pt. 379 29–30 May 2025, Ljubljana, Slovenia Figure 8: Final cover jacket for Sedem sester In the final analysis of the design and production of the novels, we analysed the success and quality of the de-sign. We identified errors that occurred during the process. These errors were noted to avoid their repetition in the future. 4. CONCLUSION The study identifies the adjustments needed in the cover design of three different novels depending on their target group. We were inspired by the current trends in the design of fiction books on the market. The design process leading up to the final product, including the colours and typefaces, was slightly different for each novel. For the Slovenian fantasy adventure novel for children, we created several designs. The third one was selected for the fi-nal product. The contemporary novel for young adults is a translation from Italian. We had to take some inspiration from the original design. We created eight different designs for the book cover, the last one being used for the final product. The contemporary romance novel for women was translated from English. For the design, we initially took inspiration from the original design; however, we soon changed the style. The tenth version was selected for the final product. For the women’s novel, we chose a design that was not part of the typical design trends for women’s novels and thus challenged genderisation. In the final analysis of the design and production of the novels, we analysed the success and quality of the de-sign. We identified errors that occurred during the process. These errors were noted to avoid their repetition in the future. 380 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Anderson Feisner, E. and Reed, R. 2014. Color studies. New York: Fairchild Books, pp. 184–188. Bender, J. YA Cover Art: Changes and Social Impact in the Last Twenty-Five Years. URL: https://scholarsarchive.byu.edu/cgi/viewcontent. cgi?article=1065&context=english_symposium (last accessed on 27. 2. 2024). Darstaru, A. Design stereotypes: What Defines Feminine Design or Masculine Design? URL: https://www.creatopy.com/blog/masculine-design-feminine-design/ (last accessed on 27. 2. 2024). Davies, P. The Psychology of Aesthetics and Style: How We are Attracted to These Notions. URL: https://play3r.net/news/the-psychology-of-aesthetics-and -style-how-we-are-attracted-to-these-notions/ (last accessed on 27. 2. 2024). Guide to Book Layout: What Makes a Book More Readable? URL: https://blog.reedsy.com/book-layout/ (last accessed on 27. 2. 2024). Hendel, R. 1998. On Book design. London: Yale University Press, pp. 4, 35. How to Design a Young Adult Book Cover: A Step-by-Step Guide. URL: https://www.publishingpush.com/blogs/how-to-design-a-young-adult-book-cover-a -step-by-step-guide (last accessed on 19. 3. 2024). McCullough, M. A. Young Adult Book Cover Design and Its Impact on Reader Interest. URL: https://firescholars.seu.edu/cgi/viewcontent. cgi?article=1148&context=honors (last accessed on 27. 2. 2024). Možina, K. 2023. Tipografska kunšt. Ljubljana: Naravoslovnotehniška fakulteta, pp. 48–65, 71–76, 83–86, 207–211. O’Connell, K. C. Young Adult Book Cover. URL: https://dl.uncw.edu/Etd/2010-1/oconnellk/kathleenoconnell.pdf (last accessed on 23. 2. 2024). Roberts, R. Seeking Attention: What Covers Attract Readers. URL: https://editingresearch.byu.edu/2022/06/09/seeking-attention-what-covers-attract-readers/ (last accessed on 27. 2. 2024). Storyboard That. URL: https://www.storyboardthat.com/sl/articles/e/literarno-zvrsti (last accessed on 8. 3. 2024). The Psychology Behind Good Book Cover Design. URL: https://writerunboxed.com/2017/09/17/the-psychology-behind-good-book-cover-design/ (last accessed on 27. 2. 2024). Young Adult Book Covers. URL: https://coverkitchen.com/young -adult#:~:text=The%20trends%20in%20YA%20book,digital%20thumbnails%20and%20 physical%20books (last accessed on 19. 3. 2024). ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-authors: Klementina Možina Nuša Gabrijel Faculty of Natural Sciences and Engineering and Engineering University of Ljubljana University of Ljubljana Snežniška ulica 5 Snežniška ulica 5 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia Graphic Arts and Design Graphic Arts and Design Faculty of Natural Sciences Department of Textiles, Department of Textiles, +386 1 200 32 00 nusa.gabrijel20@gmail.com klementina.mozina@ntf.uni-lj.si Valentina Smej Novak Založba Vida +386 1 200 32 42 Poljanska cesta 6 1000 Ljubljana, Slovenia +386 41 371 777 valentina@zalozbavida.si 381 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION HOW COMPREHENSIBILITY OF PACKAGING SYMBOLS DEPENDS ON THE LEVEL OF ENVIRONMENTAL AWARENESS OF CONSUMERS Anđela Brekalo, Ivana Čalić, Luka Ljuban, Marina Šuša, Antonela Zvonković, 1 Dorotea Kovačević and Maja Brozović 1 1 University of Zagreb, Faculty of Graphic Arts, Croatia Abstract: The solution to packaging recycling is found by using symbols for proper waste disposal and increasing consumer environmental awareness. Previous research has shown the influence of demographic characteristics on the understanding of symbols on packaging. The aim of this paper is to examine the influence of age and level of education on the understanding of symbols and consumer environmental awareness. The research was conducted using an online survey in which 126 respondents participated. Respondents were asked to explain the meaning of 9 standardized symbols: International Symbol for Recyclable Packaging, Green Dot, Don‘t Pollute / Let‘s Save Nature!, Eu Eco Label, WWF World Wildlife Fund, Numbering System and Abbreviations for Packaging Labeling, Separate Waste Collection, FSC (Forest Stewardship Council), Compostable. The results showed the influence of age and environmental awareness on the understanding of environmental symbols, while the level of education did not affect the understanding of symbols. Keywords: packaging, recycling symbols, understandability of symbols, environmental awareness 1. INTRODUCTION Environmental awareness refers to the recognition of the interconnection between human actions, sustainability, and responsibility, based on the understanding that humans and ecosystems coexist in a shared environment. Eco-labeling of products influences consumer awareness by signaling that the product’s manufacturing process meets ecological standards, i.e., that it has the least possible environmental impact. However, an excessive num-ber of eco-labels can lead to information overload, which may reduce their effectiveness in guiding purchasing decisions. This confusion may arise from the ambiguity of terms used in eco-labels, which may not align with con-sumer knowledge (Mitchell, 2005). A practical example is that consumers often do not understand environmental protection information on labels such as “CFC-free,” “eco,” and “green,” especially the differences between them. A study by Moon et al. (2016) shows that too much information on eco-labels reduces understanding. The abil-ity to understand ecological symbols on packaging depends on numerous factors. Age has been identified as a significant determinant of attitudes toward the environment, as well as the studies conducted on this topic. The nature of these relationships is influenced by social, societal, and economic factors (Ogunbode, 2012). Previous research suggests that younger individuals are more aware of environmental issues (Arcury, 1990; Inglehart, 1995; Whitehead, 2006). Recent studies confirm an increase in environmental awareness among younger con-sumers, evident in their purchasing choices and pro-environmental behaviors (Wierzbiński, 2021), especially among millennials, who are actively involved in promoting sustainability (Carrión-Bósquez, 2024). Research by Abdul-Wahab (2010) showed that people with higher levels of education are more knowledgeable about ecology and environmental conservation, while Ogunbode (2012) found no differences among respondents with different educational backgrounds. Pam Scholder’s research (1994) examined the recognition of symbols on packag-ing. The results indicated less objective and perceived knowledge among older individuals and those with only a high school education. Labeling on packaging and products can be ambiguous, which leads to difficulties in sorting waste into the appropriate recycling and collection systems (Jóźwik-Pruska, 2022). Eco-labels should be designed to be easily understood, visually appealing, and highly visible to facilitate product evaluation (Donato, 2022; Magnier, 2015). Symbols on packaging encourage pro-environmental behavior, making their understanding crucial. Previous studies have shown that individuals who have encountered ecological symbols are more likely to recognize and understand these symbols on packaging (Ma, 2018). Therefore, the aim of this paper is to examine 382 29–30 May 2025, Ljubljana, Slovenia the impact of age and educational level on the understanding of symbols on packaging and overall environmental awareness among product users. Four hypotheses are proposed: H1: Younger individuals are more environmentally aware than older individuals – this aims to explore environmen-tal awareness across three age groups of respondents. H2: Younger individuals understand symbols on packaging better than older individuals – the assumption is that younger people are more familiar with ecological symbols due to ongoing education, internet usage, and greater openness to new ideas compared to older individuals. For older individuals, symbol recognition may be linked to experience, which younger people may lack. H3: Individuals with higher levels of education understand ecological symbols on packaging better – higher edu-cation levels lead to more knowledge gained through years of schooling, both theoretical and practical, providing more experience than individuals with lower levels of education (Abdul-Wahab, 2010). H4: Understanding ecological symbols increases with greater environmental awareness – individuals who recycle waste must recognize the ecological symbols on packaging. However, the question remains whether individuals who do not prioritize the environmental aspect do so out of negligence or because they are unfamiliar with the ecological symbols. 2. EXPERIMENTAL To assess comprehensibility, nine standardized symbols commonly found on product packaging were used: the International Symbol for Recyclable Packaging, the Green Dot, “Do Not Litter / Protect Nature!”, the EU Ecola-bel, the WWF (World Wildlife Fund) logo, the Plastic Resin Identification Codes, the Separate Waste Collection symbol, FSC (Forest Stewardship Council), and the Compostable symbol (Figure 1). Comprehensibility was eval-uated using a symbol recognition method—respondents were asked to describe what they believed the symbol represented, and if they did not recognize the symbol, they were instructed to respond with “I do not recognize it.” Environmental awareness was measured based on statements that respondents rated using a 5-point Likert scale. The survey was conducted via an online questionnaire, with a total of 126 participants (Table 1) Figure 1: Symbols on product packaging Table 1: Respondent characteristics N Gender Male 52 Female 74 Age 18-34 (young) 96 35-64 (middle-age) 14 65+ (older) 16 Education Secondary education 43 Bachelor’s or equivalent 39 Master’s or equivalent 36 Doctorate or equivalent 8 383 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS The results show greater environmental awareness among younger people compared to middle-aged and older people (Table 2). Table 2. Results of respondents’ self-assessment of environmental awareness Age N Mean Std. Deviation Std. Error Mean Environmental aware- 18-34 96 4,1979 ,65886 ,06724 ness 35-64 14 3,8216 1,0759 ,28756 65+ 16 3,8750 ,71880 ,17970 The results of understanding symbols depending on the age of the respondents showed that understanding of ecological symbols decreases with increasing age (Table 3). Table 3. Results of understanding symbols depending on the age of the respondents 95% Confidence Inter- val for Mean N Mean Std. Devia-Std. Error L o w e r U p p e r Min. Max. tion Bound Bound 18-34 96 2,8333 1,67122 ,17057 2,4947 3,1720 ,00 7,00 35-64 14 2,2143 1,96815 ,52601 1,0779 3,3507 ,00 6,00 65+ 16 ,8750 1,58640 ,39660 ,0297 1,7203 ,00 6,00 Total 126 2,5159 1,80548 ,16084 2,1975 2,8342 ,00 7,00 To check statistical significance within groups, Post Hoc multiple comparison tests Tukey HSD and Games-How-ell test were used (Table 4). The tests differed in comparing the mean age with the others, but both tests showed that the results between the younger and older population were statistically significant (P < 0.01). 384 29–30 May 2025, Ljubljana, Slovenia Table 4. Results of Post Hoc Multiple Comparison Tests 95% Confidence Inter- val for Mean (I) Age (J) Age Mean Difference Std. Error Sig. Lower Upper (I-J) Bound Bound Tukey 18-34 35-64 ,61905 ,48496 ,411 -,5315 1,7695 HSD 65+ 1,95833* ,45774 <,001 ,8724 3,0443 35-64 18-34 -.61905 ,45496 ,411 -1,7695 ,5315 65+ 1,33929 ,62036 ,082 -,1325 2,8110 65+ 18-34 -1,95833* ,45774 <,001 -3,0443 -,8724 35-64 -1,33929 ,62036 ,082 -2,8110 ,1325 18-34 35-64 ,61905 ,55297 ,516 -,8091 2,0472 65+ 1,95833* ,43172 <,001 ,8699 3,0467 35-64 18-34 -.61905 ,55297 ,516 -2,0472 ,8091 65+ 1,33929 ,65877 ,125 -,3017 2,9802 65+ 18-34 -1,95833* ,43172 <,001 -3,0467 -,8699 35-64 -1,33929 ,65877 ,125 -2,9802 ,3017 *The mean difference is significant at the level 0.05 level. Furthermore, the influence of education level on the understanding of environmental symbols on packaging was examined. The results (Table 5) showed that understanding of symbols increases with higher education level up to master’s/doctorate. In these results, it is crucial to consider the sample size and its possible impact on the accuracy of the results. The small sample size of respondents with a master’s/doctorate degree is not considered relevant and was not taken into consideration. Table 5. Results of understanding symbols depending on the level of education of the respondents 95% Confidence Interval for Mean N Mean Std. Devi-Std. Er-L o w e r U p p e r Min. Max. ation ror Bound Bound Secundary education 44 2,1591 1,72456 ,25999 1,6348 2,6834 ,00 7,00 Bachelor’s or equivalent 38 2,6053 1,79398 ,29102 2,0156 3,1949 ,00 7,00 Master’s or equivalent 36 3,1389 1,85400 ,30900 2,5116 3,7662 ,00 7,00 Doctorate or equivalent 8 1,2500 1,03510 ,36596 .3846 2,1154 ,00 3,00 Total 126 2,5159 1,80548 ,16084 2,1975 2,8342 ,00 7,00 Finally, the understanding of symbols was examined based on the respondents’ ecological awareness. It was assumed that respondents with a higher level of ecological awareness would have a better understanding of eco-logical symbols. The ANOVA test showed greater understanding of symbols with increasing ecological awareness (Table 6). 385 29–30 May 2025, Ljubljana, Slovenia Table 6. Results of understanding symbols depending on the level of ecological awareness 95% Confidence Interval for Mean N Mean Std. Devi-Std. Er-L o w e r U p p e r Min. Max. ation ror Bound Bound Medium level of environmental 28 1,3571 1,49603 ,28272 ,7770 1,9372 ,00 7,00 awareness High level of environmental aware- 63 2,5714 1,67249 ,21071 2,1502 2,9926 ,00 7,00 ness Highest level of environmental 35 3,3429 1,81404 ,30663 2,7197 3,9660 1,00 7,00 awareness Total 126 2,5159 1,80548 ,16084 2,1975 2,8342 ,00 7,00 Post Hoc Tukey HSD and Games – Howell tests showed that the data were statistically significant between all groups except the group with high and highest environmental awareness, which also showed an increase, but not as statistically significant (Table 7). Table 7. Results of Post Hoc Multiple Comparison Tests 95% Confidence Interval for Mean (I) Environmental (J) Envi- Mean Dif- Std. Error Sig. Lower Upper Bound awareness ronmental ference Bound awareness (I-J) Tukey (1) Medium-high 2 -1,21429* ,38080 ,005 -2,1177 -,3109 HSD level of environ- 3 -1,98571* ,42509 <,001 -2,9942 -,9772 mental awareness (2) High level of w 1 1,21429* ,38080 ,005 ,3109 2,1177 awareness 3 -,77143 ,35345 ,078 -1,6100 ,0671 (3) Highest level 1 1,98571* ,42509 <,001 ,9772 2,9942 of environmental 2 ,77143 ,35345 ,078 -,0671 1,6100 awareness Games- (1) Medium-high 2 -1,21429* ,35261 ,003 -2,0626 -,3660 Howell level of environ- 3 -1,98571* ,41708 <,001 -2,9877 -,9838 mental awareness (2) High level of 1 1,21429* ,35261 ,003 ,3660 2,0626 environmental 3 -,77143 ,37205 ,103 -1,6636 ,1207 awareness (3) Highest level 1 1,98571* ,41708 <,001 ,9838 2,9877 of environmental 2 ,77143 ,37205 ,103 -1,207 1,6636 awareness *The mean difference is significant at the level 0.05 level. 386 29–30 May 2025, Ljubljana, Slovenia 4. RESULTS DISCUSSION Previous research indicates that younger individuals exhibit a higher level of environmental awareness com-pared to the older population (Abdul-Wahab, 2010; Ogunbode, 2012), which confirms the first hypothesis (H1). Considering age as a factor in understanding environmental symbols, the results show that younger individuals have a better understanding of environmental symbols than the older population, thereby confirming the sec-ond hypothesis (H2). The level of environmental awareness and familiarity with environmental symbols is often linked to the level of education and knowledge of ecology and sustainability. Individuals with a higher degree of environmental awareness are more conscious of the importance of sustainability and environmental protection, making them more sensitive to information about environmental symbols when purchasing products. This study has demonstrated a connection between the level of education and the comprehension of symbols on packag-ing, which supports the third hypothesis (H3). A consumer’s level of environmental awareness can significantly influence their understanding of packaging symbols. Those with a high level of environmental awareness are fa-miliar with symbols used to indicate the ecological characteristics of products and can recognize symbols related to recycling, energy efficiency, environmental certification, or sustainability. On the other hand, individuals with lower environmental awareness are less familiar with these symbols and their meanings, reducing their ability to recognize them. This may stem from a lack of environmental education or a lower interest in sustainability and environmental protection, thereby confirming the fourth hypothesis (H4). It is important to note that the comprehensibility of packaging symbols depends not only on the observer’s level of environmental awareness but also on the clarity and universality of the symbols themselves. If the symbols are simple, intuitive, and visually well-presented, they can be understood by a broad range of individuals, regard-less of their level of environmental awareness. People who have previously interacted with certain symbols or have engaged with environmental topics, such as recycling or waste reduction, are more likely to recognize and understand packaging symbols (Ma, 2018). The findings reveal an unexpected result: a significant proportion of participants—nearly 74%—claimed to recognize a specific symbol and provided responses accordingly. However, further analysis showed that these responses were inaccurate. This result highlights the complexities of human cognition, emphasizing the potential for perception to be misleading. The discrepancy between confidence and correct answers suggests a possible overestimation of one’s own knowledge. We assume that participants often avoid leaving answers blank, instead choosing responses that seem logical in order to appear knowledgeable. Furthermore, when comparing our results with previous research by Pam Scholder (1994), interesting similarities emerge. Scholder’s study found that participants, on average, correctly identified 4 out of 9 symbols presented, whereas our findings indicate an average of 3.3 out of 9 symbols. Although there is a slight difference in average results, the overall pattern remains consistent. Both studies demonstrate that participants faced challenges in accurately recognizing and recalling symbols. 5. CONCLUSION Based on the obtained results, there has been a noticeable increase in environmental awareness in recent years, driven by technological advancements and greater access to information. The Internet has become a key platform for spreading knowledge about climate change and sustainability, particularly among younger generations who use it daily as a source of information (Pew Research Center, 2021). According to Boykoff (2011) and Levy and Spicer (2013), digital media and social networks shape public discourse and the understanding of environmental issues. Examples such as Greta Thunberg and the #FridaysForFuture movement highlight the power of online campaigns in raising awareness and mobilizing the public. However, to bring about meaningful ecological change, this awareness must be further strengthened through consistent education and learning—beyond what the Inter-net alone can offer. The research showed that the majority of respondents understand the recycling symbol, which can be attributed to its standardized design and widespread global use, making it one of the most commonly taught symbols. We propose the introduction of specialized educational programs within the curriculum that would place greater emphasis on other environmental symbols and aspects of ecology, helping to familiarize younger generations with environmental topics. 387 29–30 May 2025, Ljubljana, Slovenia This study revealed that respondents, regardless of their characteristics, recognized fewer than 40% of the sym-bols presented, raising important questions. Why do people struggle to understand packaging symbols? To ad-dress this, we propose guidelines for further research on this topic. We believe the issue could be examined by designing different types of symbols (either low-structured or high-structured) to determine whether the current symbols provide too much or too little information, impacting their comprehensibility. Additionally, we suggest that future research should involve a larger sample of participants to enable a more in-depth analysis of the relation-ship between these variables. 6. REFERENCES Abdul-Wahab, S. A. and Abdo, J. 2010. “The Effects of Demographic Factors on the Environmental Awareness of Omani Citizens.” Human and Ecological Risk Assessment 16 (2): 380-401. Arcury, T.A. 1990. “Environmental Attitude and Environmental Knowledge.” Human Organization 49 (4): 300-304. Carrión-Bósquez, N., Veas-González, I., Naranjo-Armijo, F., Llamo-Burga, M., Ortiz-Regalado, O., Ruiz-García, W., Guerra-Regalado, W. and Vidal-Silva, C. 2024. “Advertising and Eco-Labels as Influencers of Eco-Consumer Attitudes and Awareness - Case Study of Ecuador.” Foods 13 (2): 228. Donato, C. and Adigüzel, F. 2022. “Visual complexity of eco-labels and product evaluations in online setting: Is simple always better?” Journal of Retailing and Consumer Services 67: 102961 Inglehart, R. 1995. “Public Support for Environmental Protection: Objective Problems and Subjective Values in 43 Societies.” Political Science & Politics 28 (1): 57-72 Jóźwik-Pruska, J., Bobowicz, P., Hernández Vázquez, C.I. and Szalczyńska, M. 2022. “Consumer Awareness of the Eco-Labeling of Packaging.” Fibres and Textiles in Eastern Europe 30(5): 39-46. Levy, David L. and Andre Spicer (2013). “Contested Imaginaries and the Cultural Political Economy of Climate Change.” Organization, 20(5): 659–678 Ma, G., Rau, P-L.P. and Guo, Z. 2018. “The Effects of Environmental Awareness and Consumption Value on Green Makeup Product Purchase Intentions.“ Psychology 9(7): 1898-1916. Magnier, L. and Crié, D. 2015. “Communicating packaging eco-friendliness: An exploration of consumers’ perceptions of eco-designed packaging.” International Journal of Retail & Distribution Management 43(4/5): 350-366. Mitchell, V.W., Walsh, G. and Yamin, M. 2005. “Towards a Conceptual Model of Consumer Confusion.” Advances in Consumer research, 32: 143-150. Moon, S.J., Costello, J.P. and Koo, D.M. 2016. “The impact of consumer confusion from eco-labels on negative WOM, distrust, and dissatisfaction.” International Journal of Advertising 36 (2): 246-271 Ogunbode, C. and Arnold, K. 2012. “A Study of Environmental Awareness and Attitudes in Ibadan, Nigeria” Human and Ecological Risk Assessment 18: 669-684. Pam Scholder, E. 1994. “Do we know what we need to know? Objective and subjective knowledge effects on pro-ecological behaviors.” Journal of Business Research 30(1): 43-52. Alec T., Brian K. and Cary F. (2021). “Climate, energy and environmental policy.” Pew Research Center Veltri, G. A., & Atanasova, D. (2017). “Climate change on Twitter: Content, media ecology and information sharing behaviour.” Public Understanding of Science, 26(6), 721–737. Whitehead, J.C. 2006. “Environmental Interest Group Behaviour and Self ‐Selection Bias in Contingent Valuation Mail Surveys.” Growth and Change 22 (1): 10-20. Wierzbiński, B., Surmacz, T., Kuźniar, W. and Witek, L. 2021. “The Role of the Ecological Awareness and the Influence on Food Preferences in Shaping Pro-Ecological Behaviour of Young Consumers.” Agriculture 11 (4): 345. 388 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Maja Brozović Anđela Brekalo Department of Graphic e-mail: andela.brekalo.01@gmail.com Faculty of Graphic Arts Ivana Čalić Design and Imaging University of Zagreb e-mail: ivana.calic01@gmail.com Getaldićeva 2 Luka Ljuban 10000 Zagreb e-mail: lukaljuban0@gmail.com +385 1 2371 080/213 Marina Šuša maja.brozovic@grf.unizg.hr e-mail: marina.susa1608@gmail.com Antonela Zvonković e-mail: antonela.zvonkovic@gmail.com Dorotea Kovačević Department of Graphic Design and Imaging Faculty of Graphic Arts University of Zagreb Getaldićeva 2 10000 Zagreb +385 1 2371 080/226 dorotea.kovacevic@grf.unizg.hr 389 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION COMPARISON OF A SELF-CREATED VISUAL CORPORATE IDENTITY WITH ONE GENERATED BY ARTIFICIAL INTELLIGENCE Sara Mužar1, Tanja Medved1 and Helena Gabrijelčič Tomc1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: This study examines the role of generative artificial intelligence (AI) in designing corporate visual iden-tities (CVI) and compares it with traditional design methods. With the growing use of AI in creative industries, the research explores whether AI can replace human creativity or if the human factor remains essential. The study investigates the impact of AI on quality, time efficiency, and adaptability. In the experimental part, two CVIs were created for a company specializing in the rental of soft-serve ice cream machines: one using traditional methods and the other with AI tools. Three AI tools were tested, and feedback was collected via surveys and A/B testing. Results show that AI significantly improves automation and time efficiency but requires human input for custom-ization and creativity. While AI delivers quality results, human involvement remains critical for achieving optimal outcomes, highlighting the need for integrated approaches. Keywords: generative artificial intelligence, corporate visual identity, graphic design, artificial inteligence tools, soft-serve ice cream 1. INTRODUCTION In the last decade, artificial intelligence (AI) has become a key factor in creative industries, including graphic de-sign. This research paper examines the role of artificial intelligence (AI) in designing a corporate visual identity (CVI) and compares it with traditional design methods. A CVI is a crucial communication element for any company, as it forms the foundation of its identity and marketing communication. Every interaction with a brand represents communication or information that is part of the brand’s identity, enhancing recognition and increasing differentiation (1). CVI consists of several fundamental elements, such as colors, typography, slogans, logos, or symbols, which together create a comprehensive representation of the brand (2). All elements must be designed to ensure effective application across various media, both traditional and digital, and to adapt to different business sectors and markets in which the company operates (3). AI is one of the newest fields of science and engineering, which began serious development shortly after World War II, though the term only became established in 1956. The first work that is now widely recognized as AI was conducted by Warren McCulloch and Walter Pitts in 1943 (4, 5). Throughout history, AI has evolved through various phases: neural networks (1950–1970), machine learning (1980–2010), deep learning (2011–2020), and generative AI (present) (5). AI is a technology that enables computers and machines to simulate human intelligence and problem-solving capabilities through algorithms. In graphic design, generative AI, utilizing advanced algorithms and machine learn-ing, facilitates the automation of tasks such as logo generation, color scheme selection, and the design of various CVI applications. It serves as a crucial tool for rapidly creating diverse design solutions (6, 7). With the rapid advancement of AI, a fundamental question arises: can this technology replace human creativity in design, or will the human factor remain essential for achieving optimal results? 390 29–30 May 2025, Ljubljana, Slovenia The study examines the impact of generative AI on the quality, time efficiency, and adaptability of CVI. It focuses on three hypotheses: (H1) CVI created without AI will be more tailored to the client’s preferences, (H2) AI will shorten the design timeline, and (H3) AI will enable a technically refined final product. The research is based on a case study of a specific company for which two CVIs were created—one using a traditional approach and the other utilizing AI. The significance of the study arises from the increasing use of AI in creative industries. Traditionally, graphic design tasks have been performed exclusively by human designers, whose creativity and adaptability were es-sential. Advances in AI now allow for the automation of many of these processes, raising questions about the efficiency and suitability of AI compared to human work. This research provides insight into how AI can transform design processes and whether it can achieve results equal to or even superior to those of human designers. In this study, we conducted a comparative analysis of two approaches to CVI design: the traditional method and the AI-assisted approach. In collaboration with a company specializing in the rental of soft-serve ice cream ma-chines, we developed two CVIs—one using traditional methods and the other utilizing AI tools. The experimental phase included time measurement of each design stage, enabling a comparison of the time efficiency of both approaches. The AI tools used in the study included generative algorithms for logo creation, color scheme selection, and other graphic elements. Feedback from target users, along with a comparison of time-related data, provided a compre-hensive analysis of the efficiency and adaptability of both methods. 2. EXPERIMENTAL The experimental phase of the study was divided into two parts: 1. CVI design without AI assistance: This approach involved the manual creation of a logo, selection of color schemes, and design of various CVI applications. 2. CVI design using generative AI: The tools used included Looka (8), Design AI (9), and Design.com (10), which enable the automation of certain design processes. In this case as well, the goal was to create a logo, select a color scheme, and design various CVI applications suitable for different media. The entire design process, from concept to realization, was subject to time measurement. As part of the CVI, we designed a logo that incorporated both graphic and typographic elements. The client requested that the logo for the company Točen sladoled also include the logo of its parent company, DSM. In addition to the primary and secondary logos, we designed the following materials: a business card, letterhead, flyer, social media post, graphic for social media stories, profile and cover images for social media, and a web advertisement. Before initiating the design process, we conducted a market analysis, examining the CVIs of four Slovenian com-panies operating in a similar industry as our client. Our focus was primarily on the following aspects: logo design, typography and color selection, consistency of CVI elements, and alignment between print and digital materials. We also conducted research on generative AI tools designed for graphic design. After a thorough analysis of twelve different tools, we selected the three most suitable ones—Looka (8), Design AI (9), and Design.com (10)— to first attempt logo creation. The most effective tool proved to be Design.com, which was subsequently used to develop the remaining CVI elements, including stationery and digital graphics. The experimental phase also included testing the target audience’s satisfaction with both design methods. To achieve this, we conducted a survey among the target audience using an A/B testing method. The goal of this survey was to assess the efficiency and quality of graphic outputs generated by AI compared to those created by human designers. 391 29–30 May 2025, Ljubljana, Slovenia We aimed to determine how users perceive AI-generated graphic elements and how these compare to those designed by human professionals. Additionally, we explored which design aspects (e.g., professionalism, clarity, creativity, attractiveness) are most important to users across different types of graphic materials and whether AI-generated designs can meet these expectations. 3. RESULTS WITH DISCUSSION As part of our research, we created two versions of the CVI for the company Točen sladoled: one was designed using conventional methods without AI assistance, while the other was developed using AI tools. The fundamental element of any CVI is the logo. In Figure 1, the logo created without AI is presented, whereas Figure 2 displays the logo generated with AI. The AI tools did not provide the option to create a secondary version of the logo, nor did they allow for integration with the logo of the parent company, DSM. Figure 1: The logo we designed traditionally, without AI, in both primary and secondary versions (positive and negative). 392 29–30 May 2025, Ljubljana, Slovenia Figure 2: The logo we designed using AI in its primary and only version. In addition to the logo, we designed several corporate printed materials, including a business card, letterhead, and flyer. For digital media, we created various graphics for social media branding, such as a profile picture, cover image, story, post, and a web advertisement. All of these can be found in Appendices A (1–6) and B (1–6). We also measured the duration of both design processes. A detailed record of the time measurements for individ-ual design phases of both design processes is presented in Appendices C and D. The AI-assisted design process required significantly less time (1 h 45 min) compared to the traditional design process (19 h 55 min). The outcomes of our work, as well as those generated by AI, were evaluated through an online survey involving 31 respondents, of whom 13 were male and 18 female. Their ages ranged from 25 to 50 years. Participants received no payment for their participation. Sixty-seven percent of respondents held higher education degrees (associate, bachelor’s, or university level). Twenty-four participants reported previous experience with artificial intelligence (AI) before completing the survey. Respondents were asked to rate their agreement with the statement, “Do you believe that artificial intelligence can lead to highly refined products in graphic design?” on a scale from 1 to 5 (1 indicating strong disagreement, 5 indicating strong agreement). Sixteen respondents selected rating 4, twelve selected rating 3, and only three respondents selected rating 5. Thus, respondents generally agreed that AI can create refined products, although their agreement was somewhat cautious. In the second part of the survey, respondents chose between graphics created by AI and those designed manual-ly. They were also able to provide reasons for their choices. When choosing a logo, 68% preferred manually de-signed logos, citing more attractive colors, font style, and overall visual appeal. For business cards, 55% preferred AI-generated designs, while 52% found manually designed letterheads more attractive. Regarding social media materials (profile picture, posts, stories, and cover images), most respondents (20 out of 31) preferred manually designed materials, citing more creative and engaging designs better suited for social media communication, as well as the use of product-specific photographs (soft-serve ice cream). When selecting a web advertisement and flyer, 74% preferred manually designed materials due to their greater attractiveness and effectiveness, clearer element layout highlighting the ice cream, and more direct messaging. In the final question, which asked respondents if they could identify AI-created materials, 55% correctly identified the AI-generated designs.The results are presented in Figure 3. 393 29–30 May 2025, Ljubljana, Slovenia Figure 3: Respondents’ recognition of AI-generated work Unexpected challenges primarily arose with AI tools. Currently, most of them do not support diacritical marks, which presented a significant issue for us. Some tools lack clear definitions of certain concepts, for instance, soft-serve ice cream (with some tools displaying a popsicle instead). The biggest challenge was that the tools are still only available in English and are not optimally adapted for use in other languages. Additionally, some tools are quite complex to use, requiring precise input or selection of appropriate terms to achieve the desired results. In the broader context, our findings reflect the need for further exploration of the collaboration between AI and human creativity. While AI provides an exceptional tool for accelerating and optimizing certain processes, human designers remain essential for creating and tailoring outcomes to meet the unique requirements of each client. This opens new possibilities for the development of hybrid working methods, where AI and human creativity col-laborate, potentially enhancing the efficiency and quality of final products in creative industries. 4. CONCLUSIONS Based on our findings, we can confirm Hypothesis 1: CVI created without AI will be more tailored to the client’s preferences. It has been demonstrated that, compared to AI, human design remains more flexible and better able to adapt to client requirements while also delivering higher-quality solutions. This confirms that human creativity and adaptability remain key components of successful client-oriented graphic design. We can also confirm Hypothesis 2: AI will shorten the design timeline. Based on our measurements and final results, the entire design process was significantly shorter when using AI compared to traditional, non-AI design methods. Hypothesis 3: AI will enable a technically refined final product, can be partially confirmed. Our survey results indicated that respondents preferred products designed by humans. While AI facilitated technically adequate solutions, human intervention was required to achieve a final product that was not only technically refined but also functionally and aesthetically tailored to its specific context of use. The study confirms that AI provides an effective alternative to traditional graphic design methods, particularly in reducing time constraints. However, human creativity remains crucial for developing customized and unique solu-tions. The optimal approach appears to be a combination of traditional methods and AI, leveraging the strengths of both. Future research should focus on integrating AI with traditional methods to maximize their efficiency and adaptabil-ity. Additionally, it is recommended to explore the long-term impact of AI on creative industries and its contribution to innovation. 394 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Wiedemann, J. 2009. Brand identity now!. Hong Kong: Taschen. Wiedemann, J. 2009. Logo design. Hong Kong: Taschen. Wheeler, A. 2013. Designing brand identity: An essential guide for the whole branding team. New Jersey: John Wiley & Sons. Russell, J. S., Norving, P. 2010. Artificial intelligence a modern approach. New Jersey: Pearson Education. Artificial intelligence, what it is and why it matters. URL: https://www.sas.com/en_us/insights/analytics/what-is-artificial-intelligence.html/ (last accessed on 15. 3. 2024). Generativna umetna inteligenca spreminja ustvarjalni potek dela. URL: https://www.adobe.com/si/products/ firefly/discover/how-ai-changes-creative-work.html/ (last accessed on 20. 3. 2024). Hampus, Dehman. Graphic design, Already Intelligent?: Current possibilities of generative AI applications in graphic design.URL: https://www.diva-portal.org/smash/get/diva2%3A1797022/FULLTEXT02.pdf/ (last accessed on 7. 2. 2025). Looka. URL: https://looka.com/ (last accessed on 7. 2. 2025). Design.ai. URL: https://designs.ai/ (last accessed on 7. 2. 2025). Design.com. URL: https://www.design.com/ (last accessed on 7. 2. 2025) 6. APPENDIECES Appendix A1: Business card designed without AI (two sided) 395 29–30 May 2025, Ljubljana, Slovenia Appendix A2: Letterhead designed without AI 396 29–30 May 2025, Ljubljana, Slovenia Appendix A3: Flyer designed without AI 397 29–30 May 2025, Ljubljana, Slovenia Appendix A4: Graphics for social media designed without AI – post (five versions) Appendix A5: Graphics for social media designed without AI – storie (four versions) 398 29–30 May 2025, Ljubljana, Slovenia Appendix A6: Graphics for digital media designed without AI: digital advertisement Appendix B1: Business card designed with AI (one sided) 399 29–30 May 2025, Ljubljana, Slovenia Appendix B2: Letterhead designed with AI 400 29–30 May 2025, Ljubljana, Slovenia Appendix B3: Flyer designed with AI Appendix B4: Graphics for social media designed with AI – post (three versions) 401 29–30 May 2025, Ljubljana, Slovenia Appendix B5: Graphics for social media designed with AI – storie (three versions) Appendix B6: Graphics for digital media designed with AI – digital advertisement 402 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Appendix C: Appendix C: Time measurement of CVI creation without AI Time measurement of CVI creation without AI Corporate visual identity elements Time measured in minutes Meeting with the client 60 Market and trend research 48 Creation of a mind map 62 Color palette (selection, adjustments) 60 Typography 70 Logo (inspiration search) 42 Logo (sketch development) 40 Logo (creation of initial versions) 180 598 Logo (revisions of initial versions 212 and final version selection) Logo (final version adjustments) 124 Business card 83 Letterhead 16 Social media: posts (5 templates) 62 and stories (4 templates) Cover page 46 Digital advertisement 24 Flyer 66 Total 1195 (19 h 55 min) 15 403 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Appendix D: Appendix D: Time measurement of CVI creation with AI Time measurement of CVI creation with AI Corporate visual identity elements Time measured in minutes Logo (entry of basic information) 1 Logo (parameter adjustments, 3x) 3 10 Logo (selection) 6 Business card 12 Cover page 10 Social media posts 14 Social media stories 11 Profile picture 3 Digital advertisement 14 Letterhead 16 Flyer 15 Total 105 (1 h 45 min) Corresponding author: ADDITIONAL DATA ABOUT AUTHORS Tanja MEDVED Corresponding author: University of Ljubljana, Faculty of Natural Sciences and Engineering, Chair of Information and Graphic Co-author(s): Arts and Technology Snežniška ulica 5 Tanja Medved Sara Mužar 1000, Ljubljana, Slovenija University of Ljubljana University of Ljubljana Faculty of Natural Sciences Faculty of Natural Sciences phone: 00386 40 454 643 and Engineering and Engineering e-mail: tanja.medved@ntf.uni-lj.si Chair of Information Chair of Information and Graphic University of Ljubljana and Graphic Arts and Technology Snežniška ulica 5 Snežniška ulica 5 Co-author(s): 1000, Ljubljana, Slovenija 1000, Ljubljana, Slovenija sm2841@student.uni-lj.si Sara MUŽAR tanja.medved@ntf.uni-lj.si Snežniška ulica 5 University of Ljubljana 1000, Ljubljana, Slovenija 00386 40 454 643 University of Ljubljana, Faculty of Natural Sciences and Engineering, Chair of Information and Graphic University of Ljubljana, Helena Gabrijelčič Tomc Faculty of Natural Sciences e-mail: sm2841@student.uni-lj.si and Engineering Chair of Information Helena GABRIJELČIČ TOMC and Graphic University of Ljubljana University of Ljubljana, Faculty of Natural Sciences and Engineering, Chair of Information and Graphic University of Ljubljana, Snežniška ulica 5 1000, Ljubljana, Slovenija 01/20 03 291 phone: 01/20 03 291 Snežniška ulica 5 1000, Ljubljana, Slovenija e-mail: helena.gabrijelcictomc@ntf.uni-lj.si helena.gabrijelcictomc@ntf.uni-lj.si 16 404 PACKAGING 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION PROSPECTS FOR THE FUTURE OF PRINTED PACKAGING PROSPECTS FOR THE FUTURE OF PRINTED PACKAGING IN THE IN THE CIRCULAR ECONOMY CIRCULAR ECONOMY Csaba Horváth and László Koltai1 1Óbudai University, Institute of Media Technology and Light Industry Engineering, Hungary Csaba Horváth, László Koltai Óbudai University, Institute of Media Technology and Light Industry Engineering Doberdó út 6. Budapest (1034) - Hungary, Abstract: The printed packaging market continues to evolve, driven by a number of macro factors. Concern for the environment and a commitment to protecting it has reached an all-time high, resulting in sustainability beco-Abstract: The printed packaging market continues to evolve, driven by a number of macro factors. Concern ming the primary driver of change for key players in the supply chain. The influence of consumer expectations on for the environment and a commitment to protecting it has reached an all-time high, resulting in sustainability journal articles and market reports, the authors present the key drivers of the packaging market: sustainability and Drawing on recent conference presentations, journal articles and market reports, the authors present the key drivers of the regulation, the growth of e-commerce, changing consumer attitudes and lifestyles, digitalisation and innovation. packaging market: sustainability and regulation, the growth of e-commerce, changing consumer attitudes and lifestyles, digitalisation and innovation. printing processes, smart packaging and communication devices. expectations on the development of printing and packaging is now very significant. There are also accelerating Drawing on recent conference presentations, developments in printing processes, smart packaging and communication devices. the development of printing and packaging is now very significant. There are also accelerating developments in becoming the primary driver of change for key players in the supply chain. The influence of consumer Keywords: Printed packaging, sustainability, digital printing, consumer attitudes in packaging, packaging inno- vation Keywords: Printed packaging, sustainability, digital printing, consumer attitudes in packaging, packaging innovation 1. INTRODUCTION 1. INTRODUCTION value of European printing is expected until 2027. But the printed packaging output is expected to grow till 2027 Europe remains a key region for the printing industry globally. Despite this, only moderate growth in the overall Europe remains a key region for the printing industry globally. Despite this, only moderate growth in the overall with yearly 1,7% (Figure 1). value of European printing is expected until 2027. But the printed packaging output is expected to grow till 2027 with yearly 1,7% (Figure 1). 2022 € 86.9 bn 2027 € 94.6 bn 10% 11% 10% 31% 10% 31% 10% 10% 23% 16% 15% 23% corrugated & solid fibre packaging corrugated & solid fibre packaging carton carton flexibile packaging flexibile packaging metal packaging metal packaging labels labels rigid plastic packaging rigid plastic packaging Overall Market CAGR (2022-2027) = 1,7% Figure 1: Figure 1: European Package & Label Printing Output by Type, 2022 and 2027 European Package & Label Printing Output by Type, 2022 and 2027 [% share by value, constant 2021 price and € exchange rate basis] (Halam, 2023) [% share by value, constant 2021 price and € exchange rate basis] (Halam, 2023) 1 406 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Data ( on Figure 1) covers both Western and Eastern Europe, including all EU-27 Member States plus the UK, Norway and Switzerland. Russia and Ukraine have not been included in the analysis due to the current high un-certainty in these markets due to the war. Values have been converted into Euro. Globally, packaging is a growing sector. This growth is driven by demographic changes and changing consumer Data ( on Figure 1) covers both Western and Eastern Europe, including all EU-27 Member States plus the UK, lifestyles. Populations are growing in almost every country in the world and there is a significant shift in the pro Norway and Switzerland. Russia and Ukraine have not been included in the analysis due to the current high -portion of people living in urban and rural areas. uncertainty in these markets due to the war. Values have been converted into Euro. Working-age people are now often referred to as „cash-rich and time-poor“, driving demand for packaging in areas consumer lifestyles. Populations are growing in almost every country in the world and there is a significant shift in the proportion of people living in urban and rural areas. Globally, packaging is a growing sector. This growth is driven by demographic changes and changing such as ready meals. Working-age people are now often referred to as "cash-rich and time-poor", driving demand for packaging in Growth is expected to stagnate in Europe. The e-commerce packaging market in Western Europe and Eastern areas such as ready meals. Growth is expected to stagnate in Europe. The e-commerce packaging market in Western Europe and Eastern Europe is estimated to reach a total of €11.8 billion in 2028 (Mordor Intelligence, 2023). Europe is estimated to reach a total of €11.8 billion in 2028 (Mordor Intelligence, 2023). Based on recent conference presentations, journal articles and market reports published by various Based on recent conference presentations, journal articles and market reports published by various international international trade associations, the key trends and drivers in the world of printed packaging can be identified trade associations, the key trends and drivers in the world of printed packaging can be identified as follows (Ra-as follows (Ragaert, 2023; Smithers Research, 2023; IMARC, 2023; Mordor Intelligence, 2023). gaert, 2023; Smithers Research, 2023; IMARC, 2023; Mordor Intelligence, 2023). - Digital printing - Digital printing - Sustainability and regulation - Sustainability and regulation - Growth of e-commerce - Growth of e-commerce - Digitalisation and innovation - Digitalisation and innovation - Consumer attitudes - Consumer attitudes 2. DIGITAL PRINTING 2. DIGITAL PRINTING Although printing is perceived to be going through difficult times, it is in fact a highly competitive and dynamic busi-business, especially in the packaging sector. There are huge expectations for the development of digital Although printing is perceived to be going through difficult times, it is in fact a highly competitive and dynamic ness, especially in the packaging sector. There are huge expectations for the development of digital printing, both printing, both inkjet and electrophotography. Digital printing is increasingly used to print labels, corrugated, inkjet and electrophotography. Digital printing is increasingly used to print labels, corrugated, cartons, flexible, cartons, flexible, rigid, plastic, metal and glass packaging. In 2020, as the global Covid pandemic disrupted all rigid, plastic, metal and glass packaging. In 2020, as the global Covid pandemic disrupted all aspects of human aspects of human life, digital packaging volumes soared as suppliers were able to respond quickly to changing life, digital packaging volumes soared as suppliers were able to respond quickly to changing demands. demands. Digital printing is gaining ground over analogue printing methods such as lithography, flexography, gravure and Digital printing is gaining ground over analogue printing methods such as lithography, flexography, gravure embossing as it creates new opportunities - especially for the emerging craft sector (Figure 2). Technological and embossing as it creates new opportunities - especially for the emerging craft sector (Figure 2). advances have enabled converters and manufacturers to install equipment that is cost-effective and highly pro Technological advances have enabled converters and manufacturers to install equipment that is cost-effective -ductive while meeting the expected quality requirements. and highly productive while meeting the expected quality requirements. corrugated & solid fibre packaging cartons flexibile packaging value 0 2 4 6 8 10 12 14 16 18 20 volume [%] Figure 2: Figure 2: Growth in European digital package printing output by key pack type, 2022-2027 (Smithers, 2023) Growth in European digital package printing output by key pack type, 2022-2027 (Smithers, 2023) 407 2 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Digital printing allows for greater flexibility, helping packaging manufacturers and converters to meet the increas-ingly tight schedules of their customers. The ability to print variable content enables brands to create new, in-novative solutions, delivering higher levels of engagement and new customer experiences that increase brand effectiveness and value (Heidelberger Druckmachinen AG, 2022). Digital printing allows for greater flexibility, helping packaging manufacturers and converters to meet the increasingly tight schedules of their customers. The ability to print variable content enables brands to create Analogue Print is responding to this challenge with its own developments to improve the performance of offset, new, innovative solutions, delivering higher levels of engagement and new customer experiences that increase flexo and gravure printing for shorter runs, including fixed colour gamut printing, automatic colour correction and brand effectiveness and value (Heidelberger Druckmachinen AG, 2022). registration, streamlined plate and roll preparation, robotic plate loading and many other improvements. Analogue Print is responding to this challenge with its own developments to improve the performance of offset, flexo and gravure printing for shorter runs, including fixed colour gamut printing, automatic colour correction and registration, streamlined plate and roll preparation, robotic plate loading and many other improvements. 2.1 Market drivers for adoption of digital print for packaging Among the factors driving the growth of digital printing, the trend towards lower print runs (batch sizes) plays a ma 2.1 Market drivers for adoption of digital print for packaging -jor role. Differences in set-up costs when producing shorter runs can contribute significantly to variations in cost Among the factors driving the growth of digital printing, the trend towards lower print runs (batch sizes) plays per print between printing processes. On the other hand, for large print runs, these set-up costs are significantly a major role. Differences in set-up costs when producing shorter runs can contribute significantly to variations reduced and the costs of consumables used - ink, coating and other consumables - dominate. in cost per print between printing processes. On the other hand, for large print runs, these set-up costs are The ‚Amazon‘ effect - significantly reduced and the costs of consumables used - ink, coating and other consumables - dominate. The need and expectation for same-day and next-day delivery is widespread, but not typical and finishing services (Figure 3). This technology will be exploited not only by craft brands, but also by large com typical in the labelling and packaging sector. It is expected that by 2027, many converters will offer on-demand -printing and finishing services (Figure 3). This technology will be exploited not only by craft brands, but also in the labelling and packaging sector. It is expected that by 2027, many converters will offer on-demand printing The 'Amazon' effect - The need and expectation for same-day and next-day delivery is widespread, but not Environmental benefits will come from less set-up waste, printing accurate quantities on demand and eliminating by large companies that will be able to move to smaller and more frequent orders with changes to meet panies that will be able to move to smaller and more frequent orders with changes to meet consumer demand. minimum order quantities (Guga, 2023). consumer demand. Environmental benefits will come from less set-up waste, printing accurate quantities on demand and eliminating minimum order quantities (Guga, 2023). Figure 3: Figure 3: Personalized packaging (Hallam, 2023) Personalized packaging (Hallam, 2023) 2.2 Supply chain changes 2.2 Supply chain changes Most packaging is produced by processors and delivered to manufacturers or packers/fillers and then to distribu Most packaging is produced by processors and delivered to manufacturers or packers/fillers and then to -tion chains. Some big-name brands are re-producing packaging in-house, using digital printing to provide greater distribution chains. Some big-name brands are re-producing packaging in-house, using digital printing to flexibility and versatility while controlling costs. Digital technology allows printing to be brought closer to the con provide greater flexibility and versatility while controlling costs. Digital technology allows printing to be brought - distribution centres where personalised packaging can be tailored to size on demand. Packaging is a direct cost manufacturers and in distribution centres where personalised packaging can be tailored to size on demand. Packaging is a direct cost to brands, retailers and distributors, adding promotional messages and advertising sumer and there are examples of digital printing being used for on-demand production at manufacturers and in closer to the consumer and there are examples of digital printing being used for on-demand production at into a revenue generator (Hack, 2023).. can turn packaging from a cost into a revenue generator (Hack, 2023).. to brands, retailers and distributors, adding promotional messages and advertising can turn packaging from a cost 2.3 Market barriers for adoption of digital print 2.3 Market barriers for adoption of digital print Capability - Digital print successfully replicates most analogue print, except for some spot colours, special-Capability effect inks and coatings. Hybrid systems (and HP Indigo) can handle the special requirements. In the future - Digital print successfully replicates most analogue print, except for some spot colours, special-effect inks and coatings. Hybrid systems (and HP Indigo) can handle the special requirements. In the future more digital more digital speciality inks will become available, with alternative methods such as Actega Ecoleaf used to inks and foiling for example. Cost - Much digital is significantly higher cost than analogue new high-performance machines are changing this with lower TCO ( speciality inks will become available, with alternative methods such as Actega Ecoleaf used to replace metallic replace metallic inks and foiling for example. Total Cost of Ownership). Price premium for inks falls with bulk supply direct from the Cost equipment manufacturer, significantly reducing ink cost, particularly for water-based inkjet. Further economies - Much digital is significantly higher cost than analogue new high-performance machines are changing this with lower TCO ( of scale drive down the cost of equipment and the necessary control systems and workflow software. Total Cost of Ownership) . Price premium for inks falls with bulk supply direct from the equipment 408 3 29–30 May 2025, Ljubljana, Slovenia manufacturer, significantly reducing ink cost, particularly for water-based inkjet. Further economies of scale drive down the cost of equipment and the necessary control systems and workflow software. 3. SUSTAINABILITY AND REGULATION Sustainability is currently the number one concern of consumers and governments, and a top target for the packaging industry and lobby groups. From a printing perspective, digital printing eliminates analogue mould making technology and the associated waste. It will also eliminate potential redundancies in the supply chain. By 2027, it is expected that scientifically rigorous life-cycle analysis measuring key impacts will be available to determine the true performance of digital printing. If there are demonstrable benefits (and there are expected to be), these will provide a significant boost to digital packaging (Nogueira, 2023). Sustainability is also a key driver in the packaging industry. All stakeholders in packaging: raw material suppliers, processors, distributors, brand owners, retailers and consumers are increasingly focused on aligning their packaging and products with the circular economy (Desgrees du Lou, 2023). 3.1 Circular packaging The main objective of the circular economy is to keep valuable resources in use and to use them over as many life cycles as possible. This implies a gradual decoupling of economic activity from the consumption of finite (fos-sil) resources and the diversion of waste out of the system. Initiatives such as EU Vision 2020 promote this new model by extending product life, creating more durable products, reducing manufacturing waste, encouraging consumers to recycle, promoting reuse and strengthening the end market for waste. The transition to a circular economy is not just about making adjustments to reduce the negative impacts of a line-ar economy. Rather, it is a fundamental change that builds long-term resilience, creates business and economic opportunities, and delivers both environmental and social benefits (Munroe, 2023). The Circular Economy Action Plan requires EU countries to ensure that packaging placed on the market complies with the essential requirements of Annex II of the Packaging and Packaging Waste Directive: • minimise the weight and volume of packaging to achieve the required level of safety, hygiene and accepta- bility for consumers; • reducing the content of hazardous substances and materials in packaging materials and their components; • the design of reusable or recyclable packaging. 3.2 Carbon footprint Reducing emissions from the production and printing of packaging is at the top of the agenda for industry leaders as they strive to achieve net-zero targets. However, this is a challenging task and the market is currently suffering from a deluge of greenwashing - claims made against products that are factually untrue or unsubstantiated (Hal-lam, 2023). The main way to measure the carbon footprint of a label or packaging solution is to carry out a full life cycle analysis (LCA). This is a valuable tool if the methodology is sound and the results are third-party verified, but the results should never be taken at face value. The choice of supplier can be as important a decision as the choice of material, as carbon emissions can vary widely between factories. Suppliers should be aware that carrying out LCA can often be a slow and costly process. Sustainability is at the forefront of the European Commission‘s regulatory framework for packaging and labelling. This legislation is becoming more stringent and stakeholders in this area need to carefully comply with the require-ments already in place. 409 29–30 May 2025, Ljubljana, Slovenia The EU has developed a comprehensive strategy for regulatory guidelines throughout the life-cycle of consumer packaging. The strategy aims to develop an integrated circular economy model that favours re-use, recycling and reduction. It proposes some anti-plastic sense, but this element focuses on single-use plastic articles rather than on the material itself. Climate change mitigation provides a strong backdrop for setting policy priorities. 3.3 Draft Packaging and Packaging Waste Regulation (PPWR) As its name suggests, the PPWR (Packaging and Packaging Waste Regulation) is a draft regulation, which has been developed from an earlier version known as the PPWD, which was a directive under EU law. PPWR will be legally enforced across the EU by the end of 2024. The PPWR and packaging is part of the ‚European Green Deal‘, a legal framework that aims to make the region carbon neutral by 2050 (Desgrees du Lou,2023). The proposed requirements of the PPWR will impose greater responsibility on those who place packaging on the market through Extended Producer Responsibility (EPR). Smithers has a ready market report on this very topic. The food, grocery and beverage industries are expected to be most affected by these developments in PPWR. The proposal on PPWR will go through the EU‘s normal scrutiny procedure, where further amendments will be made. The current proposal is based on the PPWD impact assessment, which identified three main issues to be addres-sed. 1. Increasing packaging waste generation. 2. Barriers to recycling and reuse of packaging waste. 3. The low recycling quality of plastic packaging and the use of secondary raw materials. The overall objective of the proposal is „to reduce the negative environmental impact of packaging and packaging waste while improving the functioning of the internal market“. The objectives are as follow. • All packaging materials to be recyclable by 2030. • To reduce packaging waste by 15% by 2040 (per capita per Member State compared to 2018). • By 2029, countries should establish a deposit return scheme (DRS) with a collection rate of 90%. • By 2025, 65% of all packaging waste (by weight) should be recycled. • Climate neutrality in the packaging sector by 2050. 3.4 Other EU Legislation influencing the label & packaging markets Action Plan for the Circular Economy An outline of the EU’s efforts to develop a sustainable, low-carbon, resource-efficient and competitive economy, adopted in 2015. It places packaging waste in a continuum from production to consumption to waste management to recoverable or recyclable resources. It presents a basic legislative blueprint, including not only regulation of the private sector, but also government investment and measurement of progress towards targets. Compliance criteria for environmental claims Requires that waste management does not endanger human health or harm the environment, pose a risk to water, air, soil, plants or animals, cause a nuisance through noise or odour, or adversely affect the landscape or places of special interest. European strategy for plastics in the circular economy The Plastics Strategy is part of the EU’s transition to a more ‘circular’ economy. Its aim is to improve “the way plastics are currently produced, used and disposed of”, as the status quo fails to reap the economic benefits of a more circular approach and is damaging the environment. The strategy calls for all plastic packaging on the EU market to be reusable or recyclable in a cost-effective way by 2030. 410 29–30 May 2025, Ljubljana, Slovenia The Single-Use Plastics Directive (SUP Directive) In February 2021, the European Parliament called on the Commission to consider further measures, such as amending the Single-Use Plastics Directive to ensure that single-use plastics are replaced by reusable products wherever possible. The Commission was also called on to develop standards for reusable packaging and the replacement of single-use packaging. The Strategic Environmental Assessment (SEA) Directive (2001/42-EC) sets targets for recycled content for cer-tain plastic packaging (drinks bottles), while national plastics taxes linked to the Directive reward recycled content for certain single-use plastics. Labelling requirements Labels and packaging are increasingly subject to legislation, requiring more information and, in some sectors, coding to reduce the possibility of counterfeiting. The legislation extends beyond the pharmaceutical industry to consumer goods. Unique codes and tracking and tracing using a simple phone camera app for authentication are being offered as a method of authentication and as a logistical tool for distribution. Many high-value products can be authenticated, although for high-volume, low-value products, some brands are concerned about potential litigation over counterfeit products. 4. THE GROWTH OF E-COMMERCE The unprecedented growth in e-commerce activity since 2020 has led to a proportionately large increase in de-mand for transit packaging. This has been coupled with external pressure on retailers from consumers, NGOs and government regulation to reduce the environmental impact of e-commerce packaging. Efforts have focused on: reducing weight; reducing raw material use; increasing recycled content; and eliminating empty spaces. E-retail-ers are looking at material substitution (plastic to paper) and reusable packaging options. The global e-commerce packaging market was estimated to be worth $63.60 billion in 2022, growing at an aver-age annual rate of 20.0% since 2017. However, global value growth of 12.5% in 2022 is significantly slower than the rates experienced globally during the peak of the Covid-19 pandemic and the boom in online shopping. Further growth is expected in the global e-commerce packaging market as e-commerce activity continues to grow, but now at a slower pace, with value sales forecast to grow at a CAGR of around 9.8% through to 2027. 4.1 Key factors shaping the e-com packaging market 1. Environmental concerns about plastics have a negative impact on polybags/bags, both in terms of raw material and overall life cycle. In the EU, retailers are required to use bags with at least 30% recycled content to comply. 2. The growth of paper-based postal parcels will offset some of the slowing growth of polybags. 3. Improved 3D batch scanning technology and fanfold corrugated automated box making machines will improve box production efficiency and reduce empty spaces. 4. Demand for protective packaging in larger formats will remain stable, but smaller formats are not expected to keep pace with growth in other packaging types due to concerns about recyclability and a decline in some core product applications. 4.2 Consumers expect high quality printed (and sometimes personalised) packaging High levels of consumer expectation now extend to packaging, and they can feel disappointed by e-retailers without a well planned and executed packaging strategy. Packaging is often the brand’s first physical contact with the consumer and judgement is often cast at this stage. In a Shorr Packaging survey, 51% of respondents stated that printed or personalised packaging made them feel that the product inside was more valuable. In conventional retail, consumers hold a product as part of the purchase decision process, whereas online consumers only expe-rience a physical product after receipt. Digital printing has benefits when it comes to personalisation as individual print designs can be made to match the profile of individual customers. This can be achieved when the brand owner/retailer has a well-developed customer database (‘big data’). 411 29–30 May 2025, Ljubljana, Slovenia When it comes to flexo the improvements in board qualities, such as white top kraftliners, means that brands can implement what is being termed ‘Packvertising’ – i.e. printing their corrugated boxes with high quality images to promote the brand and enhance the unboxing experience (Hallam, 2023). 5. DIGITALISATION AND INOVATION One of the most significant impacts of track and trace packaging on the global market is blockchain technology, which is likely to continue to grow in the future. 5.1 Leveraging blockchain for track and trace packaging The blockchain technology can be described as a distributed and immutable ledger that can record transactions, track assets and provide greater transparency across the throughout the supply chain. With blockchain tech-nology, data is stored in interconnected blocks that are time-stamped and tamper-proof. Combined with other technologies, such as near field communication (NFC) or the Internet of Things, blockchain technology allows consumers to access the full history of a product, providing significant benefits in areas such as anti-counterfeiting and record-keeping (Gegeckienė, 2022). Advocates of blockchain technology believe it offers significant benefits to companies and organisations seek-ing traceability, anti-counterfeiting and brand authentication solutions. Much of its appeal can be attributed to its ability to improve record-keeping and thereby improve supply chain and inventory management. As more and more people now have internet-enabled mobile devices such as smartphones, consumers’ ability to quickly and conveniently check the authenticity of goods or supply chain traceability using technologies such as QR codes has increased significantly. For consumer products such as food, blockchain technology is seen as a useful tool to combat contamination and threats to consumer safety, while also offering benefits in terms of innovation and intellectual property (IP), as it is clearer what information has been produced, when and by whom. 5.1 Smart packaging developments There are several recent examples of smart packaging being used to add value to product offerings. • Accenture recently partnered with a European luxury brand to create a virtual retail storefront where consumers could enter by scanning or activating the smart packaging of a product. Within the metaverse, consumers co-uld interact with the digital equivalent of the product - the information generated by consumer interactions can be captured and used to inform areas such as sales and manufacturing. • Developments in smart packaging for the pharmaceutical industry include new time-temperature technologies that increase safety and extend the shelf life of certain products, such as vaccines. In May 2022, Essentra Pac-kaging and Advanced Material Development (AMD) announced that they will collaborate to develop next-ge-neration solutions within the industry to improve patient safety. • During 2021, the US and Chinese authorities announced that they will develop enhanced food traceability systems to improve food safety through the introduction of smart packaging solutions. • The adoption of smart packaging with tracking capabilities can often serve to improve the competitiveness of companies in the logistics industry by providing them with information that can help reduce waste and costs and improve productivity. • A leading Australian company in the smart packaging market is Laava, which specialises in product authen- tication technology. Its portfolio includes Smart Fingerprints, which uses patented optical technology to apply unique and randomly generated images to labels and other packaging, and is being promoted as an alternative to QR codes. Smart Fingerprints technology has been used on more than two million products and has been adopted in both food and beverage applications in recent years (’t Hart, 2023). 412 29–30 May 2025, Ljubljana, Slovenia 5.2 Packaging format innovation There are many worthy examples that could be included but the three most prominent developments over the beginning of this decade years have been (Lippitsch, 2023) • Paper mailing bags for e-commerce • Paper bottles for the beverage and homecare sectors • Dry moulded pulp in the foodservice and pharma markets 6. CONSUMER ATTITUDES Consumers have a negative perception of single-use plastic packaging, which has encouraged the development of alternative materials and packaging. A good example of this is the food sector, where brand owners and retail chains are constantly experimenting with substitutes for single-use plastic packaging, such as compostable bags, paper bags and cellulose nets. It is expected that the recent trend of replacing single-use plastic packaging with reusable renewable materials will continue (Oliver, 2022). 6.1 Consumers are driving the demand for recyclable and compostable packaging Partly as a response to the media’s portrayal of the harmful effects of plastic on the environment, consumers are becoming more aware and passionate about the impact of packaging on the environment. Consumer advocacy is driving action by brand owners and national governments. Many European countries have banned single-use plastic products such as plastic straws, bags, coffee cups and other non-recyclable products. There is also a growing interest in reusable products and efforts are being made to increase recycling in waste collection. The need for education on the need and opportunities for sustainability has also been highlighted. 6.2 Consumers do not like oversized packaging Consumers are becoming increasingly concerned about the use of oversized packaging for home delivery, forcing brand owners and retailers to respond to this demand with improvements. Consumers expect printed packaging to take this into account. Sustainable printed packaging can go a long way to adding value to the unboxing experience for the consumer. 7. ACKNOWLEDGEMENTS The authors would like to thank the speakers at the conference ‘Shaping the future with packaging’, organised by INTERGRAF and FTA Europe (European Printing Associations), 9-10 March 2023, Brussels, for making their presentations available to us. 413 29–30 May 2025, Ljubljana, Slovenia 8. REFERENCES Desgrees du Lou, Maja: Proposal for Regulation on Packaging & Packaging Waste (presentation); Integraf – FTA Europe: Shaping the Future with Packaging Conference, Brussels, March 9th,2023 Guga, Ștefan - Strătilă, Tudor: Amazon and the packaging, publishing and printing industries: an overview, Syntex – UNI Europe – Intergraf, 2023, p.54 Gegeckienė, Laura – Venytė, Ingrida – Karpavičė, Justina – Tambo, Torben – Vaitasius, Kęstutis – Pauliukaitis, Darius: Near field communication (NFC) technology int he packaging industry; GRID Internal Symposium on Graphic Engineering and Design – 2022, University of Novi Sad, Serbia, Proceedings, pp. 495 – 501 Hack, Michael –Ward, Jonathan: Rethinking Packaging: A DHL perspective onthe future of packaging in the logistics industry, DHL Customer Solutions & Innovation, Trisdorf, Germany, 2023, p.38 Hallam, Tom: Market Insights: Eurpean Packaging Sector (presentation); Intergraf – FTA Europe: Shaping the Future with Packaging Conference, Brussels, March 9th,2023 Heidelberger Druckmachinen AG: White paper: Packaging printing 4.0. Digitization and its impact on sustainability, agility, and growth. Heidelberg, Germany, 2022. p.11 IMARC: Advanced Packaging Market: Global Industry Trends, Share, Size, Growth, Opportunity and Forecast 2023-2028, Market report, ID: SR112023A6250, 2023 Lippitsch, Susanne: Shaping Packaging for the Future (presentation), Intergraf – FTA Europe: Shaping the Future with Packaging Conference, Brussels, March 10th,2023 Mordor Intelligence: Europe Printed Packaging Market Size & Share Analysis - Growth Trends & Forecasts (2023 - 2028) (https://www. mordorintelligence.com/industry-reports/europe-printed-packaging-market) Last accessed on Oct. 1, 2023. Munroe, Olga: Sustainable Strategies of UK Reailers – Case Studies (presentation); Intergraf – FTA Europe: Shaping the Future with Packaging Conference, Brussels, March 9th,2023 Nogueira, Francisco: World Without Waste (presentation), Intergraf – FTA Europe: Shaping the Future with Packaging Conference, Brussels, March 9th, 2023 Oliver, Mikah - Vrabič-Brodnjak, Urška – Jestratijevic, Iva: Consumer’s socio-Demographics influence between purchase intention and actual behavior of environmentaly friendly grocery packaging, GRID Internal Symposium on Graphic Engineering and Design – 2022, University of Novi Sad, Serbia, Proceedings, pp. 539-546 Ragaert, Peter: Sustainable of Food Packaging: A Muscipliniary Approach (presentation); Intergraf – FTA Europe: Shaping the Future with Packaging Conference, Brussels, March 10th,2023 Smithers Research: An Overview of the European Printed Packaging Market; Market report, 2023 ’t Hart, Jan: Watermark Holly Grail 2.0 (presentation); Intergraf – FTA Europe: Shaping the Future with Packaging Conference, Brussels, March 10th,2023 ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author Dr. habil. Csaba Horváth Dr. habil. László Koltai professor dean, associate professor Rejtő Sándor Rejtő Sándor Faculty of Light Industry Faculty of Light Industry Óbuda University Óbuda University and Environmental Engineering and Environmental Engineering Institute of Media Technology and Light Industry Engineering Institute of Media Technology and Light Industry Engineering Dobersó út 6 Dobersó út 6 1034 Budapest, Hungary 1034 Budapest, Hungary +36 70 6306550 koltai.laszlo@uni-obuda.hu +36 30 9355840 horvath.csaba@uni-obuda.hu 414 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION PAPER BAGS MADE FROM ANNUAL PLANTS Ana Štrucelj1 and Klemen Možina1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Durable paper is essential for the production of durable paper bags. Although sufficient wood is avail-able in Europe, the technology for obtaining cellulose fibres from annual plants is also of great interest to inventors and manufacturers of cellulose fibres. The advantages of annual plants are easier delignification, lower water con-sumption and the use of agricultural by-products that would otherwise have to be disposed of in other ways. The main disadvantage of obtaining cellulose fibres from annual plants is that the plants are only available at certain times of the year, which requires large storage capacities. We compared three types of paper produced in Europe that are used to make paper bags. The first paper sample contained only primary wood cellulose fibres, the sec-ond sample contained fibres from grass, wood and secondary fibres and the third sample contained cellulose fi-bres from fallen leaves and secondary cellulose. By comparing the physical-mechanical properties (tear strength, burst strength, tensile strength, sound propagation speed), we wanted to determine whether paper made from annual plant fibres could replace paper made from wood cellulose in the production of paper bags. We assumed that paper made from wood cellulose would be more resistant than others because the wood fibres are longer and therefore improve the physical-mechanical strength of the paper. We were able to confirm this hypothesis, as the paper with primary wood pulp performed better in all measurements except for tear strength, where the grass and wood fibre paper performed better. The paper containing no wood cellulose fibres performed the worst of all three papers tested. Even though the production of paper from annual plant fibres is a welcome innovation, it unfortunately cannot yet replace wood cellulose paper. Keywords: paper bags, cellulose, annual plants, physical-mechanical properties 1. INTRODUCTION Shopping bags are the „necessary evil“ of modern consumer society. The formerly ubiquitous polythene bags have now been replaced by reusable bags for more conscious shopping. Paper bags have established themsel-ves as an alternative to plastic bags. Paper for carrier bags must have sufficiently good physical and mechanical properties to withstand the stresses that occur firstly during printing and finishing and then during primary use. Annual plants are widely used as a source of cellulose fibres, especially in tropical countries. In our country, the technology for processing annual plants into cellulose fibres has not yet been massively developed as we have sufficient quantities of wood. Cellulose fibres for packaging paper are obtained from the trunks of coniferous and deciduous trees using the sulphate process. The fibres obtained give the paper excellent physical and mechanical properties, but the processing is energy and technology intensive. There is also a growing trend towards the con-servation of forests and the looking for other pulp sources that are easier to process and have less impact on the environment. Two alternatives have emerged in Europe, namely the production of cellulose fibres from grass and leaves. These two alternative raw materials are already being used on an industrial scale for the production of pa-per and carrier bags. In our research, we determined the physical-mechanical properties of three different papers for carrier bags and established whether papers made from the fibres of annual plants can replace papers made from wood cellulose fibres on an equal footing in this area. Today, paper made from annual plants is once again becoming an alternative to paper made from cellulose fibres obtained from thick trees. This is particularly true in countries where the amount of wood is limited due to natural conditions or forest protection, i.e. as a more envi-ronmentally friendly alternative it is also spreading in countries that otherwise have sufficient quantities of wood. 415 29–30 May 2025, Ljubljana, Slovenia There are several reasons for this: − reduced availability of wood, − greater availability of annual plants, − faster growth of annual plants and − growth of the paper industry. The area of forests worldwide is decreasing for various reasons, to which the paper industry also contributes. Despite the tendency to switch to other fibres, it is still necessary for the time being to add wood fibres in order to achieve the desired properties. In areas where there are no forests due to climatic conditions, the lack of wood is an even greater problem. Paper consumption will most likely only increase due to the growth of the world‘s population and the desire for education (Ainun, 2023). Although the extinction of paper as a medium has long been predicted with widespread digitalisation, it is becoming increasingly clear that this is not true (Možina, 2017). Paper consumption per capita is increasing, and text written on paper is permanent, has greater significance and outlasts all digital recording media, many of which we have already had to replace in the age of digitalisation. The annual plants from which paper fibres are obtained can be divided into three groups depending on their origin: − agricultural by-products (e.g. wheat or rice straw, bagasse), − specially cultivated plants (e.g. jute, hemp, kenaf) and − naturally occurring plants in the environment (e.g. bamboo, reeds). The extraction of fibres from annual plants can have its own specific problems. They usually have to be harvested by hand, which involves considerable costs. Different plants can only be harvested for a short period each year, so it is necessary to ensure sufficient quantities for uninterrupted production and to provide suitable storage (vo-lume, possibility of spontaneous combustion). We must bear in mind that stored products spoil in the presence of moisture and micro-organisms, which alter their physical, chemical and visual properties. The annual harvest varies from year to year and depends on weather conditions, so the same quantity and quality cannot be gua-ranteed every year. The targeted cultivation of plants for the production of fibres is controversial, as it consumes resources and agricultural land that could otherwise be used for food production. In order to utilise plants that occur in the natural environment, it is also necessary to carefully consider the impact of mass harvesting on other factors in their natural environment. From an environmental perspective, it therefore makes the most sense to use plants or parts of plants that are by-products or unwanted in the environment and would otherwise have to be composted, incinerated or utilised elsewhere. By focusing on the use of fibres from annual plants, such as straw, they are working in countries that have large agricultural areas but little forest. Ukraine, for example, imports large quantities of wood or recycled paper to produce paper (Tomšič, 2020). In Ukraine, the idea was born to produce paper from the leaves of trees in the urban environment. Table 1 shows the weight percentages of annual plants used for paper production. Table 1: Proportion of annual plants for paper production (Bajpai, 2021) Matrial Proportion [%] straw 44 bagasse 18 reed 14 bamboo 3 other 21 In Asia, the use of annual plants for the production of paper fibres is widespread, mainly due to the lack of wood resources. China leads the way here, where as much as two-thirds of the world‘s paper material is produced from non-wood sources. In the USA and Europe, despite the presence of forests, annual plants are used as a source of cellulose fibres to a limited extent, as they reduce the costs of disposing of agricultural by-products (straw, corn stalks) and reduce the impact of their destruction on the environment (Bajpai, 2021). 416 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL 2.1 Materials and methods The measurements were carried out on three paper samples from which paper bags are manufactured. All the papers listed are produced industrially on a paper machine. The samples for kraft and grass paper were taken directly from the paper roll, while the paper made from fallen tree leaves was taken from bags that had already been made. Kraft paper and grass paper were provided to us by Dama d.o.o., where they are used to make carrier bags. We purchased paper bags made from the pulp of fallen tree leaves from the manufacturer Releaf paper, Ukraine. We selected papers that have a similar basis weight and are all intended for the production of paper bags. The three selected papers (Table 2) are suitable for contact with food and, as long as they are not contami-nated, can be disposed of normally in waste paper and recycled further. Table 2: Description of paper samples Paper Producer G [g/m2] Description sample S1 Unbleached, machine-made, contains only kraft cellulose fib-Mondi 110 res, no secondary fibres (Gregor Svetec, 2020) S2 Contains grass fibres, wood and secondary cellulose fibres, Creapaper 110 non-glossy and opaque, with a distinct smell of dry grass S3 It contains fibres from fallen tree leaves and secondary cellu-Releafpaper 120 lose fibres We used the following methods to analyse the properties: − basic properties (thickness, basis weight, density, specific volume and moisture content) and − physical-mechanical properties (tear strength and tear index (Schopper), tear strength and tear index (Elmen- dorf), sound pulse propagation velocity (PPM-5R), tear strength, elongation and tear length, tensile strength, work of rupture, tensile absorption energy and the corresponding index (Instron 6022), modulus of elasticity. 417 S1 Mondi 110 fibres, no secondary fibres (Gregor Svetec, 2020) S2 Contains grass fibres, wood and secondary cellulose fibres, Creapaper 110 non-glossy and opaque, with a distinct smell of dry grass 29–30 May 2025, Ljubljana, Slovenia It contains fibres from fallen tree leaves and secondary S 3 Releafpaper 120 cellulose fibres We used the following methods to analyse the properties: 3. RESULTS WITH DISCUSSION − − basic properties (thickness, basis weight, density, specific volume and moisture content) and physical-mechanical properties (tear strength and tear index (Schopper), tear strength and tear 3.1 Basic properties index (Elmendorf), sound pulse propagation velocity (PPM-5R), tear strength, elongation and tear length, tensile strength, work of rupture, tensile absorption energy and the corresponding index We measured the basic properties of the paper and thus described the paper samples for paper bags included in (Instron 6022), modulus of elasticity. the study (Table 3). 3. RESULTS WITH DISCUSSION 3.1 Basic properties Table 3: Basic properties. We measured the basic properties of the paper and thus described the paper samples for paper bags included in the study (Table 3). G [g/ ρ [kg/ ν t [mm] m 2 ] m 3 ] [cm 3 /g] MC [%] Table 3: Basic properties. 0.151 107.9 713 1.40 6.4 t [mm] G [g/m 2 ] ρ [kg/m3] ν [cm3/g] MC [%] S1 S 0.003 1.5 16 0.03 1.3 x x � 0 . 151 107 .9 713 1. 40 6.4 CV 2.00 1.42 2.23 2.20 20.11 S1 S x 0 . 003 1. 5 16 0 . 03 1. 3 0.185 114.6 622 1.61 4.8 CV 2. 00 1.42 2. 23 2. 20 20 .11 S2 S 0.011 2.4 34 0.09 1.9 x x � 0 . 185 114.6 622 1.61 4.8 CV 6.12 2.13 5,44 5.51 39.37 S2 S x 0 . 011 2.4 34 0 . 09 1.9 0.229 120.4 526 1.90 5.6 CV 6.12 2. 13 5,44 5 . 51 39 . 37 S3 S 0.009 1.3 21 0.08 1.1 x x � 0 .229 120 .4 526 1. 90 5 .6 CV 3.75 1.07 3,93 4.03 18.81 S 3 S x 0 . 009 1. 3 21 0 . 08 1.1 CV 3.75 1.07 3,93 4.03 18.81 Contrary to expectations, the smallest deviation in terms of grammage is found in S3 (1.07%), as it looks the least Contrary to expectations, the smallest deviation in terms of grammage is found in S3 (1.07%), as it looks homogeneous of all three (Figure 1). The inhomogeneity of the paper is an undesirable property as its properties the least homogeneous of all three (Figure 1). The inhomogeneity of the paper is an undesirable property are also uneven due to the non-uniform internal structure. In the paper where the fibre concentration is higher, as its properties are also uneven due to the non-uniform internal structure. In the paper where the fibre fibre bundles (haze) are visible. This is due to the non-uniformity of the paper suspension and is unavoidable to concentration is higher, fibre bundles (haze) are visible. This is due to the non-uniformity of the paper a certain extent. suspension and is unavoidable to a certain extent. S1 S2 S3 Figure 1: Cloudiness of paper bags specimens Figure 1: Cloudiness of paper bags specimens 3 418 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 3.2 Physical-mechanical properties 3.2.1 Bursting strenght and burst index 3.2 Physical-mechanical properties 3.2.1 Bursting strenght and burst index 3.2 Physical-mechanical properties As can be seen in Figure 2, S1 cracked at 280 kPa on side A and 264 kPa on side B, whereas the bursting strength As can be seen in Figure 2, S1 cracked at 280 kPa on side A and 264 kPa on side B, whereas the 3.2.1 Bursting strenght and burst index of S2 was twice as high, namely 127 kPa on side A and 116 kPa on side B. S3 had an even lower bursting stren-bursting strength of S2 was twice as high, namely 127 kPa on side A and 116 kPa on side B. S3 had an gth, which was 68 kPa on side A and 80 kPa on side B (Figure 2). S1 achieved a better result because it contains As can be seen in Figure 2, S1 cracked at 280 kPa on side A and 264 kPa on side B, whereas the even lower bursting strength, which was 68 kPa on side A and 80 kPa on side B (Figure 2). S1 achieved only primary cellulose fibres, which are longer than secondary ones. We can also infer a higher content of fibres bursting strength of S2 was twice as high, namely 127 kPa on side A and 116 kPa on side B. S3 had an a better result because it contains only primary cellulose fibres, which are longer than secondary ones. even lower bursting strength, which was 68 kPa on side A and 80 kPa on side B (Figure 2). S1 achieved from coniferous trees, which are longer than fibres from annual plants and deciduous trees, as is the case with We can also infer a higher content of fibres from coniferous trees, which are longer than fibres from a better result because it contains only primary cellulose fibres, which are longer than secondary ones. S2, which contains grass fibres and wood fibres, so its bursting resistance is lower (127 and 116 kPa), but still annual plants and deciduous trees, as is the case with S2, which contains grass fibres and wood fibres, We can also infer a higher content of fibres from coniferous trees, which are longer than fibres from higher than S3 (68 and 80 kPa), which does not contain pimary cellulose fibres from trees. As can be seen from so its bursting resistance is lower (127 and 116 kPa), but still higher than S3 (68 and 80 kPa), which annual plants and deciduous trees, as is the case with S2, which contains grass fibres and wood fibres, the bursting index, the grammage, i.e. the fibre composition and its source, plays the greatest role. does not contain pimary cellulose fibres from trees. As can be seen from the bursting index, the so its bursting resistance is lower (127 and 116 kPa), but still higher than S3 (68 and 80 kPa), which grammage, i.e. the fibre composition and its source, plays the greatest role. does not contain pimary cellulose fibres from trees. As can be seen from the bursting index, the grammage, i.e. the fibre composition and its source, plays the greatest role. Figure 2: Bursting strenght – Schopper Figure 2: Bursting strenght – Schopper Figure 2: Bursting strenght – Schopper 3.2.2 Tear strenght – Elmendorf The results of the tensile strength measurements for CD are in all cases higher (592 mN for S1, 606 mN for S2 for S2 and 469 mN for S3) than for MD (481 mN for S1, 496 mN for S2 and 418 mN for S3), which is to The results of the tensile strength measurements for CD are in all cases higher (592 mN for S1, 606 mN be expected to a certain extent, i.e. due to anisotropy, where the forces between the fibres are stronger and 469 mN for S3) than for MD (481 mN for S1, 496 mN for S2 and 418 mN for S3), which is to be expected for S2 and 469 mN for S3) than for MD (481 mN for S1, 496 mN for S2 and 418 mN for S3), which is to than the connections between the fibres. It is noticeable that the tensile strength S2 (496 mN in MD and 3.2.2 Tear strenght – Elmendorf The results of the tensile strength measurements for CD are in all cases higher (592 mN for S1, 606 mN 3.2.2 Tear strenght – Elmendorf paper is greater than S1 (481 mN in MD and 592 mN in CD). The difference is 2% (CD) and 3% (MD). From this rence is 2% (CD) and 3% (MD). From this we can conclude that the wood cellulose fibres in S2 606 mN in CD), i.e. of bagasse paper is greater than S1 (481 mN in MD and 592 mN in CD). The most likely originate from deciduous trees (Figure 3). we can conclude that the wood cellulose fibres in S2 most likely originate from deciduous trees (Figure 3). diffe rence is 2% (CD) and 3% (MD). From this we can conclude that the wood cellulose fibres in S2 most likely originate from deciduous trees (Figure 3). between the fibres. It is noticeable that the tensile strength S2 (496 mN in MD and 606 mN in CD), i.e. of bagasse 606 mN in CD), i.e. of bagasse paper is greater than S1 (481 mN in MD and 592 mN in CD). The than the connections between the fibres. It is noticeable that the tensile strength S2 (496 mN in MD and diffe to a certain extent, i.e. due to anisotropy, where the forces between the fibres are stronger than the connections be expected to a certain extent, i.e. due to anisotropy, where the forces between the fibres are stronger Figure 3: Tear strenght – Elmendorf 3.2.3 Figure 3: Tear strenght – Elmendorf Figure 3: Tear strenght – Elmendorf Sound velocity The sound velocity signal is faster in denser matter because there are more covalent bonds. In S1, the 3.2.3 Sound velocity 3.2.3 Sound velocity paper with the highest density of 713 kg/m3 (Table 1), the sound signal travelled at a speed of 3.37 km/s, The sound velocity signal is faster in denser matter because there are more covalent bonds. In S1, the the highest propagation speed of the sound signal among the three samples. The propagation of the paper with the highest density of 713 kg/m 3 (Table 1), the sound signal travelled at a speed of 3.37 km/s, sound pulse is faster in the direction of the fibres because the sound pulse propagates along the covalent The sound velocity signal is faster in denser matter because there are more covalent bonds. In S1, the paper the highest propagation speed of the sound signal among the three samples. The propagation of the bonds, which was also demonstrated in our measurements (Figure 4). The propagation speed of the with the highest density of 713 kg/m sound pulse is faster in the direction of the fibres because the sound pulse propagates along the covalent 3 (Table 1), the sound signal travelled at a speed of 3.37 km/s, the highest sound pulse in S2 is 2.77 km/s in MD and 1.78 km/s in CD. In S3, the propagation velocity of the sound propagation speed of the sound signal among the three samples. The propagation of the sound pulse is faster in bonds, which was also demonstrated in our measurements (Figure 4). The propagation speed of the the direction of the fibres because the sound pulse propagates along the covalent bonds, which was also demon sound pulse in S2 is 2.77 km/s in MD and 1.78 km/s in CD. In S3, the propagation velocity of the sound - 4 4 419 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia strated in our measurements (Figure 4). The propagation speed of the sound pulse in S2 is 2.77 km/s in MD and 1.78 km/s in CD. In S3, the propagation velocity of the sound pulse was 2.69 km/s in MD and 1.68 km/s in CD. The speed of the sound pulse is reflected in the degree of anisotropy and the degree of order of the molecular structure pulse was 2.69 km/s in MD and 1.68 km/s in CD. The speed of the sound pulse is reflected in the degree of the analysed causes of the papers. Annual plants have a lower degree of order in the macromolecular structure. of anisotropy and the degree of order of the molecular structure of the analysed causes of the papers. pulse was 2.69 km/s in MD and 1.68 km/s in CD. The speed of the sound pulse is reflected in the degree Annual plants have a lower degree of order in the macromolecular structure. of anisotropy and the degree of order of the molecular structure of the analysed causes of the papers. Annual plants have a lower degree of order in the macromolecular structure. Figure 4: Sound velocity and density of paper bags Figure 4: Sound velocity and density of paper bags Figure 4: Sound velocity and density of paper bags The S3 samples were obtained from bags that had already been manufactured, which meant that they were The S3 samples were obtained from bags that had already been manufactured, which meant that they were grooved to a certain length. In order for the causes to be comparable, they should not have been The S3 samples were obtained from bags that had already been manufactured, which meant that they grooved to a certain length. In order for the causes to be comparable, they should not have been mechanically mechanically damaged beforehand. For this reason, we used were grooved to a certain length. In order for the causes to be comparable, they should not have been a clamping length of 100 mm when damaged beforehand. For this reason, we used a clamping length of 100 mm when measuring the physical and measuring the physical and mechanical properties. The breaking force in [N] (Figure 5a), the elongation mechanically damaged beforehand. For this reason, we used a clamping length of 100 mm when mechanical properties. The breaking force in [N] (Figure 5a), the elongation at break in [%] (Figure 5b), the tensile at break in [%] (Figure 5b), the tensile strenght energy in [J] (Figure 5c) and the modulus of elasticity in 3.2.4 3.2.4 module Breaking strenght, elongation at break, tensile strenght energy and Young's Breaking strenght, elongation at break, tensile strenght energy and Young‘s module module 3.2.4 Breaking strenght, elongation at break, tensile strenght energy and Young's strenght energy in [J] (Figure 5c) and the modulus of elasticity in [GPa] (Figure 5d) were measured for selected measuring the physical and mechanical properties. The breaking force in [N] (Figure 5a), the elongation [GPa] (Fi at break in [%] (Figure 5b), the tensile strenght energy in [J] (Figure 5c) and the modulus of elasticity in gure 5d) were measured for selected paper bags that were clamped vertically between the paper bags that were clamped vertically between the clamps of the dynamometer at a speed of 0.25 mm/s. The clamps of the dynamometer at a speed of 0.25 mm/s. The results are shown in Figure 5. The breaking [GPa] (Fi gure 5d) were measured for selected paper bags that were clamped vertically between the results are shown in Figure 5. The breaking force of S1 in MD was 108.92 N (Figure 5a), the highest measured force of S1 in MD was 108.92 N (Figure 5a), the highest measured forc clamps of the dynamometer at a speed of 0.25 mm/s. The results are shown in Figure 5. The breaking e among all paper samples force among all paper samples tested, which is due to the content of primary wood cellulose fibres, i.e. fibres from tested, which is due to the content of primary wood cellulose fibres, i.e. fibres from coniferous trees. force of S1 in MD was 108.92 N (Figure 5a), the highest measured forc e among all paper samples coniferous trees. tested, which is due to the content of primary wood cellulose fibres, i.e. fibres from coniferous trees. a b a b c d Figure 5: Physical-mechanical properties; a) breaking strenght, b) elongation at break, c) Tensile c d Figure 5: Physical-mechanical properties; a) breaking strenght, b) elongation at break, c) Tensile strenght energy and d) Young's module Figure 5: Physical-mechanical properties; a) breaking strenght, b) elongation at break, c) Tensile strenght energy and d) strenght energy and d) Young's module Since paper is a viscoelastic material in which cellulose is present in crystalline and amorphous form, Young‘s module physical-mechanical loads initially lead to elastic deformation, which depends on the load time. As the Since paper is a viscoelastic material in which cellulose is present in crystalline and amorphous form, load increases, it then passes through the viscoelastic range up to plastic or irreversible deformation. physical-mechanical loads initially lead to elastic deformation, which depends on the load time. As the load increases, it then passes through the viscoelastic range up to plastic or irreversible deformation. 5420 5 29–30 May 2025, Ljubljana, Slovenia Since paper is a viscoelastic material in which cellulose is present in crystalline and amorphous form, physical-me-chanical loads initially lead to elastic deformation, which depends on the load time. As the load increases, it then passes through the viscoelastic range up to plastic or irreversible deformation. Figure 5b shows a comparison of the strains between the paper bag samples analysed. The elongation at break in MD for S1 and S2 is 1.95% for S1 and 1.96% for S2, while the elongation at break of S3 was half that of S1 and S2, namely 0.94%. For CD, the elongation at break is highest for S1, 4.9%, which means that the 10 cm long test piece was stretched by almost half a centimetre until it broke. High extensibility of paper sacks is a required property of the product, which must ensure adaptability to the contents of the sack. This was also measured by the tensile strength energy, Figure 5c, where the value is most influenced by the raw material composition of the paper for paper sacks, as it is a direct indicator of the extent of bonding between the fibres. Therefore, we also measured the modulus of elasticity, which tells us what stress is required for a given elongation. As we can see from Figure 5d, the highest modulus of elasti-city at S1 in MD is 4.34 GPa. This means that the paper S1 can withstand the maximum load in the corresponding direction without being permanently deformed. This is desirable for all printing papers, but especially for paper bag papers, where the main purpose is to stress the paper without physical-mechanical consequences. 1. CONCLUSIONS The length of the fibres has a direct influence on the physical-mechanical properties of the paper. From the cellulo-se fibres of coniferous trees, which are obtained using the sulphate process, we obtain a high-quality raw material with long fibres that enable good bonding between the fibres in the paper sheet and greater resistance to physical and mechanical stresses. The measurement results show that the paper made exclusively from kraft pulp (S1) is stronger in terms of physical and mechanical properties than the two papers made from the fibres of the annual plants included in the study. Paper with fibres made partly from grass and partly from wood pulp (S2) was even physically and mechanically stronger than paper made from secondary fibres and fibres from fallen leaves (S3). This shows that the wood fibres obtained by the sulphate process are a valuable raw material that improves the physical and mechanical properties of the paper. The search for alternative sources of cellulose fibres is to be welcomed from the point of view of lower energy consumption, the use of plant parts that would otherwise have to be destroyed, the shortening of transport routes and the reduction of water consumption. We believe that, at least in Slovenia, it would make more ecological sense to use wood that is sufficient for the paper industry if the forest is well managed. Since the length of the fibres also has a significant influence on the quality of the secon-dary fibre, it is important that the primary cellulose enters the paper manufacturing process with fibres that are as long as possible. If we consider the entire product life cycle of paper sacks made from kraft pulp and sacks made from the fibres of annual plants, we have to weigh up whether a paper sack with better physical-mechanical properties, i.e. a lower probability of tearing during use and a greater chance of being used more than once, has a greater impact on the environment. An important aspect of actual use is also the price, as paper made from the fibres of annual plants has a higher price than paper made from the cellulose fibres of trees. Another important aspect of carrier bags is their size. Large carrier bags, like the ones we see in grocery shops, have to carry loads of several kilogrammes and be made of paper that can withstand physical and mechanical stress. Small bags in clothing shops, jewellery shops, paper shops etc., where they are unlikely to have to carry a large mass, can be made of less physically and mechanically resistant paper. For further research, it would be interesting to find out what types of bags consumers would prefer. In terms of the composition of the paper, we could investigate what proportion of wood cellulose fibres and fibres from annual plants should be used so that the paper retains com-parable physical and mechanical properties. We could also experiment with replacing the fibres from deciduous trees in the kraft paper with fibres from annual plants, as the fibres are of comparable length. Paper bags made from cellulose fibres from annual plants are a welcome addition to the market for paper products, but at least for now they cannot completely replace bags made from cellulose fibres from trees. 421 29–30 May 2025, Ljubljana, Slovenia 2. REFERENCES Ainun, Z. M., Sapuan, S. M. and Ilyas, R. A. 2023. Pulping and Papermaking of Nonwood Plant Fibres. Amsterdam: Academic Press, Elsevier. Bajpai, P. 2021. Nonwood Plant Fibres for Pulp and Paper. Amsterdam; Oxford; Cambridge: Elsevier. Gregor Svetec, D. Franken, G. and Možina, K. 2020. Papir in grafični izdelki iz invazivk. URL: http://www.dlib.si/details/URN:NBN:SI:DOC-KTEVT89R/ (last accessed on 6. 2. 2025). Možina, K. 2017. ”Viscoelastic properties of graphic papers.” PhD diss. University of Ljubljana. Tomšič, A. 2020. ”Lastnosti papirja, narejenega iz slame.” Diploma thess. University of Ljubljana. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author: Klemen Možina Ana Štrucelj and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška 5 Snežniška 5 1000, Ljubljana, Slovenija 1000, Ljubljana, Slovenija Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana schweiger.ana@gmail.com 00386 1 200 32 99 klemen.mozina@ntf.uni-lj.si 422 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION IMPACTS OF PRINTED INTELLIGENT ELEMENTS ON CARDBOARD PACKAGING RECYCLABILITY: METHOD EVALUATION AND FINDINGS Patricija Pevec1,2, Tea Kapun1 and Diana Gregor Svetec2 1 Pulp and Paper Institute, Slovenia 2 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: This study examines the recyclability of intelligent cardboard packaging, specifically evaluating the im-pact of printed RFID antennas and thermochromic indicators on recycling outcomes. Three recycling assessment methods were reviewed: the CEPI Recyclability Test Method (version 2), ATICELCA Method, and Eco Paper Loop Method, each offering unique approaches to evaluating fiber recovery, contaminant management, and life-cycle sustainability. The CEPI method was selected to perform the recyclability test on cardboard packaging due to its emphasis on fiber yield, pulp quality, and contaminant separation, aligning with EU recycling mill conditions. Using this method, recycling trials were conducted on two types of cardboard packaging: unprinted cardboard and cardboard with integrated printed intelligent elements. Results revealed a high recyclability score for both samples, with recycling efficiency exceeding 99 %, confirming minimal impact from functional conductive and thermochromic inks on recyclability and the optical properties of hand sheets. Keywords: recycling, intelligent packaging, cardboard, RFID antenna, thermochromic indicator. 1. INTRODUCTION The increasing consumption of paper products worldwide has amplified the need for efficient and sustainable recycling systems. Paper recycling not only reduces resource depletion and energy consumption but also mini-mizes environmental pollution, making it a key pillar of the circular economy. (Defalque, et al., 2021) (Kowalska, et al., 2021) Everyone participating in the paper value chain must be careful, that their actions do not harm the whole chain. Packaging of today must go beyond utility. For the paper value chain, the basic knowledge about the recyclable’s lifecycle is not yet sufficient. (Kochersperger, et al., 2024) Sustainable product design emphasizes the use of recycled materials while striving to ensure that all components remain recyclable. (Nordin, et al., 2010) To address the challenges of recycling diverse paper products, several methodologies have been developed, including CEPI (Confederation of European Paper Industries), Eco Paper Loop, and Aticelca. These systems aim to evaluate and optimize recyclability, focusing on quality control, contamination reduction, and the promotion of eco-design principles. Few studies have explored the recyclability of intelligent cardboard packaging. During the recycling process of paper and cardboard, intelligent components like RFID tags and thermochromic indicators remain attached to the packaging and enter the process without prior separation. As the use of intelligent packa-ging grows, concerns arise regarding its impact on recyclability. However, research on the recycling performance of printed RFID antennas and thermochromic indicators in fiber-based packaging remains limited. (Pevec et al., 2025) Vukoje et. al. showed that irreversible thermochromic inks are difficult to remove through standard deinking flotation. Flotation can reduce paper opacity by removing fillers and possibly optical brighteners but is not ideal for recycling materials like thermochromic indicators. They suggested exploring other methods. (Vukoje et al., 2021) 1.1 Comparison of recyclability test methods CEPI test method is the relevant test method to be used for standard mills. It defines a laboratory procedure with the most relevant process stages (pulping, coarse and fine screening, sheet formation), while the cleaning step is not included due to a lack of suitable equipment widely available in most EU labs. The test method provides results relevant to the process efficiency (yield, coarse and fine reject amount) as well as to the recycled paper quality (visual impurities and sheet adhesion). CEPI‘s approach emphasizes standardizing recycling evaluation 423 29–30 May 2025, Ljubljana, Slovenia across Europe to ensure consistency in results. (CEPI, 2022) By focusing on adhesive stickiness and deinka-bility, CEPI test method targets two of the most significant challenges in paper recycling, particularly for printed products. These test methods aim to enhance the quality of recycled fibers, reduce operational inefficiencies, and promote environmentally friendly practices within the paper industry. (Defalque, et al., 2021) (Lumme, 2022) For instance, CEPI has worked on a pan-European standardization of the PTS method, which tests adhesion levels and surface changes caused by adhesives during recycling processes. (Lumme, 2022) The Eco Paper Loop initiative focuses on improving the recyclability of paper-based packaging by evaluating con-tamination levels, optimizing fiber recovery rates, and recommending best practices for paper collection systems. By integrating recyclability into the product design stage, this initiative not only enhances resource efficiency but also encourages circular economy practices across the European paper industry. (EcoPaperLoop, 2014) (Kow-alska, et al., 2021) The project’s guidelines, including EcoPaperLoop Method 1 for packaging recyclability, serve as benchmarks for manufacturers aiming to reduce non-paper components and improve recyclability. (EcoPaper-Loop, 2014) (Kowalska, et al., 2021) Aticelca, through its Evaluation System 501:2019, provides a structured framework for classifying paper products based on their recyclability. Rooted in the UNI 11743:2019 standard, this system assigns recyclability grades (A+, A, B, or C) by evaluating process parameters such as adhesive particle size and product quality after recycling. Its primary goal is to encourage manufacturers to adopt eco-design principles and ensure the efficient reprocessing of cellulosic materials. (Aticelca, 2019) The Aticelca system not only fosters collaboration among stakeholders but also highlights the importance of integrating recyclability considerations into product development. (Aticelca, 2019) (Lumme, 2022) Table 1: Comparison of the recyclability test methods. ATICELCA test meth- CEPI test method, EcoPaperLoop test od Version 2 method Disintegration 10 min 10 min 5 min 3000 revolutions/min, 3000 revolutions/min, 40°C, 4% stock consis-40°C, 2.5% stock con-40°C, 2,5% stock con-tency sistency sistency Soluble and colloidal Filtrate analysis and Filtrate analysis and / substances COD* (optional) COD (optional) Coarse reject (coarse Brecht-Holl screening Somerville fractionator Somerville fractionator screening) device 50 g of OD** material, 50 g of OD material, 10 g of OD material, 5 min, 5 mm holes 5 min, 5 mm holes 5 min, 10 mm holes Fine reject Somerville fractionator Somerville fractionator Haindl classifier (fine screening) 5 g of OD material, 20 g of OD material, 20 10 g of OD material, 5 min, 0,15 mm slots min, 0,15 mm slots 5 min, 0,7 mm holes Sheet adhesion (tacki-Adhesion test after fine Adhesion test after co- Adhesion test after fine ness) screening arse and fine screening screening MSA*** MSA (optional) MSA Visual impurities Visual impurities after Visual impurities after Visual impurities after coarse and fine scre-fine screening fine screening ening *COD = Chemical Oxygen Demand **OD = Oven Dry ***MSA = Macrostickies analysis 424 29–30 May 2025, Ljubljana, Slovenia These methodologies collectively address critical challenges in modern paper recycling, including contamination from adhesives, the need for standardization, and the integration of eco-design principles. By combining the strengths of these systems, the paper industry is advancing toward a sustainable future while aligning with global environmental goals. (Defalque, et al., 2021) (EcoPaperLoop, 2014) (Kowalska, et al., 2021) 2. EXPERIMENTAL The goal of the study was to select one laboratory test method to perform recyclability test, conduct recycling according to that method, and evaluate recyclability. Due to the increasing presence of smart packaging, a re-cyclability assessment was performed on the cardboard with the integrated printed intelligent elements as an example of smart cardboard packaging. In practical part of the research, our focus was on the assessment of two elements of intelligent packaging, RFID tag and thermochromic indicator. For the recycling of cardboard packag-ing the CEPI method was applied. This method was used to assess recyclability by dissolving the samples and determining the coarse reject through a coarse screening process. The concentration after the coarse and fine screening was determined and from obtained recycled fibres the hand sheets were produced on which the adhe-siveness test and visual assessment were carried out. 2.1 Materials and method 2.1.1 Materials The selected base material for smart packaging was coated cardboard, with a grammage of 350 g/m². Cardboard packaging was made with application of starch adhesive. To obtain smart packaging, a screen-printing technique was employed to integrate both the RFID antenna and the thermochromic indicator onto the cardboard. For the RFID antenna, the metallic functional ink CRSN2442 SunTronic Silver 280 was used. For printing thermochromic indicator the Chromatic Technologies (CTI) thermocromic UV Screen Ink, changing color at 30 ◦C, was used. The ink contains leuco dyes, which exist in either a colored or colorless state, depending on temperature. This ink undergoes reversible structural changes when heat disrupts their molecular interactions. When heated abo-ve 30°C, interactions between the leuco dye and developer are disrupted, causing the ink to become colorless. Unlike conventional thermochromic coatings that rely on liquid solvents, this ink hardens under UV light, making it more durable and suitable for high-performance printing applications. The recyclability test was performed on cardboard packaging (CP) and smart cardboard packaging (ICP). 2.1.2 Methods In the experimental part of the research, we tested the recyclability of two different samples according to the CEPI Recyclability Laboratory Test Method, Version 2, October 2022. To conduct the recycling tests, 50 g of oven-dry material was prepared for disintegration, with each sample cut into 3 cm x 3 cm pieces. Disintegration was performed for 10 minutes using conditions reported in Table 1. The entire sample suspension was utilized for coarse screening, starting with 50 g of oven-dry material. After the coarse screening process, presented in Table 1, material retained on the perforated plate was collected and filtered in a Büchner funnel. The coarse reject was then dried using a Rapid-Köthen dryer at 93°C for 10 minutes, followed by oven drying at 105°C until a constant mass was achieved. The suspension consistency was determined by standard ISO 4119 to produce 60 ± 2 g/m² laboratory sheets using a Rapid-Köthen sheet former for adhesion evaluation after coarse screening. Additionally, 20 g of oven-dry material underwent fine screening. For adhesion testing, the laboratory sheet was layered with a carrier board and cover sheet, dried, and heated at 130°C for 2 minutes. After cooling, it was examined under direct and tran-smitted light for impurities. Fine screening used a Somerville screen under conditions given in Table 1, with reta-ined material processed as fine reject and analyzed similarly to coarse screening. Finally, the recyclability score was calculated using the coarse reject, fine reject, visual impurities, and sheet adhesion data derived from the accept material after fine screening. 425 29–30 May 2025, Ljubljana, Slovenia The optical properties of hand sheet were determined using standards. A total of 10 measurements were conduc-ted per sample. For measuring ISO brightness SIST ISO 2470–1:2017 was applied. The opacity was determined by SIST ISO 2471:2011. Color measurements were performed in the CIE Lab* color space, a standard defined by the International Commission on Illumination. This system characterizes color using three coordinates: L*, which indicates brightness on a scale from 0 (black) to 100 (white); a*, which represents the position on the red-green axis; and b*, which indicates the position on the yellow-blue axis. 3. RESULTS AND DISCUSSION Two samples were compared, the simple cardboard packaging (unprinted cardboard with water soluble glue), marked as CP, and the same packaging, equipped with the printed RFID antenna and thermochromic indicator, marked as ICP. In Table 2 results obtained after performing recyclability test are presented. Figure 1: The image shows an example of a sample intelligent cardboard packaging (ICP) from the front and back. After the coarse screening process, almost no rejects remained on the perforated plate, which aligned with our expectations. Similar to the findings of Aliaga et al. (Aliaga, et al., 2011), we assumed that the printed electronics from the RFID tag would be retained by the sieve, with only a minimal amount making its way into the screened fibers. The calculated percentage of coarse rejects ranged from 0.03% to 0.11%, consisting mainly of small fiber flakes and residual printing ink that became trapped in the gaps between the 5 mm holes after the dewatering process in Somerville. Table 2: Results of recyclability testing: coarse reject, fine reject, yield, visual impurities after fine screening, sheet adhesion after fine screening and recyclability score for both samples: cardboard packaging (CP) and intelligent cardboard packaging (ICP). Coarse reject Fine reject Yield Visual impuri- Sheet adhe- Recyclability ties after fine sion after fine score (%) (%) (%) screening screening (/) (Level) (Level) CP 0.03 0.11 99.9 1 1 100/100 ICP 0.05 0.15 99.8 3 1 85/100 Following fine screening, a higher percentage of rejects was anticipated due to the smaller screen plate openings, which allow the passage of good material while capturing more impurities. The fine reject calculations varied between 0.08% and 0.55%. The first sample left almost no visible rejects on the plate, apart from a few minor fiber flakes. However, in the sample containing the thermochromic indicator, numerous small particles of thermochromic ink were retained on the plate. The functional ink of the RFID antenna was not visible to the naked eye on the plate, yet small dots were observed within the screened material. The hand sheets likely contained minimal amount of adhesive, as there was no noticeable tackiness. The level 426 29–30 May 2025, Ljubljana, Slovenia of sheet adhesion in both samples was rated as 1, meaning no adhesion issues were detected when processing the recovered material. In the second sample, small dots were also visible on the hand sheet, as previously men-tioned in relation to the residues found on the perforated plate, confirming the presence of functional ink. These small impurities were only noticeable upon close examination of the hand sheet and had no significant impact on its optical properties. Consistent with the conclusions of Aliaga et al. (Aliaga, et al., 2011), we found that variations in visual properties were minor and did not interfere with the sample recycling procedures. The consistency of results after fine screening was affected the least by these factors. Figure 2: The image of hand sheets after fine screening of samples, photographed using transmitted light. Table 3: Optical properties of hand sheets produced after fine screening, given as average value and standard deviation. L* a* b* ISO brightness Opacity (/) (/) (/) [%] [%] CP 96.4±0,04 3.24±0,03 -11.4±0.12 107±0.20 85.9±0.10 ICP 96.5±0,04 3.19±0,02 -11.5±0.07 108±0.19 85.7±0.05 As seen in Table 3, the difference in optical properties between both samples is so minor that it can be conside-red negligible. Anyway, we can see, that ISO brightness is higher than 100 scale. It means, that our cardboard is treated with optical brightening agents (OBAs) or other chemical additives, which enhance their ability to reflect light, particularly under UV light. As a result, these treatments can cause the paper’s ISO brightness to exceed the standard 100 scale. 4. CONCLUSIONS Our research demonstrated that while thermochromic ink and functional conductive ink had slightly higher levels of fine rejects and minor visual impurities compared to the CP sample, these did not significantly impact the ma-terial’s recyclability or optical properties. Both tested samples exhibited excellent sheet adhesion, their visual and optical properties remained comparable after the fine screening process and were deemed suitable for standard recycling processes, achieving top-tier performance with recycling efficiencies exceeding 99% and recyclability scores ranging from 85 to 100%. The minor differences in recyclability scores (100/100 for CP and 85/100 for ICP) indicate that the addition of printed electronics and functional inks does not severely hinder the recycling process. These findings confirmed our initial hypothesis: packaging containing printed RFID antennas and thermochromic indicators maintains high recyclability with negligible effects on the recycling process. 427 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES: Aliaga, C., Ferreira, B., Hortal, M., Pancorbo, M., López, J., & Navas. “Influence of RFID tags on recyclability of plastic packaging.” Waste management Volume 31, Issue 6: pp. 1133-1138. Lumme, E., 2022. “Tahmatestausmenetelmän validointi.” Metropolia Ammattikorkeakoulu. Aticelca, 2019, Evaluation System 501:2019 – Assessment of the lever of recyclability of materials and products predominantly cellulosic on the basis of the UNI 11743:2019 standard, Milan. CEPI, 2022b, Cepi recyclability laboratory test method – Harmonised European laboratory test method to generate parameters enabling the assessment of the recyclability of paper and board products in standard paper and board recycling mills, CEPI, Brussels. Defalque, C., Marins, F., da Silva, A., & Rodríguez, E., 2020. “A review of waste paper recycling networks focusing on quantitative methods and sustainability” Journal of Material Cycles and Waste Management Volume 23: pp 55–76. EcoPaperLoop, 2014. Enhancing the Quality of Paper for Recycling in Europe: Optimising Paper Products, Packaging and Collection Systems: Outcome – Guidelines and Recommendations, European Union/European Fund for Regional Development, Brussels. Kochersperger, S., & Schabel, S., 2024. “Recyclability of Paper₂Based Composites for Packaging Applications – The Role of Evaluation Methods” Chemie Ingenieur Technik Volume 96, Issue 7: pp. 891-901. Kowalska, M.A., Donatello, S. and Wolf, O., 2021. “EU Ecolabel Criteria for printed paper, stationery paper, and paper carrier bag products.” Publications Office of the European Union, Luxembourg. Nordin, N., & Selke, S., 2010. “Social aspect of sustainable packaging.” Packaging Technology and Science Volume 23, Issue 6: pp. 317-326. Pevec, P., Kapun, T. & Gregor-Svetec, D. 2025. “Recyclability of Intelligent Cardboard Packaging” Sustainability Volume 17, Issue 7: pp 2924. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Patricija Pevec Tea Kapun Bogišićeva 8 Bogišićeva 8 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia Pulp and Paper Institute, Ljubljana Pulp and Paper Institute, Ljubljana patricija.pevec@icp-lj.si tea.kapun@icp-lj.si Diana Gregor Svetec University of Ljubljana Faculty of Natural Sciences and Engineering Snežniška ulica 5 1000 Ljubljana, Slovenia diana.gregor@ntf.uni-lj.si 428 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION SUSTAINABLE GIFT PACKAGING: DESIGN GUIDELINES BASED ON ECO-DESIGN PRINCIPLES Andreja Pogačar1 and Diana Gregor-Svetec2 1Dodopack, d.o.o., Slovenia 2Faculty of Natural Sciences and Engineering, Slovenia Abstract: Sustainable eco-design aims to minimize environmental impacts across a product’s entire life cycle, from design and production to use and disposal. This study develops guidelines for sustainable gift packaging, emphasizing multifunctionality, interactivity, and recyclability. The research includes a case study of Tr’glav pack-aging, part of Bled Local Selection, which integrates Slovenian cultural elements with sustainable and smart packaging design. Packaging from corrugated cardboard without print and paper label are identified as the op-timal packaging materials due to their high recyclability. Interactive elements, such as QR codes, RFID tag and augmented reality enhance user engagement while maintaining recyclability of packaging. Additionally, the pack-aging incorporates reuse strategies, such as transformation into a bee habitat. The findings provide guidelines for designers developing sustainable, interactive packaging aligned with eco-design principles. Keywords: eco-design, guidelines, gift packaging, multifunctionality, interactive packaging 1. INTRODUCTION Sustainable eco-design aims to minimize the environmental impact of products throughout their entire life cycle, from design and production, to use and disposal. Key strategies in eco-design focus on reducing energy and ma-terial consumption, reusing components, upgrading products, and recycling materials, including waste generated during production, while also considering energy recovery (Brezet, 1997). However, the accumulation of waste is often a result of poor management and design decisions, highlighting the need for more effective sustainable strategies (Urukalo, 2010). In the context of packaging, sustainable design prioritizes waste elimination, material reduction, and the reuse or recycling of packaging at the end of its life cycle, returning materials as raw inputs for further production (Azzi et al., 2012). Sustainable packaging not only protects products but also serves as a marketing and communication tool, sha-ping consumer perception and adding value (Snoj, 1981; Dreyfuss, 2003; Pisnik Korda & Snoj, 2006; Yam, 2010). Fundamental concepts in sustainable packaging design include recyclability, multifunctionality, and material effi-ciency (Kozik, 2020; Radonjič, 2014). At the same time, advancements in smart packaging enable features such as tracking and consumer engagement via QR codes, RFID tags, and augmented reality (AR) (Realini & Marcos, 2014; Restuccia et al., 2010). However, studies suggest that these interactive elements are underutilized unless consumers are specifically encouraged to engage with them (Žurbi & Gregor-Svetec, 2023). Despite progress in sustainable packaging, the industry faces several challenges, including inefficient waste ma-nagement, excessive material use, and suboptimal packaging design. Over-decoration and excessive packaging remain prevalent, leading to increased waste production and higher costs (Liu & Wang, 2023). While consumer demand for minimalist and eco-friendly packaging is growing, a lack of clear sustainability information often pre-vents informed purchasing decisions (Future Market Insights, 2021; Steenis et al., 2017). Regulatory frameworks, such as the European Union Directive 94/62/EC, aim to address these issues by promoting recycling and material reuse. Although the EU has achieved a municipal waste recycling rate of 48% in 2022, challenges persist in sor-ting and reprocessing complex packaging materials (Statista, 2025). This study focuses on developing guidelines for sustainable gift packaging that emphasize multifunctionality, in-teractivity, and recyclability. The research explores innovative design strategies that extend packaging lifespans through reuse while integrating interactive elements to enhance user experience and reduce the reliance on prin- 429 29–30 May 2025, Ljubljana, Slovenia ted materials. Additionally, it highlights the importance of corrugated cardboard as a widely used and recyclable material, offering an optimal balance between sustainability and mechanical performance (González-García et al., 2016). By adopting a mixed-method research approach—including literature reviews, case studies, and user research— this study examines a case of sustainable gift packaging developed for the Tr’glav brand, part of the Bled Local Selection initiative (Pogačar, 2023). This case integrates elements of traditional Slovenian culture with modern sustainability and smart packaging technologies, providing valuable insights into the future of eco-friendly and interactive gift packaging. 2. EXPERIMENTAL The study described in the doctoral dissertation Design Guidelines for Interactive Sustainable Gift Packaging employed a structured experimental approach to evaluate the sustainability, functionality, and user perception of the Tr’glav gift packaging. The research combined laboratory material testing, interactive technology integration, and user-centred studies to assess packaging performance. The research methods applied are described in detail in the doctoral dissertation (Pogačar, 2023). 2.1 Material Selection Materials were selected based on mechanical properties and performance, with consideration for sustainability. The tested materials included corrugated cardboard of various thicknesses and composition, and self-adhesive paper labels of different composition (Pogačar, 2023). Physical tests of corrugated cardboard included measurements of grammage, thickness, and moisture absorption, while mechanical assessments examined tensile strength, bending stiffness, puncture resistance, tear resistance, ECT and FCT. Additionally, durability tests on printed labels assessed resistance to light, moist-heat treatment, and abrasion. These analyses ensured the selection of materials that balance sustainability with durability and functionality. 2.2 Integration and Evaluation of Interactive Technologies To assess the impact of interactive technologies on user experience and recyclability, the Tr’glav packaging prototypes incorporated QR codes, RFID tags, and AR features. QR codes provided digital product and sustainability information, RFID tags facilitated tracking and logistical optimization, while AR enabled interactive experiences through mobile applications. User interaction studies were conducted to evaluate accessibility, usability, and consumer engagement with these technologies (Pogačar, 2023). Additionally, recyclability impact assessments examined whether interactive elements influenced material recovery processes (Pogačar, 2023). The results provided insights into the feasibility of integrating interactive technologies without compromising packaging sustainability. 2.3 User Research and Consumer Perception Analysis A combination of quantitative and qualitative methods was used to assess consumer attitudes towards sustainable and interactive packaging (Pogačar, 2023). An online survey was distributed to a diverse Slovenian audience, employing a Likert scale to evaluate sustainability, functionality, and technological features. A total of 207 valid responses were collected and analysed. In addition to the survey, focus groups provided deeper insights into user experience. Two key groups participated: employees from Turizem Bled, who evaluated the packaging’s suitability for the tourism industry, and members of Katapult business incubator, who analysed its innovative and commercial potential. Participants engaged directly with the packaging, assessing its visual appeal, ease of use, label clarity, and overall perception of sustainability. 430 29–30 May 2025, Ljubljana, Slovenia 2.4 Field Testing and Real-World Validation To validate the functional performance and market acceptance of the packaging, real-world field tests were conducted. These trials involved retail environment placements to observe consumer interactions, analysis of handling and durability during transportation, and user behaviour tracking to assess engagement with interactive elements (Pogačar, 2023). Additionally, reuse potential and multifunctionality were evaluated to determine whether consumers repurposed the packaging beyond its initial function. 3. RESULTS WITH DISCUSSION The collected data from laboratory testing, interactive technology assessments, user experience studies, and field trials were systematically analysed to establish correlations between material properties, digital engagement, and user satisfaction. The findings provided empirical evidence for developing guidelines on sustainable, multifunctional, and interactive packaging solutions. The results of the study demonstrate that sustainable interactive gift packaging can be effectively developed through a strategic combination of environmentally friendly materials, functional structural design, and interactive elements. The integration of these components supports the principles of circular economy, reduces environmental impact, and enhances user engagement (Pogačar, 2019). The findings highlight key material choices, design strategies, and consumer preferences, offering practical guidelines for sustainable packaging development (Pogačar, 2023). 3.1 Material Selection and Performance Corrugated cardboard is a sustainable packaging material due to its high recyclability, biodegradability, and minimal environmental footprint. However, recycled corrugated cardboard exhibited slightly reduced mechanical strength and limited moisture resistance; nevertheless, its strength and performance were suitable for the selected packaging design (Pogačar, 2023; Pogačar & Gregor-Svetec, 2024). The study also examined labelling solutions, confirming that a self-adhesive label made from FSC-certified paper with biodegradable adhesive exhibited good print durability and recyclability, making it the most sustainable option (Pogačar et al, 2024). Packaging elements that include plasticized layers or foil coatings were found to hinder recyclability. Therefore, the research strongly recommends adopting a monomaterial approach, ensuring that all components are easily separable and recyclable. 3.2 Structural Design and Functionality The structural design of the packaging plays a critical role in ensuring durability, multifunctionality, and ease of transport. The results revealed that consumers highly value packaging that can be repurposed or reused after its initial function. A modular system was identified as an effective solution, allowing users to reassemble different parts of the packaging, thereby extending its lifespan (Pogačar & Gregor-Svetec, 2024). Tests demonstrated that integrated handles and foldable closure mechanisms enhance functionality while reducing the need for additional packaging materials such as gift bags. Furthermore, compact and stackable packaging designs contribute to transport efficiency and material optimization. The study supports a minimalist approach, where excessive decorative elements and unnecessary material usage are eliminated to improve sustainability (Pogačar, 2023; Pogačar & Gregor-Svetec, 2024). The mechanical durability tests showed that optimizing the structure of corrugated cardboard—by strategically placed folds—significantly enhances resistance to pressure and impact without increasing material consumption. This finding is particularly relevant for ensuring protective functionality while minimizing waste (Pogačar, 2023). 3.3 Impact of Digital and Interactive Elements The research assessed the feasibility of integrating interactive smart elements within sustainable packaging, focusing on RFID tags, QR codes, and AR. The findings indicate that these features do not compromise recyclability and, in some cases, reduce printed material consumption by shifting product information to digital formats (Pogačar, 2023; Pogačar et al., 2024). 431 29–30 May 2025, Ljubljana, Slovenia Among the interactive elements, QR codes proved to be the most effective in delivering digital product details, recycling instructions, and promotional content. Printed RFID tags offer advantages in supply chain tracking and inventory management, with no significant impact on recyclability (Pogačar et al., 2024). AR features were found to increase consumer engagement, particularly among younger demographics. However, their effectiveness depends on consumer familiarity with digital applications. The results suggest that AR integration is most beneficial for brands targeting digitally inclined audiences (Pogačar, 2023). 3.4 Sustainability Beyond Disposal A key objective of sustainable packaging is to extend its lifecycle beyond single-use functionality. The study identified an innovative secondary-use concept, where the packaging can be repurposed into a solitary bee nesting habitat (Pogačar, 2023). This approach adds environmental value by encouraging biodiversity and aligns with the principles of circular economy and zero-waste design (Pogačar, 2019). The findings suggest that packaging should incorporate practical reuse possibilities to increase its appeal and functional longevity. Implementing design-for-reuse principles ensures that packaging does not become waste but serves an extended purpose, reinforcing sustainable consumer behaviour (Pogačar & Gregor-Svetec, 2024). 3.5 Consumer Perception and Market Preferences Consumer feedback collected through surveys and focus groups confirmed that aesthetic appeal, sustainability, and functionality are the most influential factors in packaging perception. Packaging that clearly communicates its environmental benefits received higher preference, reinforcing the need for eco-labelling and transparency in sustainability claims (Pogačar, 2023). The research found that minimalist design approaches resonate strongly with modern consumers, as excessive decorative elements often create the perception of overconsumption and unnecessary waste. Consumers were more likely to support packaging that visibly aligns with sustainability values while maintaining practical usability and an appealing visual identity (Pogačar, 2023). 4. CONCLUSIONS A well-balanced integration of eco-friendly materials with optimized design creates sustainable, functional pac-kaging that enhances consumer engagement. Corrugated cardboard, due to its recyclability and strength, rema-ins the most suitable material, with structural reinforcements further improving durability. Monomaterial designs without adhesives support circular economy principles, while structural modifications enhance usability and mini-mize material waste. Interactive technologies, particularly QR codes and AR, reduce printed materials and impro-ve consumer interaction, with RFID tags adding logistical benefits without compromising recyclability. Consumer preference for minimalist, clearly labelled, and eco-friendly packaging reinforces the importance of transparent sustainability communication. A holistic approach—combining sustainable materials, functional de-sign, and digital features—drives packaging innovation that meets environmental, functional, and consumer ex-pectations. 5. ACKNOWLEDGEMENT: This study was conducted as part of the research core fundings [Program P2-0213] 432 29–30 May 2025, Ljubljana, Slovenia 6. REFERENCES: Azzi, A, Battini, D, Persona, A. and Sgarbosa, F. 2012. “Packaging design: general framework and research agenda.” Packaging technology and science 25(8): 435-456. Brezet, H. 1997. “Dynamics in eco-design practice.” Industry and Environment, 20: 21-24. Dreyfuss, H., 2003. Designing for people. New York: Viking. Future market insights, 2021. Gift Packaging Market. URL: https://www.futuremarketinsights.com/reports/gift-packaging-market (last accessed on 25. 7. 2023). 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Pogačar, A. 2023. “Smernice za načrtovanje interaktivne trajnostne darilne embalaže” PH diss., University of Ljubljana. Pogačar, A., Bolanča Mirković, I and Gregor-Svetec, D. 2024. “Print durability and recyclability of label paper equipped with printed RFID antenna.” Sustainability 16(1): 1-16. Pogačar, A. and Gregor-Svetec, D. 2024. “Innovative multipurpose gift packaging.” In: Book of proceedings : 9th International Joint Conference on Environmental and Light Industry Technologies, edited by Csanák, V., 63-73. Budapest: Óbuda University, Sándor Rejtő Faculty of Light Industry and Environmental Engineering. Radonjič, G., 2014. Oblikovanje in razvoj okolju primernejše embalaže. Maribor: Fakulteta za kemijo in kemijsko tehnologijo. Realini, C.E. & Marcos, B., 2014. “Active and intelligent packaging systems for a modern society.” Meat science, 98(3), pp.404-419. Restuccia, D., Spizzirri, U.G., Parisi, O.I., Cirillo, G., Curcio, M., Iemma, F., Puoci, F., Vinci, G. & Picci, N., 2010. “New EU regulation aspects and global market of active and intelligent packaging for food industry applications.” Food control, 21(11), pp. 1425-1435. Snoj, B., 1981. Embalaža-sestavina politik izdelkov in komuniciranja v marketingu. Ljubljana: ČGP Delo. Statista, 2024. Recycling rate of municipal waste in the European Union (EU-27) in 2010 and 2022, by country. URL: https://www.statista. com/statistics/1219551/municipal-waste-recycling-eu-by-country/ (last accessed on 31. 1. 2025). Steenis, N.D., Van Herpen, E., Van der Lans, I.A., Ligthart, T.N. & Van Trijp, H.C., 2017. “Consumer response to packaging design: The role of packaging materials and graphics in sustainability perceptions and product evaluations.” Journal of cleaner production, 162, pp. 286-298. Urukalo, S. 2010. Odločitev za odgovornost: o oblikovalski etiki in oglaševanju. Marketing Magazin. Ljubljana: Društvo oblikovalcev Slovenije. Yam, K.L. ed., 2010. The Wiley encyclopedia of packaging technology. Hoboken: John Wiley & Sons Inc. Žurbi, T. & Gregor Svetec, D., 2023. “Use of QR Code in Dairy Sector in Slovenia.” SAGE Open, 13(2), pp. 1-16. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author: Department of Textiles Dodopack, d.o.o. Gabrsko 12 Graphic Arts and Design Diana Gregor-Svetec Andreja pogačar Faculty of Natural Sciences 1420 Trbovlje, Slovenia and Engineering, +386 40 571 217 andreja@dodopack.com University of Ljubljana Snežniška 5 1000 Ljubljana, Slovenia +386 1200 3272 diana.gregor@ntf.uni-lj.si 433 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION DESIGNING CARDBOARD PACKAGING FOR CERAMIC PRODUCT TRANSPORTATION AND BRAND IDENTITY DEVELOPMENT Sandra Grlj1 and Urška Vrabič-Brodnjak1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: This research develops an innovative, recyclable cardboard packaging solution for the safe transpor-tation of ceramic products while reinforcing brand identity. The design prioritizes sustainability, functionality, and aesthetic appeal, aligning with modern eco-friendly packaging trends. Corrugated cardboard was selected for its strength, lightweight nature, and high recyclability. The study explores packaging’s dual role in product protection and brand communication, integrating eco-design principles and sustainable materials. An experimental approach tested various prototypes, culminating in a refined design featuring a safety belt mechanism for enhanced transit stability. The final solution balances protection, sustainability, and visual appeal, contributing to the advancement of eco-friendly packaging for fragile products. Keywords: cardboard packaging, ceramic product, eco-design, branding. 1. INTRODUCTION Packaging is an integral part of our daily lives. Without design and information, packaging would make our ev-eryday routines less practical, less informative and far less appealing. It not only communicates what’s inside but also shapes our experience of the product (Gao et. al, 2021, Hi et. al., 2024). Design and information are tightly connected. Well-designed packaging improves the user experience and conveys a sense of quality (Nguyen et al., 2020). But in today’s world, good design alone is no longer enough. Despite well-designed packaging, large quantities of products still end up in landfill. This shows how important it is to choose sustainable materials and design packaging that minimises waste. For ceramic products, the packaging must provide adequate protection to ensure that the items remain intact (Sanchez-Belenguer et.al, 2015, Elkhattat & Medhat, 2022). From personal experience in the ceramic’s courses, the finished products are often wrapped in paper and put in a bag, which often leads to breakage during transport (Sundlof & Fasano, 2007). This challenge gave us the idea to develop a more effective and sustainable packaging solution. This research aimed to explore environmentally friendly and functional packaging solutions for fragile products, focusing on developing a protective yet simple design that is cost-effective and minimizes material use. Card-board was chosen as the primary material to create packaging that is easy to handle for transporting ceramics while also offering the potential for reuse as storage. A key objective was to analyse the market for fragile product packaging and develop a custom solution specifically for ceramic items. The design needed to balance aesthetics with sustainability, minimizing ink consumption while maintaining visual appeal. Additionally, a brand identity was created, guided by eco-design principles. The primary challenge was designing packaging that could accommodate the unique nature of handcrafted ce-ramics. Unlike mass-produced items, ceramics made in courses and workshops vary in shape and size, requiring a flexible packaging solution. Market research revealed that most existing packaging is designed for products with fixed dimensions. While many innovative box designs exist, very few offer adaptability. To address this gap, we developed a packaging solution consisting of an outer box that appears conventional but incorporates an internal structure with adjustable cardboard inserts. These inserts provide additional stability when needed, ensuring that ceramics remain secure during transport—from the place of production to their destination. 434 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia The final packaging design is a corrugated cardboard box, suitable for most ceramic course projects. It features a handle for easy carrying and an innovative fastening system that allows the box to be attached to a car seatbelt or bicycle basket to increase stability during transport. 2. EXPERIMENTAL 2. EXPERIMENTAL 2.1 Materials 2.1 Materials The cardboard we used for the packaging was E-wave, uncoated, white cardboard, with a thickness of 1.5 mm The cardboard we used for the packaging was E-wave, uncoated, white cardboard , with a thickness of and grammage 320 g/m 2 . Before the box was assembled it was laminated with a vinyl sticker on which the brand 1.5 mm and grammage 320 g/m 2 . Before the box was assembled it was laminated with a vinyl sticker image was printed. on which the brand image was printed. 2.2 Methods 2.2 Methods Various tools were used for the production of the box and the design. Adobe programmes (Adobe Various tools were used for the production of the box and the design. Adobe programmes (Adobe Systems Inc., Systems Inc., USA) such as Photoshop and Illustrator were used to design the box. For the box USA) such as Photoshop and Illustrator were used to design the box. For the box construction Engview Packag construction Engview Packaging Suite (Engview Systems Corp., Bulgaria) was used. Cutter Esko -ing Suite (Engview Systems Corp., Bulgaria) was used. Cutter Esko Konsgberg X20 (Esko, Belgium) was used Konsgberg X20 (Esko, Belgium) was used for the cutting and production of final box. Canon for the cutting and production of final box. Canon imagePROGRAF PRO-4000S (Canon Inc., Japan) was used imagePROGRAF PRO-4000S (Canon Inc., Japan) was used for the print on vinyl label. for the print on vinyl label. 3. RESULTS WITH DISCUSSION 3. RESULTS WITH DISCUSSION 3.1 Designing the brand name, logo and packaging construction 3.1 Designing the brand name, logo and packaging construction For the brand name, we wanted something modern, easy to remember and easy to pronounce For the brand name, we wanted something modern, easy to remember and easy to pronounce internationally. The internationally. The name itself evokes associations with a figure, i.e. a shape, structure, sculpture, name itself evokes associations with a figure, i.e. a shape, structure, sculpture, statue. The name Figulina comes statue. The name Figulina comes from a Latin word whose direct translation is pottery. Phonetically, from a Latin word whose direct translation is pottery. Phonetically, Figulina sounds youthful and like a kind of Figulina sounds youthful and like a kind of diminutive, which gives it a soft sound. We experimented with diminutive, which gives it a soft sound. We experimented with very different ideas for the logo. We tried out differ very different ideas for the logo. We tried out different illustrated characters to represent the brand, word -ent illustrated characters to represent the brand, word logos in very different styles. We wanted to capture youth, logos in very different styles. We wanted to capture youth, playfulness, simplicity and originality in the playfulness, simplicity and originality in the logo. Examples of sketches can be seen in Figure 1a. We wanted to logo. Examples of sketches can be seen in Figure 1a. We wanted to incorporate the duality of clay, incorporate the duality of clay, which can be very soft at first and then very hard and sharp at different stages of which can be very soft at first and then very hard and sharp at different stages of its life. Clay can its life. Clay can withstand very high temperatures that harden it, but at the same time it can crack quickly when withstand very high temperatures that harden it, but at the same time it can crack quickly when struck, sharp and rounded edges, regular and irregular shapes on individual logos. We have mainly stuck to shapes that sharp and rounded edges, regular and irregular shapes on individual logos. We have mainly stuck to shapes that ultimately represent the letter "f" or the word Figulina, the brand name. struck, during and after firing, if handled carelessly. That is why in the sketches above we see in many cases during and after firing, if handled carelessly. That is why in the sketches above we see in many cases ultimately represent the letter “f” or the word Figulina, the brand name. a) b) c) Figure 1: Figure 1: a) sketches for the logo, b) moodboard of the first idea, c) moodboard of the second idea a) sketches for the logo, b) moodboard of the first idea, c) moodboard of the second idea packaging. To make our products even safer during transport to your home, we have come up with various solu As shown in Figure 2a, we first drew sketches of the desired packaging, then we drew constructions of As shown in Figure 2a, we first drew sketches of the desired packaging, then we drew constructions of the whole tions to protect our ceramic products even better against mechanical damage. We have produced different solu the whole packaging. To make our products even safer during transport to your home, we have come -tions, which we have tested for their stability during the transport of the products (Figure 2b). up with various solutions to protect our ceramic products even better against mechanical damage. We - have produced different solutions, which we have tested for their stability during the transport of the products (Figure 2b). 435 2 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia a) b) Figure 2: a) b) a) first construction of the desired packaging, b) solutions for additional packaging safety with a seat belt. Figure 2: a) first construction of the desired packaging, b) solutions for additional packaging safety with a seat belt. Figure 2: a) first construction of the desired packaging, b) solutions for additional packaging safety After the first cut, we adjusted the construction, corrected all errors and drew the final box with belt with a seat belt. After the first cut, we adjusted the construction, corrected all errors and drew the final box with belt solution and in-solution and inner part customisation (Figure 3a-b) . The packaging consists of the outer part where are ner part customisation (Figure 3a-b). The packaging consists of the outer part where are two pieces of cardboard two pieces of cardboard inserts (Figure 3b), which are optional and can be used as needed. The insert inserts (Figure 3b), which are optional and can be used as needed. The insert on the right-hand side in Figure After the first cut, we adjusted the construction, corrected all errors and drew the final box with belt on the right-hand side in Figure 3b is used when we want to give the product more stability, for example 3b is used when we want to give the product more stability, for example for taller products such as bowls, vases, solution and inner part for taller products such as bowls, vases, cups, etc. The insert on the left customisation (Figure 3a-b) . The packaging consists of the outer part where are-hand side (Figure 3b) is used cups, etc. The insert on the left-hand side (Figure 3b) is used to support products that do not reach exactly to the two pieces of cardboard inserts to support products that do not reach exactly to the top edge of our packaging. This keeps the product (Figure 3b), which are optional and can be used as needed. The insert top edge of our packaging. This keeps the product more stable and in place. The packaging must be glued in three on the right more stable and in place. The packaging must be glued in three parts. One is the flap on the far left of -hand side in Figure 3b is used when we want to give the product more stability, for example parts. One is the flap on the far left of the envelope that connects all sides of the box, the other two sections are for taller products such as bowls, vases, cups, etc. The insert on the left the envelope that connects all sides of the box, the other two sections are at the bottom of the box. This -hand side (Figure 3b) is used at the bottom of the box. This ensures that the bottom does not collapse when you are carrying heavier products. to support products that do not reach exactly to the top edge of our packaging. This keeps the product ensures that the bottom does not collapse when you are carrying heavier products. more stable and in place. The packaging must be glued in three parts. One is the flap on the far left of the envelope that connects all sides of the box, the other two sections are at the bottom of the box. This ensures that the bottom does not collapse when you are carrying heavier products. a) b) Figure 3: a) final construction of the packaging, b) solution for additional packaging safety. Figure 3: a) final construction of the packaging, b) solution for additional packaging safety. a) b) 3.2 a) final construction of the packaging, b) solution for additional packaging safety. Final logos, packaging design and the box 3.2 Final logos, packaging design and the box Figure 3: made up of letters that we designed ourselves. The advantages of word logos are quick recognisability, simplicity word logo made up of letters that we designed ourselves. The advantages of word logos are quick 3.2 Final logos, packaging design and the box and versatility of use, which would be very useful for a new business. Here’s how we went about creating the We spent a lot of time designing a symbol to represent the letter “F”, but in the end we decided on a word logo We spent a lot of time designing a symbol to represent the letter "F", but in the end we decided on a recognisability, simplicity and versatility of use, which would be very useful for a new business. Here's abstract logos from geometric and more organic shapes, which together would form the letter f (Figure 4). Due to organisation. First, we started with shapes and composed abstract logos from geometric and more how we went about creating the logo: First, we wrote down on a piece of paper the words we wanted to organic shapes, which together would form the letter f (Figure 4). Due to the nature of the letter f, which the nature of the letter f, which did not appear stable enough in our design attempts, we discarded this idea. We associate with the logo. These words were youth, uniqueness, creativity, freedom, simplicity and did not appear stable enough in our design attempts, we discarded this idea. We then focussed on a then focussed on a word logo that would be written in a slightly different, original way. Like every ceramic product, organisation. First, we started with shapes and composed abstract logos from geometric and more it is shaped by hand. youth, uniqueness, creativity, freedom, simplicity and organisation. First, we started with shapes and composed word logo made up of letters that we designed ourselves. The advantages of word logos are quick associate with the logo. These words were youth, uniqueness, creativity, freedom, simplicity and recognisability, simplicity and versatility of use, which would be very useful for a new business. Here's logo: First, we wrote down on a piece of paper the words we wanted to associate with the logo. These words were We spent a lot of time designing a symbol to represent the letter "F", but in the end we decided on a how we went about creating the logo: First, we wrote down on a piece of paper the words we wanted to organic shapes, which together would form the letter f (Figure 4). Due to the nature of the letter f, which did not appear stable enough in our design attempts, we discarded this idea. We then focussed on a 3 3 436 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia word logo that would be written in a slightly different, original way. Like every ceramic product, it is shaped by hand. word logo that would be written in a slightly different, original way. Like every ceramic product, it is shaped by hand. word logo that would be written in a slightly different, original way. Like every ceramic product, it is shaped by hand. ucts are fragile and should be handled with care, and second, that the box itself serves as a visually appealing packaged products are fragile and should be handled with care, and second, that the box itself serves the products it protects. This reminded us of In Figure 5, the illustrations on the box were designed to convey two key messages: first, that the extremely valuable ceramic products that are highly recognisable all over the world. It is Chinese as a visually appealing representation of the beauty of the products it protects. This reminded us of representation of the beauty of the products it protects. This reminded us of extremely valuable ceramic products packaged products are fragile and should be handled with care, and second, that the box itself serves porcelain, which is easily recognised by the white of the ceramic and the blue of the floral patterns on it. extremely valuable ceramic products that are highly recognisable all over the world. It is Chinese that are highly recognisable all over the world. It is Chinese porcelain, which is easily recognised by the white of as a visually appealing representation of the beauty of the products it protects. This reminded us of To match the logo, we modernised the flowers and used a simpler design with fewer details. The blue porcelain, which is easily recognised by the white of the ceramic and the blue of the floral patterns on it. the ceramic and the blue of the floral patterns on it. To match the logo, we modernised the flowers and used a extremely valuable ceramic products that are highly recognisable all over the world. It is Chinese and white ceramic was originally invented in China but quickly spread around the world. Today it is one To match the logo, we modernised the flowers and used a simpler design with fewer details. The blue simpler design with fewer details. The blue and white ceramic was originally invented in China but quickly spread porcelain, which is easily recognised by the white of the ceramic and the blue of the floral patterns on it. of the most famous products in the history of Chinese porcelain. It is generally ceramic decorated with and white ceramic was originally invented in China but quickly spread around the world. Today it is one To match the logo, we modernised the flowers and used a simpler design with fewer details. The blue around the world. Today it is one of the most famous products in the history of Chinese porcelain. It is generally cobalt blue colour, usually applied with a brush. Its charm lies precisely in the colour combination, which of the most famous products in the history of Chinese porcelain. It is generally ceramic decorated with and white ceramic was originally invented in China but quickly spread around the world. Today it is one ceramic decorated with cobalt blue colour, usually applied with a brush. Its charm lies precisely in the colour spread at the end of the 19th century and became an essential element of a beautiful home. cobalt blue colour, usually applied with a brush. Its charm lies precisely in the colour combination, which of the most famous products in the history of Chinese porcelain. It is generally ceramic decorated with combination, which spread at the end of the 19th century and became an essential element of a beautiful home. spread at the end of the 19th century and became an essential element of a beautiful home. cobalt blue colour, usually applied with a brush. Its charm lies precisely in the colour combination, which spread at the end of the 19th century and became an essential element of a beautiful home. In Figure 5, the illustrations on the box were designed to convey two key messages: first, that the packaged prod In Figure 5, the illustrations on the box were designed to convey two key messages: first, that the a) a) final logo, b) final packaging design. b) Figure 4: a) final logo, b) final packaging design. packaged products are fragile and should be handled with care, and second, that the box itself serves In Figure 5, the illustrations on the box were designed to convey two key messages: first, that the -as a visually appealing representation of the beauty of a) Figure 4: a) final logo, b) final packaging design. b) Figure 4: a) final logo, b) final packaging design. Figure 4: a) b) Figure 5: Final packaging with printed design. Since the safe transport of fragile products like ceramics was a primary concern, we developed an Figure 5: Final packaging with printed design. Figure 5: Final packaging with printed design. effective packaging solution featuring inner components that are securely fixed yet removable when Figure 5: Final packaging with printed design. Since the safe transport of fragile products like ceramics was a primary concern, we developed an effective pack needed (Figure 6a effective packaging solution featuring inner components that are securely fixed yet removable when -c). Since the safe transport of fragile products like ceramics was a primary concern, we developed an -needed (Figure 6a Since the safe transport of fragile products like ceramics was a primary concern, we developed an aging solution featuring inner components that are securely fixed yet removable when needed (Figure 6a-c). effective packaging solution featuring inner components that are securely fixed yet removable when -c). needed (Figure 6a-c). a) b) c) a) b) c) a) b) c) Figure 6: a) inner part of the packaging, b) inner part wih added product in the packaging, c) upper safety cover cardboard. 4 4 4 437 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Figure 6: a) inner part of the packaging, b) inner part wih added product in the packaging, c) upper safety cover cardboard. In the end, we decided in favour of the solution for fastening to the belt, which is shown in Figure 7a. At the same In the end, we decided in favour of the solution for fastening to the belt, which is shown in Figure 7a. At time, we managed to incorporate the brand image into this solution, as can be seen and added also. The elastic the same time, we managed to incorporate the brand image into this solution, as can be seen and added cords highlight intricate details (Figure 7b) in the flower, which are also reflected throughout the design. This solu also. The elastic cords highlight intricate details (Figure 7b) in the flower, which are also reflected -tion is user-friendly—simply pull the elastic over the belt and secure it onto the golden rivet at the bottom. throughout the design. This solution is user-friendly — simply pull the elastic over the belt and secure it onto the golden rivet at the bottom. a) b) Figure 7: Figure 7: a) fixed packaging during the transport, b) detail of the fastening solution, incorporated into design. a) fixed packaging during the transport , b) detail of the fastening solution, incorporated into design. on the Slovenian market. Our final packaging is very suitable for a wide range of ceramic products and also allows an advantage over existing packaging on the market. There is not much flexible cardboard packaging for fragile products on the Slovenian market. Our final packaging is very suitable for a wide range of the user to additionally protect the products with paper. It is flexible in the sense that we can store the products ceramic products and also allows the user to additionally protect the products with paper. It is flexible in in it in various ways. In the case of a tall vase, we used an insert with recesses to help provide stability to taller tage over existing packaging on the market. There is not much flexible cardboard packaging for fragile products The designed packaging is functional, aesthetically perfect and flexible. Above all, its flexibility gives it The designed packaging is functional, aesthetically perfect and flexible. Above all, its flexibility gives it an advan- cm wide. With the second insert, we reduced the risk of tipping damage and offer the option of storing products on enables the storage of products up to 16.5 cm high and 25.5 cm wide. With the second insert, we two levels. The insert is placed on top and with the sides on the surface we ensure that it stays in place. reduced the risk of tipping damage and offer the option of storing products on two levels. The insert is placed on top and with the sides on the surface we ensure that it stays in place. products with a diameter of 5.5 to 14 cm. Our box enables the storage of products up to 16.5 cm high and 25.5 insert with recesses to help provide stability to taller products with a diameter of 5.5 to 14 cm. Our box the sense that we can store the products in it in various ways. In the case of a tall vase, we used an 4. CONCLUSIONS 4. CONCLUSIONS Our research demonstrated that corrugated cardboard can be used to create packaging that meets all our re Our research demonstrated that corrugated cardboard can be used to create packaging that meets all - minimizing its environmental impact. Throughout the development process, we explored various design solutions, recyclable materials, minimizing its environmental impact. Throughout the development process, we explored various design solutions, prototyping and testing them under real conditions. To ensure stability quirements. Designed with sustainability in mind, the packaging is made from recycled and recyclable materials, our requirements. Designed with sustainability in mind, the packaging is made from recycled and selected and integrated into the final design. The most effective and eco-friendly solution was selected and integrated into the final design. Beyond the technical aspects of cardboard packaging, we also explored the significance of branding and market positioning. Our findings were implemented in the design process, successfully Beyond the technical aspects of cardboard packaging, we also explored the significance of branding and market moving car with three different seatbelt-locking mechanisms. The most effective and eco-friendly solution was during transport, we tested the box in a moving car with three different seatbelt-locking mechanisms. prototyping and testing them under real conditions. To ensure stability during transport, we tested the box in a positioning. Our findings were implemented in the design process, successfully demonstrating that functionality, demonstrating that functionality, aesthetics, and sustainability can be harmoniously integrated into this concept could be expanded into a series of packaging solutions in different sizes, accommodating a wider solutions in different sizes, accommodating a wider range of products. We hope our design will contribute to making the transportation of fragile ceramic items more secure and convenient. aesthetics, and sustainability can be harmoniously integrated into packaging for ceramic products. In the future, packaging for ceramic products. In the future, this concept could be expanded into a series of packaging range of products. We hope our design will contribute to making the transportation of fragile ceramic items more secure and convenient. 5 438 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Elkhattat, D., & Medhat, M. 2022. Creativity in packaging design as a competitive promotional tool. Information Sciences Letters, 11(1), 135-145. Gao, Z., Dong, W., & Xiaomin, J. 2021. Research on the reduction design of fragile product cushion packaging under the green development concept. In IOP Conference Series: Earth and Environmental Science, vol. 657, No. 1, 01205. Nguyen, V., Nguyen, N., Schumacher, B., & Tran, T. 2020. Practical application of plan–do–check–act cycle for quality improvement of sustainable packaging: a case study. Applied Sciences, 10(18), 6332. Sanchez-Belenguer, C., Vendrell-Vidal, E., Sánchez-López, M., Díaz-Marín, C., & Aura-Castro, E. 2015. Automatic production of tailored packaging for fragile archaeological artifacts. Journal on Computing and Cultural Heritage (JOCCH), 8(3), 1-11. Sundlof, B., & Fasano, B. 2007. Ceramics in Packaging. Global Roadmap for Ceramic and Glass Technology, 397-418. Xi, H., Guo, C., Yang, J., Wang, X., Wang, B., Huang, S., & Wang, Z. 2024. Cushioning Performance of a Novel Polyurethane Foam Material Applied in Fragile Packaging. Acta Mechanica Solida Sinica, 1-11. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author: Urška Vrabič-Brodnjak Sandra Grlj Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana, and Engineering Aškerčeva 12 Aškerčeva 12 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia urska.vrabic@ntf.uni-lj.si 439 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION SUSTAINABLE PRODUCTION OF BACTERIAL NANOCELLULOSE FROM KOMAGATAEIBACTER XYLINUS USING CITRUS PEEL AND GAMMA IRRADIATION Ivana Tartaro Bujak1, Maro Bujak1, Ivan Marić1, Anđela Pustak1, Mirjam Leskovšek2 and Urška Vrabič-Brodnjak2 1Ruđer Bošković Institute, Croatia 2 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Bacterial nanocellulose (BNC) is a promising natural biopolymer with unique structural and functional properties that make it valuable for various technological applications. However, large-scale production is limited by low yields and high costs of conventional culture media. In this study, cost-effective strategies to improve BNC production using agribusiness by-products, especially citrus peels, as alternative carbon sources are investigated. Additionally, gamma irradiation was used to improve the properties of BNC as it effectively modifies materials without chemical initiators. The results showed that irradiation affected the growth of Komagataeibacter xylinus and altered the morphology of BNC, improving its physical and chemical properties. The use of citrus peels offe-red an environmentally friendly, scalable approach to BNC production. This research emphasises the potential of waste materials and irradiation technology for sustainable BNC synthesis with improved properties. Keywords: Bacterial nanocellulose, ionizing radiation, biowaste, citrus peel. 1. INTRODUCTION Biomaterials play a crucial role in a variety of scientific and industrial applications, ranging from biomedical engi-neering to sustainable packaging. However, both natural and synthetic biomaterials are associated with limitations such as high cost, limited availability and potential toxicity, driving the search for innovative and environmentally friendly alternatives (Sarma, 2013; Arif, 2022). Among the emerging biopolymers, bacterial nanocellulose (BNC) has gained much attention due to its unique molecular structure, nanofibrillar network, excellent mechanical prop-erties and biocompatibility. These properties make BNC a valuable material for applications in biomedicine, elec-tronics, food packaging and tissue engineering. Despite its favourable properties, large-scale production of BNC faces significant challenges, mainly due to the low production yields and high costs associated with conventional culture media. Although conventional media such as Hestrin and Schramm (HS) provide optimal conditions for BNC biosynthesis, they are expensive and often unsuitable for industrial applications. Therefore, the search for cost-effective, sustainable alternatives for BNC production is crucial to enable commercial viability. Recent studies have investigated the potential of agro-industrial by-products as nutrient sources for microbial fermentation, offer-ing both economic and environmental benefits (Hadidi et. al., 2024, Valenzuela et.al., 2024). In particular citrus peels, which are abundant as waste materials in the fruit processing industry, contain important carbon sources that could support bacterial cellulose biosynthesis in a cost-effective manner. In addition to optimising culture media, improving the physicochemical properties of BNC is essential for expanding its applications. Radiation technology has proven to be a promising approach for the modification of biomaterials, as it enables structural changes without chemical additives or hazardous by-products. In contrast to conventional surface treatments, gamma irradiation penetrates the material and generates reactive intermediates that can affect the polymer struc-tures. Previous research has shown that high-dose irradiation can enhance enzymatic hydrolysis, change the crystallinity of cellulose and improve water solubility (Li, 2020). In addition, it has been reported that multiple irradi-ations and low-dose irradiation can significantly increase the yield of BNC, demonstrating its potential to increase production efficiency (Al-Hagar, 2022). In this study, we investigated the use of agro-industrial wastes, especially citrus peels, as an alternative carbon source for BNC production by Komagataeibacter xylinus. We also analysed the effects of gamma irradiation on BNC yield and structural properties. The morphology, mechanical properties 440 29–30 May 2025, Ljubljana, Slovenia and physicochemical attributes of BNC produced in citrus peel-based media were compared with those of BNC synthesised in conventional HS media. This study distinguishes itself by combining citrus peel-based media and gamma irradiation to enhance bacterial nanocellulose (BNC) production. The objectives are to: 1) explore citrus peels as a carbon source for BNC production, 2) evaluate the effects of gamma irradiation on BNC yield and properties, and 3) compare BNC produced in citrus peel-based and conventional media. This research aims to advance sustainable and scalable BNC production.By integrating waste materials and advanced processing methods such as irradiation, this research contributes to ongoing efforts to develop sustainable, scalable and high-performance biomaterials. 2. EXPERIMENTAL 2.1 Materials For BNC production, a strain of Komagataeibacter xylinus (Brown 1886), obtained from the culture collection of Leibniz institute (DSMZ), was used. The standard culture medium used in the experiments was the HS described by Hestrin and Schramm (1954) and modified by Hungund and Gupta (2010). The liquid medium contained 2.0% glucose (w/v), 0.5% yeast extract (w/v), 0.5% peptone, 0.27% Na HPO (w/v), and 0.15% citric acid (v/v). To for-2 4 mulate desolid medium, 1.8% agar (w/v) was added. The pH was adjusted to 5.0. The medium was stored at 4°C in a refrigerator. The citrus peel media was prepared as follows: citrus peels were boiled in 1L of water for one hour. The mixture was filtered to remove insoluble material. In 1L of the prepared citrus juice, 0.5% yeast extract (w/v), 0.5% peptone, 0.27% Na HPO (w/v), and 0.15% citric acid (v/v) were added. To formulate a desolid medi-2 4 um, 1.8% agar (w/v) was added. The pH was adjusted to 5.0. The process of growing the bacterial strain, forming the incubation and irradiation process was the same as for the HS media. The strain cultures were treated with gamma-ray. 0.2 and 0.5, kGy with singular and dual doses in parallel. The samples which underwent the irradia-tion treatment were then left to grow for 7 days and sub-cultured twice in fresh (HS) medium and /citrus media for 7 days each time to obtain the third generation, which re-irradiated with the corresponding radiation doses. The bacterial culture was incubated 28 ℃ for 10 days statically. At the end of the incubation session, the BNC films were collected and washed twice in boiling distilled water, and twice in 0.1 M NaOH solution, 15 min each time, prior to applying distilled water many times until the neutral pH of the BNC hydrogels was restored. The neutral hydrogels were maintained in distilled water in 4 ℃ until further examination. The wet BNC were dried in the oven for 5 hours at 60°C. 2.2 Methods For the final material analysis, a scanning electron microscope (SEM) (Jeol Ltd., Japan) was used at different magnifications with a voltage of 10 kV, along with dynamic mechanical analysis (DMA). The viscoelastic prop-erties of bacterial cellulose were investigated using DMA Q800 (TA Instruments, ZDA). The tension mode of deformation was performed with the amplitude of 10 μm and at the frequency of 10 Hz of oscillation. Dynamic frequency sweep tests were carried out from 0 to 250 ◦C in temperature, with a 3 ◦C/min heating rate. 3. RESULTS WITH DISCUSSION Scanning electron microscopy (SEM) analysis (Figures 1–3) revealed that gamma radiation influenced the for-mation of thinner nanofibers, with an average diameter below 100 nm, particularly in HS and orange media. This reduction in fibre diameter suggests a notable alteration in the nanostructure, likely due to the impact of gamma radiation on polymerization and cross-linking processes during BNC formation. Additionally, all irradiated samples exhibited an increased presence of bacterial traces, implying that while gamma irradiation affects nanofiber formation, it does not eliminate bacterial contamination. This bacterial presence may result from incomplete sterilization or suggest that modifications to the BNC fibril surface properties after irradia-tion enhance bacterial adhesion. The combined effects of thinner fibers, increased porosity, and bacterial traces highlight the intricate relationship between radiation and microbial cellulose synthesis. 441 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia a) b) c) a) b) c) d) e) f) Figure 1: BNC-2x200Gy, d) BNC-2x200Gy – with added diameter values of nanofibers, e) BNC - 2 x 500 Gy, f) SEM of a) BNC – control, b) BNC – control – with added diameter values of nanofibers, c) BNC-2x200Gy, d) BNC-d) e) f) BNC Figure 1: SEM of a) BNC – control, b) BNC – control – with added diameter values of nanofibers, c) 2x200Gy – with added diameter values of nanofibers, e) BNC - 2 x 500 Gy, f) BNC - 2 x 500 Gy – with added diameter values - 2 x 500 Gy – with added diameter values of nanofibers in HS media Figure 1: SEM of a) BNC – control, b) BNC – control – with added diameter values of nanofibers, c) of nanofibers in HS media BNC-2x200Gy, d) BNC-2x200Gy – with added diameter values of nanofibers, e) BNC - 2 x 500 Gy, f) BNC - 2 x 500 Gy – with added diameter values of nanofibers in HS media a) b) c) a) b) c) d) e) f) Figure 2: SEM of a) BNC – control, b) BNC – control – with added diameter values of nanofibers, c) BNC-2x200Gy, d) BNC-2x200Gy – with added diameter values of nanofibers, e) BNC - 2 x 500 Gy, f) BNC d) e) f) Figure 2: SEM of a) BNC - 2 x 500 Gy – with added diameter values of nanofibers in orange media – control, b) BNC – control – with added diameter values of nanofibers, c) Figure 2: BNC-2x200Gy, d) BNC-2x200Gy – with added diameter values of nanofibers, e) BNC - 2 x 500 Gy, f) SEM of a) BNC – control, b) BNC – control – with added diameter values of nanofibers, c) BNC-2x200Gy, d) BNC-2x200Gy – with added diameter values of nanofibers, e) BNC - 2 x 500 Gy, f) BNC - 2 x 500 Gy – with added diameter values BNC - 2 x 500 Gy – with added diameter values of nanofibers in orange media of nanofibers in orange media 3 3 442 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia a) b) c) d) e) f) Figure 3: SEM of a) BNC – control, b) BNC – control – with added diameter values of nanofibers, c) 2x200Gy – with added diameter values of nanofibers, e) BNC - 2 x 500 Gy, f) BNC - 2 x 500 Gy – with added diameter values BNC - 2 x 500 Gy – with added diameter values of nanofibers in tangerine media of nanofibers in tangerine media Figure 3: SEM of a) BNC – control, b) BNC – control – with added diameter values of nanofibers, c) BNC-2x200Gy, d) BNC-BNC-2x200Gy, d) BNC-2x200Gy – with added diameter values of nanofibers, e) BNC - 2 x 500 Gy, f) Figure 4: Dependence of storage modulus versus temperature for different media (HS, orange peel, tangerine peel) and irradiation conditions Figure 4: Dependence of storage modulus versus temperature for different media (HS, orange peel, tangerine peel) and Since the storage modulus represents the mechanical energy stored by the material during a loading irradiation conditions cycle (Figure 4 and Table 1), the loss tangent (tan delta) (Figure 5) describes the material's damping Since the storage modulus represents the mechanical energy stored by the material during a loading cycle (Fig-This parameter provides insight into the temperature range in which the material should not be subjected characteristics and reflects the extent of chain mobility influenced by oscillatory loading and temperature. ure 4 and Table 1), the loss tangent (tan delta) (Figure 5) describes the material’s damping characteristics and to significant mechanical loads. For most samples, this critical region falls between 20 – 80°C, where tan reflects the extent of chain mobility influenced by oscillatory loading and temperature. This parameter provides delta increases, reaches a peak, and then decreases. The subsequent rise in tan delta above 150°C is insight into the temperature range in which the material should not be subjected to significant mechanical loads. attributed to increased material viscosity due to thermal expansion. This behaviour defines how the For most samples, this critical region falls between 20–80°C, where tan delta increases, reaches a peak, and material absorbs and dissipates energy. Irradiation doses affected the elastic modulus (Table 1). In all then decreases. The subsequent rise in tan delta above 150°C is attributed to increased material viscosity due cases, samples exposed to double irradiation doses exhibited an increase in elastic modulus not only to thermal expansion. This behaviour defines how the material absorbs and dissipates energy. Irradiation doses at ambient temperature (25°C) but also across the entire heating range compared to the control. affected the elastic modulus (Table 1). In all cases, samples exposed to double irradiation doses exhibited an Changes in the elastic behaviour (storage modulus) of the samples result from alterations in crystallinity increase in elastic modulus not only at ambient temperature (25°C) but also across the entire heating range com and fibre network entanglement. The increased stiffness of irradiated HS, orange, and tangerine -pared to the control. Changes in the elastic behaviour (storage modulus) of the samples result from alterations samples can be attributed to higher crystallinity, where molecular chains are arranged in a more ordered 4443 29–30 May 2025, Ljubljana, Slovenia in crystallinity and fibre network entanglement. The increased stiffness of irradiated HS, orange, and tangerine samples can be attributed to higher crystallinity, where molecular chains are arranged in a more ordered lattice structure. Additionally, increased fibril connectivity within the bacterial cellulose (BC) network contributes to this stiffness. This enhanced connectivity arises from multiple interactions, including hydrogen bonding, electrostatic forces, hydrophobic interactions, van der Waals forces, and entanglement. The close packing and strengthened interactions restrict polymer chain mobility, thereby increasing BC toughness. The rigid BC fibrils provide greater resistance to applied forces, maintaining their structural integrity under mechanical stress. Some inconsistencies in the results require further investigation. Figure 5: Dependence of tan delta versus temperature for different media (HS, orange peel, tangerine peel) and irradiation conditions Table 1: The results of elastic modulus, E’ at room temperature (23 °C) Sample Elastic modulus, E‘ [GPa] BNC control – HS 8.92 2x200 Gy – HS 21.26 2x500 Gy – HS 28.31 BNC control – orange 18.81 2x200 Gy – orange 11.24 2x500 Gy – orange 14.72 BNC control– tangerine 13.56 2x200 Gy – tangerine 11.30 2x500 Gy – tangerine 16.29 4. CONCLUSIONS Gamma irradiation significantly enhances the mechanical properties of BNC by increasing stiffness, fibril con-nectivity, and crystallinity, which improves toughness and reduces polymer chain mobility. These changes also reveal a temperature-sensitive region, suggesting that mechanical loading should be minimized in specific con-ditions, while persistent bacterial traces indicate that complete sterilization may not be achieved. The use of biowaste-based media offers a sustainable, cost-effective approach to BNC production, which could facilitate large-scale applications. The remarkable modifications induced by gamma irradiation improve BNC’s suitability for diverse applications. Its enhanced properties make it ideal for biomedical engineering (e.g., wound dressings, tis-sue scaffolds, drug delivery systems), sustainable packaging, flexible electronics, and food packaging. Additional-ly, the environmentally friendly production process of BNC supports circular economy principles and improves its performance, offering a viable solution for large-scale, sustainable material production. 444 29–30 May 2025, Ljubljana, Slovenia 5. ACKNOWLEDGEMENTS This work was carried out in the framework of IAEA CRP F22081 “Strengthening the Use of Biomass for Synthesis of Bioplastics and Other Compounds, Using Radiation Technology” and their support is gratefully acknowledged. 6. REFERENCES Al-Hagar, O.E.A. and Abol-Fotouh, D. 2022. A turning point in the bacterial nanocellulose production employing low doses of gamma radiation. Sci. Rep. 12: 7012. Arif, Z.U., Khalid, M.Y. ,Sheikh, M. F., Zolfagharian, A., Bodaghi, M, 2022. Biopolymeric sustainable materials and their emerging applications. J. Environ. Chem. Eng. 10: 108159. Hadidi, M., Aghababaei, F., Gonzalez-Serrano, D. J., Goksen, G., Trif, M., McClements, D. J., & Moreno, A. 2024. Plant-based proteins from agro-industrial waste and by-products: Towards a more circular economy. International Journal of Biological Macromolecules, 129576. Hestrin S., Schramm M. 1954. Synthesis of cellulose by Acetobacter xylinum. Preparation of freeze-dried cells capable of polymerizing glucose to cellulose. Biochem. J. 58 345–352. 10.1042/bj0580345 Hungund B. S., Gupta S. G. (2010). Improved production of bacterial cellulose from Gluconacetobacter persimmonis GH-2. J. Microb. Biochem. Technol. 2 127–133. Li, T.; Wang, L., Chen, Z., Li, C., Li, X. and Sun, D. 2020. Structural changes and enzymatic hydrolysis yield of rice bran fiber under electron beam irradiation, Food Bioprod. Process. 122: 62−71 Sharma, C., Dinda, A.K., and Mishra, N.C. 2013. Fabrication and characterization of natural origin chitosan-gelatin-alginate composite scaffold by foaming method without using surfactant, J. Appl. Polym. Sci. 127: 3228–3241. Valenzuela, M., Ciudad, G., Cárdenas, J. P., Medina, C., Salas, A., Oñate, A., ... & Tuninetti, V. 2024. Towards the development of performance-efficient compressed earth blocks from industrial and agro-industrial by-products. Renewable and Sustainable Energy Reviews, 194, 114323. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-authors: Ivana Tartaro Bujak Maro Bujak Mirjam Leskovšek Bijenička c.54 Division of Materials Chemistry Faculty of Natural Sciences Bijenička c. 54 Ruđer Bošković Institute Ruđer Bošković Institute, University of Ljubljana 1000, Zagreb, Croatia and Engineering 10000, Zagreb, Croatia Snežniška 5 itartaro@irb.hr mbujak@irb.hr 1000, Ljubljana, Slovenia mirjam.leskovsek@ntf.uni-lj.si Ivan Marić Ruđer Bošković Institute, Urška Vrabič-Brodnjak Division of Materials Chemistry University of Ljubljana, Bijenička c. 54 Faculty of Natural Sciences 10000, Zagreb, Croatia and Engineering imaric@rb.hr Snežniška 5 1000, Ljubljana, Slovenia Anđela Pustak urska.vrabic@ntf.uni-lj.si Ruđer Bošković Institute, Division of Materials Chemistry Bijenička c. 54 10000, Zagreb, Croatia apustak@irb.hr 445 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION A GLOBAL ASSESSMENT OF COSMETIC PACKAGING TRENDS AND CONSUMER PREFERENCES Urška Vrabič-Brodnjak1 and Iva Jestratijević2 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2University of North Texas, College of Merchandising, Hospitality and Tourism, Texas, USA Abstract: This study explores the shift towards sustainable packaging in the cosmetics industry, focusing on the baby cosmetics sector. As the environmental impact of traditional packaging grows, the demand for eco-friendly solutions is rising. Analysing packaging claims from 2050 brands, including 76 specializing in baby cosmetics, the study identifies key trends. While sustainability efforts are promising, a lack of transparency raises concerns about actual environmental benefits, emphasizing the need for clear labelling and stronger regulations. Consumer preferences play a crucial role, as awareness of environmental issues grows. However, knowledge gaps persist regarding the true sustainability of materials, types of packaging, highlighting the need for brands to educate consumers and provide transparent information. The research highlights the importance of industry-wide collab-oration among companies, regulators, and consumers to establish sustainable practices as the norm. Ultimately, it calls for transparency, innovation, and responsibility, urging the cosmetics industry to prioritize sustainability, minimize environmental impact, and align with consumer expectations for a more eco-conscious future. Keywords: Consumer preferences, packaging solutions, sustainable statements, industry collaboration, con-sumer education. 1. INTRODUCTION In the cosmetics industry, there is a clear shift towards sustainable packaging solutions, driven by increasing en-vironmental concerns and growing consumer demand for environmentally friendly products (Le Pera et. al, 2023; Patel, 2023). This movement is particularly pronounced in the area of baby cosmetics, where parents are increas-ingly focussing on products that ensure the safety of their children and have as little impact on the environment as possible. Recent analyses show that many of baby cosmetics brands have introduced recyclable, refillable or bio-based packaging alternatives, reflecting a commendable commitment to environmental protection (Vrabič Brodn-jak & Jestratijević, 2023). However, transparency remains a critical issue, namely many of brands not disclosing their packaging materials, highlighting the need for clearer labelling and stricter regulations. As environmental awareness increases, many new generation parents are favouring brands that use biodegradable materials or are committed to eco-friendly practises (Savale et. al., 2023; Rosi et al., 2024). This trend emphasises the impor-tance of sustainable packaging in meeting consumer expectations and promoting environmental awareness in the baby cosmetics industry. The global biodegradable packaging market is expected to grow at a CAGR of 15.3% from 2023 to 2028, driven by rising demand in the cosmetics industry and other factors (Golden et. al., 2024). This growth is indicative of a broader industry trend towards sustainability, with companies exploring innovative materials and designs to reduce their environmental footprint. Despite this progress, there are still challenges. A significant number of brands lack transparency around their packaging materials, leading to consumer scepticism about the actual environmental benefits of supposedly sustainable products. This opacity underlines the urgent need for standardised labelling and a legal framework to ensure that sustainability claims are both accurate and verifiable. At the same time, consumer preferences are increasingly influencing market dynamics (Reddy et. al., 2023). As awareness of environmental issues grows, parents are more inclined to choose brands that demon-strate a genuine commitment to sustainability. However, there are still gaps in knowledge regarding the actual sustainability of different materials, which emphasises the need for brands to educate consumers and provide transparent information. Case studies within the industry showcase successful sustainable packaging initiatives that demonstrate the feasibility and benefits of such practises for brand reputation and consumer trust (Tjalsma, 446 29–30 May 2025, Ljubljana, Slovenia 2024). These examples serve as valuable role models for other companies looking to implement environmental-ly friendly solutions. The study emphasises the importance of industry-wide collaboration between companies, regulators and consumers to establish sustainable practises as the norm. Ultimately, it calls for transparency, innovation and responsibility and urges the cosmetics industry to prioritise sustainability, minimise environmental impact and adapt to consumer expectations for an environmentally conscious future. 2. EXPERIMENTAL This systematic review examined international baby cosmetic brands promoting sustainable packaging. Using data mining, only primary sources (official websites, sustainability reports) were included, while secondary sourc-es (social media, press articles) were excluded. From an initial 2048, only 79 were registered as a baby cosmetic brand, three were removed due to non-English websites or irrelevant sources, resulting in a final sample of 76 brands covering shampoos, lotions, and creams across Europe, America, Australia, and Asia. Thematic content clustering guided data analysis through five research stages: (1) search planning, (2) execution, (3) screening, (4) analysis, and (5) synthesis. To minimize researcher bias, a structured research protocol was established, outlining the study’s purpose, objectives, and methodology. Data collection was automated using a Python 3.6 web scrap-er. In the second stage, the web scraper accessed the internet via Hypertext Transfer Protocol (HTTP), identifying 79 baby cosmetic brands promoting sustainable packaging. The third stage involved manual verification and screening of websites to ensure data quality. Only primary sources were included, and non-eligible websites were excluded, resulting in a final sample of 76 brands. In the fourth stage, thematic content clustering was applied as a qualitative analytical method. Two researchers conducted thematic coding, resolving discrepancies through dis-cussion. Finally, the findings were synthesized and reported, providing insights into sustainable packaging trends within the baby cosmetics industry. 3. RESULTS WITH DISCUSSION The dilemma with cosmetics packaging lies in the balance between sustainability, functionality and aesthetics. While eco-friendly materials such as biodegradable plastics, refillable containers and glass packaging offer envi-ronmental benefits, they often come with higher costs, shelf-life concerns, and limited availability. Many brands advertise with “green” claims to attract conscious consumers, but a lack of transparency and clear regulations raises concerns about greenwashing. In addition, consumers are looking for sustainable options but may favour convenience and affordability. This tension emphasises the need for innovation, stricter regulations and consumer education to ensure that sustainability in cosmetic packaging is both effective and truly beneficial for the envi-ronment and human health. An analysis of the types of packaging used by cosmetics brands revealed notable trends in both material choice and packaging design. To better understand these trends, the research categorized cosmetic products according to FDA regulations (US Food and Drug Administration) as outlined in Table 1 (Vrabič Brodnjak, Jestratijević, 2024). 447 29–30 May 2025, Ljubljana, Slovenia Table 1: Categories of cosmetic products based on the FDA. Categories Cosmetic products 1. Baby Products 2. Bath Preparations 3. Eye Makeup Preparations 4. Fragrance Preparations 5. Hair Preparations (non-colouring) 6 Hair Colouring Preparations 7. Makeup Preparations (not eye) 8. Manicuring Preparations 9. Oral Hygiene Products 10. Personal Cleanliness 11. Shaving Preparations 12. Skin Care Preparations 13. Suntan Preparations Baby cosmetic products were divided into three main categories: Baby shampoos, lotions/oils/powders/creams and other baby care products. Baby shampoos are specially formulated for baby’s delicate skin and hair and often do not contain harsh chemicals that could cause irritation or dryness. Many baby shampoos are also tear-free to avoid discomfort if the product accidentally gets into the baby’s eyes. Lotions, oils, powders and creams are de-signed to moisturise and protect your baby’s skin. These products help to soothe dry skin, prevent diaper rash and provide relief from various skin conditions. Like the baby shampoos, they are gentle and safe for baby’s sensitive skin. Other baby products include a wide range of products that do not fall into the first two categories, such as baby lip balm for chapped lips, baby toothpaste that must not be swallowed, and wet wipes for diaper changes or cleaning baby’s face and hands. These products are designed to be gentle and non-irritating to baby’s skin. Results of categories that brands are using is presented in Figure 1. Figure 1: Number of brands and cosmetic categories based on FDA. 448 29–30 May 2025, Ljubljana, Slovenia Seventeen of the brands analysed belong to 3 cosmetics categories, including the baby cosmetics category. There are only 6 brands that include 6 or more categories of different cosmetic products but also offer baby cos-metics. Worldwide, only 14 cosmetics brands have only 1 cosmetics category, and that is baby cosmetics. Sustainable packaging solutions, such as the use of biodegradable or compostable materials, recycled materials and designs that minimise the use of materials, energy and resources, are increasingly favoured in the industry. Other sustainable practises include the use of renewable energy in production and efforts to reduce emissions through improved supply chain and logistics management. The most common packaging type was the tube, used by 68 brands (28.33%), especially for products such as toothpaste, sunscreen and facial cleanser, as it is lightweight and user-friendly. Containers, commonly used for creams and lotions, were the second most common packaging type, used by 62 brands (25.83%). Boxes, typical-ly used as secondary packaging, ranked third with 50 brands (20.83%), followed by bottles, commonly used for shampoos, conditioners and body washes, used by 48 brands (20%). Pouches were used by 11 brands (4.58%) and envelopes by only 1 brand (0.42%). In addition, 2 brands (0.83%) did not define their packaging type. Of the 76 brands analysed, 30 brands (39%) did not specify the materials used in their packaging, while 46 brands (61%) reported using recyclable or bio-based packaging materials (Figure 2). This reflects an increasing trend towards sustainability in the cosmetics industry. However, the high proportion of brands that do not provide infor-mation on their packaging materials shows a lack of transparency. Figure 2: Number of brands and specified materials in their packaging solutions. The high percentage of brands with undefined packaging materials raises concerns about accountability and high-lights the need for better regulation and standardisation within the industry. These findings suggest that while there is a clear movement towards more sustainable packaging options, cosmetics companies need to make greater efforts to fully adopt these practises and provide transparent information to consumers. Such measures are cru-cial to move the industry towards more sustainable and environmentally friendly packaging solutions. In addition to the packaging types, the study analysed the materials used, identifying both sustainable and non-sustainable options. Among the brands analysed, recyclable plastic proved to be the most commonly used material, used by 31 brands. Despite its recyclability, issues such as contamination and inadequate recycling infrastructure can compromise the environmental benefits of this material. Paper and cardboard, known for their renewability and biodegradability, were the most important materials for 25 brands, signalling a positive shift towards sustainability. Aluminium, a durable but energy-intensive material, was used by 17 brands. Biodegradable and compostable plastics, which are considered environmentally friendly alternatives, were used by 6 brands, signalling a growing 449 29–30 May 2025, Ljubljana, Slovenia interest in sustainable innovation. A combination of materials, including paper, cardboard and recycled plastic, was used by 15 brands, while a further 5 brands combined paper, cardboard and biodegradable or compostable materials, further increasing their sustainability efforts. However, a worrying trend was observed as 30 brands did not define their primary packaging material, raising questions of transparency around sustainability claims. The results show that the cosmetics industry is taking different approaches to sustainable packaging. Whilst many brands have introduced recyclable, biodegradable or renewable materials, the lack of transparency and continued use of unsustainable materials remains a challenge. Promoting clear labelling and informed consumer choices will be key to making further progress in sustainable packaging practises. 3.1 Consumer perception of packaging in the cosmetics industry In terms of consumer preferences, there is a clear global shift towards sustainable packaging, with an increas-ing number of consumers prioritizing eco-friendly options. However, consumer perceptions are often influenced by convenience and cost, which can sometimes lead to a preference for non-sustainable options despite an expressed desire for more environmentally responsible choices. This tension between sustainability and conve-nience highlights the need for brands to find a balance that meets both consumer demands and environmental goals. A significant challenge identified in the assessment is the lack of transparency in packaging materials and sus-tainability claims. Consumers are often confused about the environmental benefits of different materials, such as recyclable plastics and biodegradable options. This confusion is exacerbated by the prevalence of greenwashing, where brands make unsubstantiated sustainability claims to attract eco-conscious consumers. Clear labelling, material transparency, and sustainability certifications are essential to building trust and enabling consumers to make informed choices. Notably, in the baby cosmetics sector, consumer preferences are even more pronounced, with parents prioritizing safety and sustainability. The desire for non-toxic packaging materials, such as BPA- and phthalate-free plastics, is central to purchasing decisions. In this segment, packaging that is hygienic, convenient, and easy to use is critical, and there is a growing demand for refillable or reusable packaging options. Favourite packaging types, such as tubes and containers, meet consumer expectations in terms of ease of use and conve-nience. The choice of material also plays a crucial role in consumer perception. While recyclable plastics are used by many brands, they often cause confusion among consumers who do not fully understand the limitations of recy-cling due to contamination or lack of infrastructure. Paper and cardboard packaging, on the other hand, is gener-ally well received as it is considered environmentally friendly and biodegradable. Although aluminium is durable, it raises concerns due to the high energy consumption during production. Biodegradable and compostable plastics are gaining traction with environmentally conscious consumers, but limited awareness of their actual degradation process remains a challenge. Consumers are also strongly influenced by the transparency of packaging. When brands fail to disclose their primary packaging materials, this can lead to scepticism and a lack of trust in sus-tainability claims. Clear labelling, sustainability certifications and material composition claims are crucial to boost consumer confidence. In addition, aesthetics and a high-quality packaging experience are still important, as many consumers associate high-quality packaging with product effectiveness and luxury. In the area of baby cosmetics, the perception of packaging is even more sensitive, as parents prioritise safety, sustainability and the protection of ingredients. Parents expect baby cosmetics packaging to be free from harmful chemicals such as BPA and phthal-ates to ensure that the materials do not leach into the skincare products. Tubes and pump bottles are among the preferred packaging types for baby shampoos, lotions and creams as they are hygienic and easy to handle. The issue of sustainability is particularly important in this sector, as parents are more likely to opt for brands that prior-itise environmentally friendly packaging (Vrabič Brodnjak & Jestratijević, 2024). Paper and cardboard packaging are perceived as safer alternatives for outer packaging, while biodegradable plastics are seen as a responsible innovation. However, similar to cosmetics in general, consumers still lack knowledge about the actual environ-mental benefits of the different materials. The functionality of the packaging also plays an important role in the purchasing decision. Parents prefer leak-proof, easy-to-use designs that can be operated with one hand during baby care. Brands that offer refillable or reusable packaging solutions are also gaining traction as they cater to growing environmental awareness and offer consumers long-term cost savings. For both general and baby cos-metics, consumer perception is a complex interplay of sustainability, safety, convenience and brand trust. 450 29–30 May 2025, Ljubljana, Slovenia To improve the perception and acceptance of sustainable packaging, brands need to focus on clear commu-nication, education and innovative design solutions that meet consumer expectations. Given the complexity of balancing sustainability with functionality and aesthetics, it is essential for brands to work together, share best practices, and align on standards that promote environmental responsibility. Collaboration between companies can lead to innovative solutions that address the challenges of cost, material availability, and waste reduction. Regulators play a crucial role in setting clear and enforceable standards that prevent greenwashing, ensuring that sustainability claims are transparent and reliable. At the same time, consumer education is key to fostering informed decision-making and driving demand for genuinely sustainable packaging options. By working together, these stakeholders can create a unified approach that accelerates the adoption of sustainable packaging practic-es and drives the cosmetics industry toward a more environmentally responsible future. 4. CONCLUSIONS The cosmetics industry’s pursuit of sustainable packaging has seen significant progress but still faces challenges. Many brands have adopted eco-friendly materials like recyclable plastics, biodegradable alternatives, and pa-per-based packaging, but continued reliance on unsustainable materials and lack of transparency hinder further progress. Consumer demand for sustainable packaging is growing, but perceptions are influenced by conve-nience, material transparency, and environmental impact, with many consumers unaware of the actual benefits and limitations of materials. Clear communication and education on sustainable practices are essential. In the baby cosmetics sector, safety, sustainability, and functionality are especially important, with parents preferring non-toxic, easy-to-use, and hygienic packaging, with a growing interest in refillable or reusable options. A global assessment of packaging trends shows increasing use of sustainable materials but highlights low consumer awareness of the environmental impact. Greenwashing adds to consumer confusion, underscoring the need for transparency and industry-wide collaboration. Clear labelling, sustainability certifications, and education will boost consumer confidence and enable informed purchasing decisions. For the cosmetics industry to meet the demand for sustainable packaging and contribute to environmental sustainability, brands, regulators, and consumers must collaborate effectively. Integrating clear labelling, consumer education, and innovative design will be key to driving meaningful change. Aligning sustainability with consumer expectations and ensuring transparency will help the industry make significant strides towards a responsible future. 5. REFERENCES Golden, J. S., Handfield, R. B., Daystar, J., & Pires, S. 2024. An Economic Impact Analysis of the US Biobased Products Industry: 2023 Update. Le Pera, A., Sellaro, M., Grande, G., Bencivenni, E., & Migliori, M. 2023. “Effect of quality of separately collected glass, paper plus cardboard and lightweight packaging waste on environmental, energetic and economic sustainability of the material recovery facility operations“. Journal of Cleaner Production, 425, 138973. Patel, K. R. 2023. “Harmonizing sustainability, functionality, and cost: navigating responsible packaging innovations in modern supply chains“. American Journal of Economic and Management Business (AJEMB), 2(8), 287-300. Reddy, K. P., Chandu, V., Srilakshmi, S., Thagaram, E., Sahyaja, C., & Osei, B. 2023. “Consumers perception on green marketing towards eco-friendly fast moving consumer goods“. International Journal of Engineering Business Management, 15, 18479790231170962. Rossi, M., Cappelletti, F., Manuguerra, L., Mundo, M., & Germani, M. 2024. “Ecodesign Strategies for Packaging: a Simplified Approach to Evaluate Environmental Benefits“. Procedia CIRP, 122, 330-335. Savale, T. K., Byram Anand, P., Perumalla Varalaxmi, A. B., & Quaye, J. A. 2023. Green Marketing Strategies: Assessing Consumer Perception and Adoption of Eco-friendly Products. Remittances Review, 8(4). Tjalsma, D. 2024. The Supermarket of the Future: A Case Study on the Transition towards Sustainable Packaging (Master’s thesis, University of Twente). Vrabič ‐Brodnjak, U., & Jestratijević, I. 2024. The future of baby cosmetics packaging and sustainable development: A look at sustainable materials and packaging innovations–A systematic review. Sustainable Development, 32, 2208–2222. 451 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author: Urška Vrabič Brodnjak Iva Jestratijević University of Ljubljana University of North Texas Faculty of Natural Sciences College of Merchandising, and Engineering Hospitality and Tourism Aškerčeva 12 410 S. Avenue C Denton, TX 76201, USA 1000 Ljubljana, Slovenia urska.vrabic@ntf.uni-lj.si 452 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION PACKAGING PAPERS’ ANTIMICROBIAL PROPERTIES THROUGH NATIVE CHEMICAL ADDITIVES TREATMENT OR COATING Urška Vrabič-Brodnjak1, Dimitrina Todorova2 and Nikolay Yavorov2 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2 University of Chemical Technology and Metallurgy, Faculty of Chemical Technology, Bulgaria Abstract: Study evaluates the antimicrobial properties of packaging paper treated with lavender essential oil, silver nanoparticles (AgNPs) and chitosan coatings. These additives are known for their antimicrobial efficacy due to their physicochemical properties. A cellulose mixture (80:20 bleached softwood and hardwood) was used, with the base paper prepared by adding wet-end chemicals. Antimicrobial activity was tested against nine micro-organisms, including Gram-positive and Gram-negative bacteria, yeasts and fungi. The results showed that paper treated with lavender oil exhibited decreasing antimicrobial activity, with efficacy ranging from 42.9% to 67.2%. AgNP-treated paper (3 mL/20 cm²) demonstrated the highest antibacterial protection (81.6% for S. aureus, 75.8% for E. coli), with lower efficacy at lower concentrations. Chitosan-coated paper (2 g/m²) provided the most con-sistent protection (79% on average) for all microorganisms tested. Gram-positive bacteria, yeasts and fungi were more sensitive to chitosan. The results emphasize the potential of these treatments for antimicrobial packaging applications. Keywords: Lavender oil; silver nanoparticles; chitosan; packaging paper; antibacterial. 1. INTRODUCTION The rising concerns about food safety, shelf-life extension, and environmental sustainability have led to increased interest in antimicrobial packaging materials. Foodborne pathogens and spoilage microorganisms pose signif-icant challenges to the food industry, leading to contamination, foodborne illnesses, and economic losses (De Matteis, 2023). Traditional packaging materials primarily act as passive barriers, offering no antimicrobial func-tionality. To address these challenges, active packaging technologies have been developed to enhance the pro-tective functions of packaging materials by incorporating antimicrobial agents that inhibit microbial growth directly on the surface of packaged products. Among various antimicrobial agents, natural additives and nanomaterials have gained significant attention due to their potential to replace synthetic preservatives, which are often as-sociated with health risks and regulatory restrictions. Essential oils (EOs), silver nanoparticles (AgNPs), and polysaccharide-based coatings, such as chitosan, have emerged as promising antimicrobial agents due to their biocompatibility, biodegradability, and broad-spectrum antimicrobial activity. These compounds can be incorpo-rated into packaging materials as coatings, embedded into films, or applied as surface treatments to enhance their antimicrobial effectiveness. Lavender (Lavandula angustifolia Mill.) essential oil has been widely studied for its antimicrobial properties, primarily due to its high content of bioactive compounds such as linalool and linalyl acetate (Kuorwel, 2011; Predoi, 2018). These compounds exhibit strong antibacterial and antifungal activities by disrupting microbial cell membranes and inhibiting enzymatic functions. Similarly, AgNPs have been extensively used for their antimicrobial efficiency, attributed to their ability to release silver ions, which interact with microbi-al cell walls, disrupt metabolic pathways, and ultimately lead to cell death (Kumar, 2021). Chitosan, a naturally occurring biopolymer derived from chitin, has been recognized for its antimicrobial and film-forming properties. Due to its cationic nature, chitosan interacts with negatively charged microbial membranes, causing membrane destabilization, leakage of intracellular contents, and microbial inactivation (Zhang, 2023). While the antimicrobial potential of these agents has been extensively studied in various applications, their direct integration into paper-based packaging materials remains underexplored. Paper packaging is widely used in the food industry due to its renewability, biodegradability, and recyclability. However, its porous structure makes it 453 29–30 May 2025, Ljubljana, Slovenia susceptible to microbial contamination, necessitating the development of antimicrobial modifications to enhance its functionality. In this study, we investigate the antimicrobial performance of packaging paper treated with lav-ender essential oil, AgNPs, and chitosan coatings. The antimicrobial efficacy of these treatments was evaluated against nine microbial strains, including Gram-positive and Gram-negative bacteria, yeasts, and fungal species, to determine their potential application in active packaging systems. The findings from this study contribute to the growing body of knowledge on antimicrobial packaging materials and provide valuable insights into the practical application of natural and nanomaterial-based antimicrobial agents in paper-based packaging. By comparing the effectiveness of these treatments, we aim to identify the most suitable antimicrobial approach for improving the safety and shelf life of packaged products while maintaining the sustain-ability of paper-based packaging solutions. 2. EXPERIMENTAL 2.1 Materials and Preparation Procedures For paper samples preparation, in ratio 80:20, a cellulose mixture from two kraft bleached wood-free pulps was used. Both, softwood cellulose - SCA, Sweden and hardwood cellulose - Svilosa AD, Bulgaria were separately refined using laboratory Valley beater, according to ISO 5264-1:1979. The average beating degree of the pulp mixture obtained was 30 °SR (Schopper Riegler value), in accordance with ISO 5267-1:1999/Cor 1:2001. For the base paper samples obtaining, two wet-end chemical additives were added sequentially: alkylketendimer sizing agent - 1% of o.d.f (Kemira® Fennosize KD 157YC) and cationic retention additive - 0.025% of o.d.f. (cationic modified polyacrylamide with 11.106 g/mol molecular weight and +1.05 charge density delivered by Ciba® Percol® Co. Rapid-Köthen laboratory paper-sheet machine (Birkenau, Germany) was used for the laboratory papermak-ing process. With base weight of 50 g/m2 and in according to ISO 5269-2:2004 samples were prepared and dried under 90 kPa pressure at 95 °C temperature with duration of 7 min. The experimental investigations were conducted with nine paper samples, described in Table 1. Table 1: Composition of investigated paper samples. CSAgNPs Lavender Chitosan Paper samples Description Treatment treatment coating (g/ (mL/20 cm2) (mg/cm2) m2) OP Mixture of only pulp - - - BP (control) Base paper - - - BP/CSAgNPs 2 Base paper treated with silver BP/CSAgNPs 1 1 - - BP/CSAgNPs 3 water 2 - -3-- BP/LEO Base paper treated with lavender - 0.8 -essential oil BP/Ch 1 Base paper coated with BP/Ch 0.5 - - 0.5 BP/Ch 2 chitosan - - 1--2 By sparing onto the obtained 20 cm2 base paper samples silver nanoparticles treatment with 1-, 2- and 3-mL con-sumption of Arcol® colloidal silver solution containing silver nanoparticles suspended in a liquid base (CSAgNPs), delivered from Gal ET was applied from 20 cm distance and is having concentration of 10 mg/L = 0.00001 g/L. Using a sprayer on both sides of pre-weighed paper squares of 5x5 cm the lavender essential oil (LEO) was ap-plied and let dry at room temperature (25°C) for 30 minutes. The dried paper samples were weighed again and the amount of essential oil was calculated. Results indicated that the average amount of lavender EO was 0.8 mg/ cm2. The relative density () of the used LEO is 0.8862 ± 0.05, its refractive index () is 1.4626±0,02, polarization 454 29–30 May 2025, Ljubljana, Slovenia coefficient (α ) is -8±0,02 and acid number, (mg KOH/g oil) 0,9±0,04. Thirty-five ingredients were identified in the used LEO, representing 99.69% of the total amount of substances. Ten of them are in concentrations above 1%, and the remaining twenty-five ingredients are in concentrations below 1%. In an amount above 4% are six com-pounds: linalyl acetate (36.05%), β-linalool (27.67%), terpinene-4-ol (6.13%), β-cis-ocimene (5.52%), lavandulyl acetate (4.87%), β-car-yophyllene (4.68%). According to ISO 3515 /2017, β-trans-ocimene (1.79%) is below the lower limit (2.0–5.0%) and terpinene-4-ol (6.13%) is above the upper limit (2.0–5.0%). The main components in lavender oil are linalool and linalyl acetate, and their total amount is 63.72% (Todorova, 2023). Fluka® 28191 (BioChemika, Japan) crayfish chitosan (2-Amino-2-deoxy-(1->4)-β-D-glucopyranan) with medium viscosity and acetic acid - 99.8% with M = 60.05 g/mol was used for the base paper coating. At constant stirring at 300 rev/min for 24 h on a magnetic stirrer and heating to 50 °C in the first 2 h, 1 g of chitosan (Ch) was dissolved in 1% (v/v) aqueous acetic acid (100 mL) to complete dissolving. The obtained chitosan solution was with viscosity of 300 mPas-1. Laboratory coating machine K Control Coater (RK PrintCoat, UK) was used for the paper samples’ coating process, done at ambient temperature. Stainless steel wet film deposit K-bar 120 µm with wire diameter 1.52 mm was used. The drying of the coated samples was done in a vacuum dryer with P = 0.08 MPa at t = 50 °C till its complete drying. The resulting chitosan coating layers were, respectively 0.5 g/m2, 1 g/m2 and 2 g/m2. 2.2 Antimicrobial Testing The antimicrobial testing was performed with nine microorganisms – two Gram-positive bacteria (Staphylococ-cus aureus ATCC 6538; Bacillus cereus АТСС 10876), three Gram-negative bacteria (Esсherichia coli ATCC 8739; Pseudomonas aeruginosa ATCC 9027; Salmonella abony NTCC 6017), two yeast (Candida albicans ATCC 10231; Saccharomyces cerevisiae ATCC 2601) and two fungal strains (Aspergillus brasiliensis ATCC 16404; Fusarium moniliforme). For bacteria growth, samples were cultured in an incubation chamber at 30-35 °C for 24-48 h and at 20-25 °C for 48-72 h for yeast and 120 h for fungal. From each bacterial test microorganism a 24 h culture was prepared. Vegetative material was taken using a wire loop and suspended in 10 mL of saline (0.9% sodium chloride solution (0.154 mol/L). The cell concentration of the suspensions prepared were of about 103 CFU/mL. Analogously, the yeast and mould suspensions, with 48 h cultivation time for yeast and 120 h for mould, respectively. In aseptic conditions with sterile tweezers, each paper sample was placed in a petri dish. On each square with sterile pipette 0.1 mL of the prepared cell suspensions was dropped and carefully spread over the surface, then placed in an incubation chamber for 2 h at 30-35 °C. Aseptically with a sterile pipette, in every petri dish were dropped 20 mL of soybean casein agar for bacteria or Sabouraud-dextrose agar for yeast and moulds. For bacteria growth, samples were cultured in an incubation chamber at 30-35 °C for 24-48 h and at 20-25 °C for 48-72 h for yeast and 120 h for mould. The colonies grown in the petri dishes were counted by a colony counter. The effect on the growth of test microorganisms was evaluated by the antimicrobial efficiency the antimicrobial efficiency calculated by the Equation 1: % N − N Efficiency = 01 ×100 N 0 , (1) Where N was the number of the colony-forming units in the control sample, while N – in the treated and coated 0 1 samples. One-way ANOVA with a confidence level of 95% (p<0.05) statistical analysis was carried out using Microsoft® Excel 2016 with ToolPak data analysis. 455 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 3. 3. RESULTS WITH DISCUSSION RESULTS WITH DISCUSSION The applicability in the forms of treatments, films or coatings of native chemical additive such as essential oils, The applicability in the forms of treatments, films or coatings of native chemical additive such as essential oils, silver nanoparticles (AgNPs) or polysaccharides such as chitosan have attracted great silver nanoparticles (AgNPs) or polysaccharides such as chitosan have attracted great interest in the field of anti-interest in the field of antimicrobial packaging due to their unique physicochemical properties, especially microbial packaging due to their unique physicochemical properties, especially their high surface-to-volume ratio, their high surface-to-volume ratio, which enhances their interaction with microbial cells (De Matteis, which enhances their interaction with microbial cells (De Matteis, 2023). Lavender (Lavandula angustifolia Mill.) is 2023). Lavender (Lavandula angustifolia Mill.) is a popular raw material for widely used aromatic a popular raw material for widely used aromatic products. Its’ essential oil has a high content of linalyl acetate and p roducts. Its’ essential oil has a high content of linalyl acetate and linalool characterizing its’ antimicrobial linalool characterizing its’ antimicrobial efficiency (Kuorwel, 2011; Predoi, 2018). The antimicrobial mechanism of efficiency (Kuorwel, 2011; Predoi, 2018). The antimicrobial mechanism of AgNPs primarily involves the AgNPs primarily involves the release of silver ions, which can penetrate microbial cell membranes, disrupt cell release of silver ions, which can penetrate microbial cell membranes, disrupt cell function and ultimately function and ultimately lead to cell death (Kumar, 2021). Chitosan’s unique properties arise from its cationic na-lead to cell death (Kumar, 2021). Chitosan's unique properties arise from its cationic nature, which allows ture, which allows it to interact with negatively charged microbial cell membranes, leading to the destruction of the it to interact with negatively charged microbial cell membranes, leading to the destruction of the cell wall cell wall and the death of the microbes (Zhang, 2023). The inhibition efficiency of the CSAgNPs and LEO treated and the death of the microbes (Zhang, 2023). The inhibition efficiency of the CSAgNPs and LEO treated paper samples against Gram-positive and Gram-negative bacteria, yeast and fungal strain are presented in Table paper samples against Gram-positive and Gram-negative bacteria, yeast and fungal strain are 2, while the chitosan coating efficiency in Table 3. presented in Table 2, while the chitosan coating efficiency in Table 3. Table 2: Table 2: Inhibition efficiency of the CSAgNPs and LEO treated paper samples against Gram-positive and Inhibition efficiency of the CSAgNPs and LEO treated paper samples against Gram-positive Gram-negative bacteria, yeast and fungal strain. and Gram-negative bacteria, yeast and fungal strain. e treatments (%) pl Inhibition efficiency of CSAgNPs and LEO m Tested microorganisms BP/ BP/ BP/ BP/LEO Sa CSAgNPs 1 CSAgNPs 2 CSAgNPs 3 A Gram- Staphylococcus aureus ATCC 47.5 67.3 81.6 62.9 positive 6538 B bacteria Bacillus cereus АТСС 10876 11.7 31.5 40.4 51.3 C Esсherichia coli ATCC 8739 46.8 66.0 75.8 67.2 Gram-Pseudomonas aeruginosa ATCC D negative 16.3 20.4 38.8 54.8 9027 bacteria E Salmonella abony NTCC 6017 27.7 35.7 45.6 42. 9 F Candida albicans ATCC 10231 18.6 34.4 37.1 53.1 G Yeast Saccharomyces cerevisiae 33.4 41.1 51.2 56.6 ATCC 2601 H Aspergillus brasiliensis ATCC Fungal 15.1 28.3 35.5 44.3 16404 strain I Fusarium moniliforme 27.1 33.8 36.9 49.2 3 mL/20cm 3 mL/20cm2 CSAgNPs treated paper samples (BP/CSAgNPs 3) inhibited the growth of the Gram-2 CSAgNPs treated paper samples (BP/CSAgNPs 3) inhibited the growth of the Gram-positive bac-positive bacterium S. aureus with 81.6% and the Gram-negative bacterium E. coli with 75.8%. The terium S. aureus with 81.6% and the Gram-negative bacterium E. coli with 75.8%. The inhibition efficiency is inhibition efficiency is weaker compared to Gram-negative S. abony (45.6%) bacterium and the yeast weaker compared to Gram-negative S. abony (45.6%) bacterium and the yeast S. cerevisiae (51.2%). This type S. cerevisiae (51.2%). This type of paper has around and below 40% antimicrobial activity against Gram-of paper has around and below 40% antimicrobial activity against Gram-positive bacterium B. cereus (40.4%), P. positive bacterium B. cereus (40.4%), P. aeruginosa (38.8%), yeast C. albicans (37.1%), fungal strain aeruginosa (38.8%), yeast C. albicans (37.1%), fungal strain A. brasiliensis (35.5%) and F. moniliforme (36.9%). A. brasiliensis (35.5%) and F. moniliforme (36.9%). Less effective is the treatment of the paper with 1 Less effective is the treatment of the paper with 1 and 2 mL/20cm 2 of CSAgNPs - 27.13 and 39.83%, respective-and 2 mL/20cm 2 of CSAgNPs - 27.13 and 39.83%, respectively. The CSAgNPs treatment is most ly. The CSAgNPs treatment is most efficient for the Gram-positive bacteria (with about 106%), followed by the efficient for the Gram-positive bacteria (with about 106%), followed by the Gram-negative with an Gram-negative with an efficiency of about 77% and 74.8% for the fungal strains and yeast from 70%. The order of efficiency of about 77% and 74.8% for the fungal strains and yeast from 70%. The order of the group’s the group’s effectiveness is confirmed while comparing the microorganisms group, except for the yeast and fungal effectiveness is confirmed while comparing the microorganisms group, except for the yeast and fungal strain, with exchanged positions. strain, with exchanged positions. The inhibition efficiency of the LEO treated paper is in the range of 62.9% and 51.3% against Gram-positive bac The inhibition efficiency of the LEO treated paper is in the range of 62.9% and 51.3% against Gram--teria positive bacteria S. aureus and S. aureus B. cereus and . Against Gram-negative bacteria it is in the range of 67.2% for B. cereus . Against Gram-negative bacteria it is in the range of 67.2% for E. coli , 54.8% at P. aeruginosa E. coli , 54.8% at and 42.9% for P. aeruginosa S. ebony and 42.9% for . Against yeasts and molds LEO has an effectiveness reaching 53.1% for S. ebony . Against yeasts and molds LEO has anC. albicans effectiveness reaching 53.1% for and 56.6% for S. cerevisiae C. albicans to 44.3% against and 56.6% for A. brasiliensis S. cerevisiae and F. moniliforme to 44.3% against of 49.2%. A. brasiliensis and F. moniliforme of 49.2%. Most effective inhibition efficiency against the tested bacteria, yeasts, and fungal strains from the chitosan coated samples was calculated for the 2 g/m2 (BP/Ch 2) paper samples with an average of 79%. At BP/Ch 1 and BP/Ch 0.5 the effectiveness was 72.38% and 54.67%, respectively. Coating layer of 2 g/m2 inhibit the Gram-positive bac-teria S. aureus and B. cereus and the Gram-negative bacterium E. coli, the yeasts C. albicans and S. cerevisiae, 4 456 Most effective inhibition efficiency 29–30 May 2025, Ljubljana, Slovenia against the tested bacteria, yeasts, and fungal strains from the chitosan coated samples was calculated for the 2 g/m2 (BP/Ch 2) paper samples with an average of 79%. At BP/Ch 1 and BP/Ch 0.5 the effectiveness was 72.38% and 54.67%, respectively. Coating layer Gram-negative bacteria –90%. It has a weaker effectiveness against the Gram-negative bacteria P. aeruginosa (56.3%) P. aeruginosa (56.3%) and S. ebony (48.6%). The efficiency of the 1 g/m 2 coating is lower and S. ebony (48.6%). The efficiency of the 1 g/m 2 coating is lower against the Gram-negative bacteria against the Gram-negative bacteria P. aeruginosa (54.8%) and S. ebony (47.4%), but is found to be about 80% P. aeruginosa (54.8%) and S. ebony (47.4%), but is found to be about 80% effective against the Gram-effective against the Gram-positive bacteria S. aureus , B. cereus , the Gram-negative bacterium E. coli , the yeasts positive bacteria E. coli, the yeasts C. albicans and S. cerevisiae, and the fungal strains A. brasiliensis and F. moniliforme and the fungal strains A. brasiliensis and F. moniliforme by 80–90%. It has a weaker effectiveness against the by 80 of 2 g/m2 inhibit the Gram-positive bacteria S. aureus and B. cereus and the Gram-negative bacterium cerevisiae and the fungal strain A. brasiliensis and F. moniliforme. As lower the chitosan coating is applied (BP/Ch 0.5), the lowest inhibition efficiency is observed. applied (BP/Ch 0.5), the lowest inhibition efficiency is observed. C. albicans, S. aureus, B. cereus, the Gram-negative bacterium E. coli, the yeasts C. albicans, S. S. cerevisiae and the fungal strain A. brasiliensis and F. moniliforme. As lower the chitosan coating is Table 3: Inhibition efficiency of the chitosan coated paper samples against Gram-positive and Gram-negative Table 3: Inhibition efficiency of the chitosan coated paper samples against Gram-positive and Gram-bacteria, yeast and fungal strain. negative bacteria, yeast and fungal strain. Sample Inhibition efficiency of chitosan coating (%) Tested microorganisms BP/Ch 0.5 BP/Ch 1 BP/Ch 2 Gram-Staphylococcus aureus A 76.4 78.5 86.5 positive ATCC 6538 B bacteria Bacillus cereus АТСС 10876 31.2 79.5 88.2 C Es с herichia coli ATCC 8739 51.8 73.7 89.5 Gram-Pseudomonas aeruginosa D 32.3 54.8 56.3 negative ATCC 9027 bacteria Salmonella abony NTCC E 20.2 47.4 48.6 6017 F Candida albicans ATCC 62.9 81.7 82.6 10231 Yeast Saccharomyces cerevisiae G 76.6 82.8 89.9 ATCC 2601 H Aspergillus brasiliensis Fungal 65.9 70.1 82.4 ATCC 16404 strain I Fusarium moniliforme 74.7 82.9 87.1 4. CONCLUSIONS Colloidal silver solution containing silver nanoparticles suspended in a liquid base on consumption of 3 4. CONCLUSIONS Colloidal silver solution containing silver nanoparticles suspended in a liquid base on consumption of 3 mL/20cm mL/20cm 2 paper treatment inhibited the growth of the Gram-positive bacterium S. aureus with 81.6% 2 paper treatment inhibited the growth of the Gram-positive bacterium and the Gram-negative bacterium E. coli with 75.8%. Packaging paper treatment with lavender essential S. aureus with 81.6% and the Gram-negative bacterium oil is characterized with sufficient inhibition efficiency E. coli with 75.8%. Packaging paper treatment with lavender essential oil is characterized with sufficient reaching 67.2% for Gram-negative bacterium E. treated paper is more pronounced than the antibacterial one. Most effective inhibition efficiency against the tested Most effective inhibition efficiency against the tested bacteria, yeasts, and fungal strains from the 2 bacteria, yeasts, and fungal strains from the chitosan coated samples was calculated for the 2 g/m inhibition efficiency reaching 67.2% for coli . The antifungal effect of the obtained treated paper is more pronounced than the antibacterial one. Gram-negative bacterium E. coli . The antifungal effect of the obtained chitosan coated samples was calculated for the 2 g/m (BP/Ch 2) paper samples with an average 2 of (BP/Ch 2) 79%. At BP/Ch 1 and BP/Ch 0.5 the effectiveness was 72.38% and 54.67%, respectively. The practical paper samples with an average of 79%. At BP/Ch 1 and BP/Ch 0.5 the effectiveness was 72.38% and 54.67%, aspect of this research highlights the potential of various treatments for enhancing the antimicrobial respectively. The practical aspect of this research highlights the potential of various treatments for enhancing inhibit the growth of both Gram-positive and Gram-negative bacteria, making it a promising treatment cantly inhibit the growth of both Gram-positive and Gram-negative bacteria, making it a promising treatment for for antimicrobial packaging. Additionally, packaging paper treated with lavender essential oil properties of packaging materials. Colloidal silver solution, with silver nanoparticles, can significantly the antimicrobial properties of packaging materials. Colloidal silver solution, with silver nanoparticles, can signifi- demonstrates notable effectiveness against E. coli, while chitosan-coated paper samples show a high effectiveness against E. coli, while chitosan-coated paper samples show a high level of inhibition, particularly at a antimicrobial packaging. Additionally, packaging paper treated with lavender essential oil demonstrates notable level of inhibition, particularly at a concentration of 2 g/m2. This suggests that incorporating silver concentration of 2 g/m 2 . This suggests that incorporating silver nanoparticles, essential oils, or chitosan coatings nanoparticles, essential oils, or chitosan coatings into packaging materials could be an effective strategy into packaging materials could be an effective strategy for improving food safety and extending shelf life. for improving food safety and extending shelf life. 5. REFERENCES De Matteis, V., Cascione, M., Costa, D., Martano, S., Manno, D., Cannavale, A., Mazzotta, S., Paladini, F., Martino, M., Rinaldi, R. 2023. “Aloe Vera Silver Nanoparticles Addition in Chitosan Films: 5 457 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES De Matteis, V., Cascione, M., Costa, D., Martano, S., Manno, D., Cannavale, A., Mazzotta, S., Paladini, F., Martino, M., Rinaldi, R. 2023. “Aloe Vera Silver Nanoparticles Addition in Chitosan Films: Improvement of Physicochemical Properties for Eco-Friendly Food Packaging Material” J. Mater. Res. Technol. 24: 1015–1033. Kumar, S., Basumatary, I.B., Sudhani, H.P.K., Bajpai, V.K., Chen, L., Shukla, S., Mukherjee, A. 2021. “Plant Extract Mediated Silver Nanoparticles and Their Applications as Antimicrobials and in Sustainable Food Packaging: A State-of-the-Art Review Trends” Food Sci. Technol. 112: 651–666. Kuorwel, K.K., Cran, M.J., Sonneveld, K., Miltz, J., Bigger, S.W. 2011. “Essential Oils and Their Principal Constituents as Antimi-crobial Agents for Synthetic Packaging Films” Journal of Food Science 76 (9): R164–R177. Predoi, D., Iconaru, S., Buton, N., Badea, M., Marutescu, L. 2018. “Antimicrobial Activity of New Materials Based on Lavender and Basil Essential Oils and Hydroxyapatite” Nanomaterials 8 (5): 291. Todorova, D.; Yavorov, N.; Lasheva, V.; Damyanova, S.; Kostova. 2023. “Lavender Essential Oil as Antibacterial Treatment for Packaging Paper” Coatings. 13: 32. Zhang, W., Hadidi, M., Karaca, A.C., Hedayati, S., Tarahi, M., Assadpour, E., Jafari, S.M. 2023. “Chitosan-Grafted Phenolic Acids as an Efficient Biopolymer for Food Packaging Films/Coatings” Carbohydr. Polym. 314: 120901. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-authors: Urška Vrabič Brodnjak Dimitrina Todorova Faculty of Natural Sciences Technology and Metallurgy 8 Kl. Ohridski Blvd. University of Ljubljana University of Chemical and Engineering 1797, Sofia, Bulgaria Aškerčeva 12 todorova.dimitrina@uctm.edu 1000 Ljubljana, Slovenia urska.vrabic@ntf.uni-lj.si Nikolay Yavorov University of Chemical Technology and Metallurgy 8 Kl. Ohridski Blvd. 1797, Sofia, Bulgaria nyavorof@uctm.edu 458 2D AND 3D PRINTING 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION ENHANCING PRINTABILITY AND RUNNABILITY RELATED FACTORS IN VARIOUS INKJET PRINT HEADS WHILE PRINTED ON VARIOUS PAPER SUBSTRATES Sandeep Boora1 and Anjan Kumar Baral2 1 Central University of Haryana, Mahendergarh, India 2 Guru Jambheshwar University of Science Technology, India Abstract: This study is aimed to investigate the printability and runnability aspects of various grades of printing paper and the impact of their surface properties on print quality in different inkjet technologies (DOD, CIJ). Various print-related parameters such as; colour cast, colour non-uniformity, print sharpness, graininess, hickeys, moire, banding, dimensional stability, print consistency, and runnability were measured using the standard observer method on a 5-point Likert scale. Twenty observers visually assessed the print quality for each parameter, and the data was statistically analysed using the TOPSIS method. Scanning Electron Microscope (SEM) test of the selected papers was performed at 1000X magnification for analysis of paper surface characteristics. It was found that excellent print consistency and colour uniformity were observed on all of the selected papers. Surface pro-perties of paper, such as porosity and roughness, played a crucial role in graininess, consistency, and sharpness of prints, with gloss papers exhibiting favourable results. The results of the study clearly demonstrated that an explicit correlation could be established between porosity, cobb values and sharpness of print. Keywords: Inkjet Printing, Drop-On-Demand Inkjet, Continuous Inkjet, Banding, Print consistency, Print Sharp-ness. 1. INTRODUCTION Inkjet printing is a versatile non-impact printing method known for its high-resolution output and precision. The fundamental principle of inkjet printing involves the deposition of minuscule ink droplets onto a substrate to form images or text. These droplets, which can be as small as a few picoliters, are controlled and directed through nozzles using advanced hardware and software systems, enabling excellent colour gamut and image sharpness (Hudd, 2010). For optimal results, the substrate’s morphological properties (porosity, roughness, and smoothne-ss) and chemical properties (pH and surface energy) must be compatible with the ink. Incompatibilities can cause defects such as absorption issues, uneven ink spreading, adhesion, wicking, improper wetting or drying (Rosalen & Backhaus, 2019). Inkjet printing can be mainly categorized into two types: 1) Continuous Inkjet (CIJ) and 2) Drop-on-Demand (DOD). DOD is further categorized into Piezoelectric Inkjet (PIJ) and Thermal Inkjet (TIJ) (Shah et al., 2021). The CIJ technology utilizes an electric field for the continuous production and deflection of electrically charged droplets to create an image on the substrate. A major drawback of CIJ is the tendency of ink to bleed and blur, especially on porous surfaces (Ha et al., 2019). The size and frequency of the droplets are affected by different factors, such as the surface tension of ink, the nozzle orifice, and pressure applied (Askeland, 2015). In contrast, in DOD technology ink droplets are ejected only when they are required, which significantly reduces ink wastage while offering high-resolution printing. In TIJ technology, the drops are generated and jetted on to substrate at a very high speed by heating the ink using voltage control. After heating, the ink produces a drive bubble (vapour of ink) where after a certain time the drive bubble expands and jets the ink droplet through the orifice of the printhead. Very small droplets of ink are generated (Kipphan,2001; Hoath, 2016; Askeland 2015). In PIJ technology, a special type of piezoelectric crystal/disk is used that generates a pressure which ejects the 460 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia ink droplet from the orifice of the printhead. This technology makes use of the piezo ceramic property to deform under voltage variation. The pressure in the ink chamber is controlled using electric voltage which assists the ink droplet to eject onto the substrate. The size of the droplet is controlled very precisely by means of the electrical onto the substrate. The size of the droplet is controlled very precisely by means of the electrical pulse pulse (Kippan 2001; Askeland 2015; Kraushaar, 2018). (Kippan 2001; Askeland 2015; Kraushaar, 2018). InkJet Printing Continuous Drop On Demand Inkjet [CIJ] [DOD] Thermal Piezoelectric Figure 1: Classification of Inkjet Printing Figure 1: Classification of Inkjet Printing Printability and runnability are two important aspects to measure print quality in inkjet printing. Printability Printability and runnability are two important aspects to measure print quality in inkjet printing. Printability depends depends on various paper-related factors during printing and also depends on the inherent quality of the on various paper-related factors during printing and also depends on the inherent quality of the paper, while run paper, while runnability refers to the smooth passage of paper through the printing machine. Both, -nability refers to the smooth passage of paper through the printing machine. Both, impact print quality and cost. impact print quality and cost. Inkjet printing with its ability to use thin liquid inks, faces significant Inkjet printing with its ability to use thin liquid inks, faces significant challenge in achieving high print quality due challenge in achieving high print quality due to the influence of substrates wetting characteristics on final to the influence of substrates wetting characteristics on final dot size. Effective selection of substrate, tackling dot dot size. Effective selection of substrate, tackling dot spread and adressing processing needs helps to spread and adressing processing needs helps to ensure, both printability and runnability in inkjet printing process. ensure, both printability and runnability in inkjet printing process. Coated papers with enhanced to uncoated papers (Pedersen et al., 2010; Boora & Baral, 2023). Print quality depends on paper and ink proper (Pedersen et al., 2010; Boora & Baral, 2023). Print quality depends on paper and ink properties, print -head specifications, and colour management software used. Proper ink retention on the surface of Coated papers with enhanced smoothness, gloss and brightness typically yield superior print quality as compared smoothness, gloss and brightness typically yield superior print quality as compared to uncoated papers strate is crucial for achieving desired density as well as colour saturation on final print (Svanholm & Ström, 2004). substrate is crucial for achieving desired density as well as colour saturation on final print (Svanholm & ties, print head specifications, and colour management software used. Proper ink retention on the surface of sub- Ström, 2004). Several studies have been conducted to investigate the factors influencing print quality in inkjet printing. Rese-Several studies have been conducted to investigate the factors influencing print quality in inkjet printing. archers including Bartleson (1982), Petersson (2005) and Pedersen et al. (2010, 2011) examined the perceived Researchers including Bartleson (1982), Petersson (2005) and Pedersen et al. (2010, 2011) examined image quality by human observers through psychophysical experiments based on the extensive research on the the perceived image quality by human observers through psychophysical experiments based on the existing quality attributes including lightness, blur, resolution, colour reproduction, tone reproduction, colour cast, extensive research on the existing quality attributes including lightness, blur, resolution, colour sharpness, print consistency, graininess, gloss, mottle, and roughness. Finally, to represent overall quality the reproduction, tone reproduction, colour cast, sharpness, print consistency, graininess, gloss, mottle, and attributes were reduced to six comprehensive attributes; the colour, lightness, contrast, sharpness, artefacts and roughness. Finally, to represent overall quality the attributes were reduced to six comprehensive physical quality attributes. The properties of ink (viscosity, surface tension, density, drop volume) and printed sur-attributes; the colour, lightness, contrast, sharpness, artefacts and physical quality attributes. The face (surface energy) impact droplet setting in inkjet printing. In capillary imbibition, properties such as ink contact properties of ink (viscosity, surface tension, density, drop volume) and printed surface (surface energy) angle, pore size/distribution, connectivity, permeability, and tortuosity within the porous layer are crucial (Kettle et impact droplet setting in inkjet printing. In capillary imbibition, properties such as ink contact angle, pore al.,2010). Additionally, Gast and Tse (2001) conducted a subjective survey on print quality, specifically focusing on size/distribution, connectivity, permeability, and tortuosity within the porous layer are crucial (Kettle et noise, banding, blur, colour rendition and tone reproduction, which revealed preferences and cultural differences al.,2010). Additionally, Gast and Tse (2001) conducted a subjective survey on print quality, specifically in colour rendition. Evaluation of print quality can be done through both; human perception assessment, where focusing on noise, banding, blur, colour rendition and tone reproduction, which revealed preferences the human visual system plays a key role in subjective judgment, and the use of measurement instruments for and cultural differences in colour rendition. Evaluation of print quality can be done through both; human perception assessment, where the human visual system plays a key role in subjective judgment, and objective assessment (Gast & Tse, 2001). the use of measurement instruments for objective assessment (Gast & Tse, 2001). 2. MATERIALS AND METHODS 2. MATERIALS AND METHODS For this study, three categories of paper, comprising uncoated (90 g/m2), gloss coated (88 g/m2), and matt coat-For this study, three categories of paper, comprising uncoated (90 g/m2), gloss coated (88 g/m2), and ed (90 g/m2), were selected for printing using continuous (CIJ), piezo (PIJ), and thermal (TIJ) inkjet printheads. matt coated (90 g/m2), were selected for printing using continuous (CIJ), piezo (PIJ), and thermal (TIJ) The selection of papers was based on three broad categories commonly utilized in inkjet presses. The surface inkjet printheads. The selection of papers was based on three broad categories commonly utilized in properties of the papers, including thickness, porosity, burst factor, roughness, gloss, brightness, Cobb value, inkjet presses. The surface properties of the papers, including thickness, porosity, burst factor, and opacity, were measured in a standardized paper-testing laboratory. A Scanning Electron Microscope (SEM) roughness, gloss, brightness, Cobb value, and opacity, were measured in a standardized paper-testing analysis of the selected papers was conducted at the Central Instrumentation Lab (CIL), GJUS&T, Hissar to de-laboratory. A Scanning Electron Microscope (SEM) analysis of the selected papers was conducted at 461 2 29–30 May 2025, Ljubljana, Slovenia termine the surface properties of the papers. Figure 2 illustrates SEM images of the selected paper samples at 1000X magnification. a. Uncoated Paper b. Matt Coated Paper c. Gloss Coated Paper Figure 2. SEM images of Paper Types Used for Printing at 1000X 2.1 Preparation of Test Chart: A test master was designed consisting of all the elements, which were instrumental in the measurement of various print quality factors. The elements incorporated in the test chart are; • Four-colour black, micro points, fine lines, ISO images (ISO 400, ISO 800, ISO 102400). • University logo. • Colour control strips having solids to measure Solid Ink Density (SID), grey scales, and 40%-80% tints to measure Tone Value Increase (TVI). 2.2 Printing Process: Printing was performed on UC, MC, and GC paper using three types of calibrated inkjet printing machines under controlled press-room conditions, equipped with the following printheads; • Continuous Inkjet (CIJ): Stream Jet. • Piezoelectric Inkjet (PIJ): Oce Canon (Kyocera KJ4B). • Thermal Inkjet (TIJ): Hewlett Packard (A53 HDNA). Each paper sample was printed on an 11″ × 17″ sheet. 2.3 Evaluation of Print Quality: The print quality was assessed on a Likert scale from 1 (lowest) to 5 (highest). The evaluation was performed by: • Standard Observers Method: Twenty individuals who have prior knowledge of printing, were selected using the Farnsworth-Munsell (FM) hue test. Factors such as colour cast, colour non-uniformity, graininess, moiré, hickeys, sharpness, consistency, and banding was assesed by the standard observers. • Viewing Conditions: Standard conditions with a D-50 light source. 2.4 Data Analysis To analyze the data: o MATLAB™ 2023 was used for numerical simulations to evaluate print-related parameters. o TOPSIS Analysis (Technique for Order Preference by Similarity to an Ideal Solution) was employed to determine the performance of inkjet heads and paper combinations. 462 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS WITH DISCUSSION The print performance of different paper substrates i.e. UC, MC and GC printed using three inkjet technologies i.e. M-I, M-II, and M-III was evaluated across key print quality metrics. The data collected through standard observer assessments was subjected to statistical analysis to indicate trends in printability and runnability. 3.1 Analysis of Print-Related Parameters Banding and Colour Cast: Banding and colour cast values were consistently low across all selected machines, with the highest observed value being 1.56 for GC on M-II. MC exhibited better performance than UC and GC with minimal banding and colour cast values across all machines, demonstrating its balanced surface properties. In contrast, UC showed slightly higher banding and colour cast values due to its rougher surface and higher porosity. Graininess and Print Sharpness: MC and GC performed better than UC in terms of graininess and sharpness. The average values of sharpness for MC and GC ranged between 4.34 and 4.81, while sharpness values were moderate (3.40–3.43) for UC. Graininess was significantly higher on UC (2.19–2.23), conforming to its SEM results that clearly showed greater surface irregularities compared to coated substrates. Table 1 represents the average values of different print related factors as assessed by the standard observers. The same was used as Decision Making Matrix for TOPSIS analysis. Table 1: Average values as assessed by standard observes and Decision Making Matrix for TOPSIS M-I M-II M-III Banding Banding Banding Graininess Graininess Graininess Colour Cast Colour Cast Colour Cast Print Sharpness Print Sharpness Print Sharpness Print consistency Print Consistency Print consistency Colour non-uniformity Colour non-uniformity Colour non-uniformity UC 3.4 3.4 1.54 1.37 1.06 2.21 4.71 3.43 1.32 1.38 1.04 2.23 4.12 1.52 1.45 1.05 2.19 4.12 MC 1.22 1.54 1.24 1.51 4.75 4.37 1.24 1.50 1.05 1.56 4.77 4.34 1.19 1.53 1.16 1.49 4.78 4.26 GC 1.4 1.22 1.35 1.39 4.16 4.82 1.56 1.20 1.05 1.42 4.93 4.81 1.06 1.20 1.66 1.47 4.77 4.76 Colour Non-Uniformity and Print Consistency: Across all machines, colour non-uniformity values were close to the minimum, whereas, print consistency values were close to maximum, indicating excellent consistency in colour reproduction. These attributes exhibited negligible variation across the selected substrates and machines, reflecting the robustness of the inkjet systems used. 463 29–30 May 2025, Ljubljana, Slovenia 3.23 Machine-Specific Performance The evaluation of machine-specific performance revealed the following results as displayed in Table 2, where, Ri is the closeness coefficient between various machines and ideal solution. Table 2: Closeness co-efficient and rank for the proposed system in relation to machines UC Overall Performance MC GC (Machine) R R R R Rank i i i i M-I 2 3 2 0.4569 2 M-II 1 1 1 0.623 1 M-III 3 2 3 0.3779 3 CIJ (M-I): Delivered consistent performance with low banding and colour cast values, particularly on MC and GC. However, sharpness and graininess values for UC were moderate due to its surface roughness. PIJ (M-II): Achieved the highest performance, with superior sharpness (4.81 on GC) and high print consistency (4.93). Its precise droplet control enabled better print quality across all substrates. TIJ (M-III): Demonstrated results similar to CIJ, performing well on MC and GC but showing limitations on UC due to substrate absorption and roughness characteristics. 3.3 Substrate-Specific Performance The performance of the paper substrates varied significantly. Table 3 represents the substrate-specific perfor-mance through TOPSIS analysis: Table 3: Closeness co-efficient and rank for the proposed system in relation to papers M-I Overall Performance M-II M-III (Paper) R Rank i R i R i R i UC 3 3 2 0.3584 3 MC 2 2 1 0.802 1 GC 1 1 3 0.6415 2 Gloss Coated Paper (GC): Consistently ranked as the best-performing substrate for sharpness and print consis-tency. It achieved high scores across all machines, particularly in M-I and M-II. Matt Coated Paper (MC): Showed balanced performance, excelling in both printability and runnability. It exhibited minimal banding and colour cast values while maintaining high sharpness and consistency. Uncoated Paper (UC): While satisfactory for basic applications, UC showed limitations in sharpness and graini-ness, with performance significantly influenced by its rough surface and high porosity. 464 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS The study focused on various critical factors that influence print quality and consistency of inkjet printing on di-fferent paper types. The results of the study demonstrated that GC exhibited minimal colour cast and superior colour uniformity, followed by UC and MC. Paper quality directly affected colour consistency due to varying ink absorption. Banding, chracterized by printed output lines, was influenced by paper type and inkjet technology. Surface properties of paper, such as porosity and roughness, played a crucial role in graininess, consistency, and sharpness of prints, with gloss papers exhibiting favourable results. The results of the study clearly demonstrate that an explicit correlation could be established between porosity, cobb values and sharpness of print. The greater the porosity of the paper the lower are the sharpness values. It is evident from the results the porosity values of UC being the maximum (140.0) in comparison to MC and GC which is 127.8 and 108, respectively, results in lower sharpness values of 3.43 for UC and relatively higher values of 4.37 and 4.82 on MC and GC, respectively printed under M-I. The same is true for M-II and M-III as well. Coated papers generally exhibit better performance than uncoated ones in terms of printability, with specific paper attributes like porosity, roughness, brightness, and gloss exerting substantial influence on print quality. The high surface roughness values of UC (14.9) in comparison to MC (11.9) and GC (10.0) resulted in the relatively higher values of graininess on UC. The TOPSIS results eluci-dated that GC performed better on M-I and M-II, while MC exhibited overall better printability and runnability. In terms of machine performance, M-II exhibited excellent printability and runnability in comparison to M-I and M-III. 5. REFERENCES Askeland, R. A. (2015). Inkjet Print Engines. Handbook of Digital Imaging, 1-31. Bartleson, C. J. The Combined Influence of Sharpness and Graininess On the Quality of Colour Prints. The Journal of Photographic Science, 30(2), 33-38 (1982). Boora, S., & Baral, A. K. (2023). Critical Analysis of Printability of Different Types of Paper Substrates while printed with Piezoelectric and Thermal Inkjet Presses. European Chemical Bulletin Gast, G.; Tse, M. K.; A Report On a Subjective Print Quality Survey Conducted at Nip16. In Nip & Digital Fabrication Conference (Vol. 2001, No. 2, Pp. 723-727). Society for Imaging Science and Technology (2001, January). Ha, Y. B., Park, J. Y., & Kim, H. J. (2019). Influence of the Physical Properties of Digital Printing Paper on the Printing Quality. 51(2), 108-120. Hoath, S. D. (Ed.). (2016). Fundamentals of Inkjet Printing: The Science of Inkjet and Droplets. John Wiley & Sons. Hudd, A. (2010). Inkjet Printing Technologies (pp. 3-18). World Scientific Publishing, Hackensack, NJ, USA. Kettle, John & Lamminmäki, Taina & Gane, Patrick. (2010). A Review of Modified Surfaces for High Speed Inkjet Coating. Surface and Coatings Technology. 204. 2103-2109. Kipphan, H. (Ed.). (2001). Handbook of Print Media: Technologies and Production Methods. Springer Science & Business Media. Kraushaar. (2018). Process Standard Digital (PSD). Fogra Research Institute for Media Technologies. Pedersen, M., Bonnier, N., Hardeberg, J. Y., & Albregtsen, F. (2010). Attributes of Image Quality for Colour Prints. Journal of Electronic Imaging, 19(1), 011016-011016. Pedersen, M.; Zheng, Y.; Hardeberg, J. Y. (2011, May).; Evaluation of Image Quality Metrics for Color Prints. In Scandinavian Conference On Image Analysis (PP. 317-326). Springer, Berlin, Heidelberg Petersson, J. A. (2005).; Review of Perceptual Image Quality Rosalen, S., & Backhaus, J. (2023). Comparing Quality Attributes of Coated Cardboards for Inkjet Printing by using Different Methods. Journal of Print and Media Technology Research, 8(4), 211–226. Shah, M. A., Lee, D. G., Lee, B. Y., & Hur, S.; Classifications and Applications of Inkjet Printing Technology: A Review. IEEE Access, 9, 140079-140102 (2021). Svanholm, E., & Ström, G. (2004). Influence of polyvinyl alcohol on inkjet printability. 465 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Sandeep Boora Anjan Kumar Baral Central University of Haryana Guru Jambheshwar Faculty, Department of Printing University of Science & Technology and Packaging Technology Faculty, Department of Printing Tech- Central University of Haryana, Jant-Pali nology Mahendergarh Haryana Pin: 123031 125001, Hisar, Haryana +91-8168176815 +91-9416061528 anjan_baral2222@yahoo.co.in sboora1@cuh.ac.in 466 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION INNOVATIVE APPROACHES TO COLOR REPRODUCTION ON 3D PRINTED FLAT AND LOW-RELIEF SURFACES Jon Brce1, Matej Pivar1 and Deja Muck1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: This study investigates color printing techniques for 3D-printed objects and their potential in 4D printing applications. It compares direct UV inkjet printing with indirect electrophotographic (EP) heat transfer, highlighting key differences in color reproduction. UV inkjet printing provides a wider color gamut, particularly in blue and green tones, while EP heat transfer minimizes dot gain and deformation. Both methods exhibit strong adhes-ion, though surface texture influences print sharpness. For 4D printing, UV inkjet printing proves superior due to its ability to print on both sides and on low-relief surfaces, whereas EP heat transfer is limited to single-sided applications on flat surfaces. The integration of 2D printing into 4D printing enhances customization, aesthetics, and interactivity. Additionally, flat 3D-printed geometries improve storage, transport, and material efficiency. The study also presents a practical example: a UV inkjet-printed mobile phone stand that undergoes a complex shape transformation upon thermal activation. Results confirm that UV inkjet printing ensures high-quality prints without visible irregularities, making it a promising method for 4D printing. Keywords: 4D printing, 3D printing, UV inkjet, Electrophotography, colour reproduction 1. INTRODUCTION The origins of 3D printing trace back to Slovenian professor Dr. Igor Grabec, who pre-patented a three-dimen-sional recorder in 1969 (Muck, 2015). However, it was not until the 1980s that 3D printing technologies became commercially viable. Charles Hull pioneered stereolithography (SLA) in 1983, and Scott Crump developed the widely used Fused Deposition Modeling (FDM) for thermoplastics in 1988 (Abar, 2024). Over the last decade, advancements in 3D printing have enabled the fabrication of highly complex structures with increasing precision (Ngo et al., 2018; Jandyal, 2022). A significant area of research within 3D printing is multicolor and full-color printing (Formlabs, 2024). Achieving accurate and consistent color reproduction on 3D surfaces presents numerous challenges, influenced by factors such as printing technology, material properties, and surface characteristics (Jiangping, 2021; Singh, 2017; Taufik, 2017; Tan, 2020; Zang, 2012). These challenges have led to the exploration of new materials, including smart and programmable materials, which have contributed to the evolution of 4D printing (Chen, 2024). 4D printing, which incorporates time as the fourth dimension, was first conceptualized by Skylar Tibbits in 2013, followed by the establishment of the Self-Assembly Lab at MIT in 2014. This technology enables 3D-printed ob-jects to transform over time when exposed to environmental stimuli (Pivar, 2022; Pivar, 2024). The integration of color printing into 4D printing remains an emerging field, requiring further investigation into how different color application methods interact with dynamic material transformations. This study investigates two distinct methods of color reproduction on 3D-printed samples, particularly their practi-cal applications and potential integration into 4D printing. The methods analyzed are direct UV-inkjet printing and indirect thermal transfer of electrophotographic (EP) toner. The research aimed to evaluate print quality, adhesion, and the achievable color gamut of each method, as well as their suitability for 4D printing applications. For this study, white PLA filaments were used to fabricate flat and low-relief (bas-relief) samples using an FDM-ba-sed ZMorph VX 3D printer. Two color application methods were employed: direct UV-inkjet printing and indirect thermal transfer of EP toner. The comparison of these methods revealed distinct advantages and limitations. 467 29–30 May 2025, Ljubljana, Slovenia A crucial aspect of the research extended these methods to programmable 4D printing, where flat 3D-printed structures transform into complex shapes under external stimuli, such as heat. 2. EXPERIMENTAL 2.1 3D printing process 3D printing of 70 × 130 mm samples with a thickness of 0.3 mm was carried out using a ZMorph VX 3D printer (ZMorph S.A., Poland) equipped with a heated build plate. The samples were printed from white PLA filament sourced from Plastika Trček d.o.o. (Slovenia, Ljubljana). White PLA was selected to achieve a wider color gamut in printed reproductions. The PLA was printed directly onto temperature-resistant Avery Zweckform 3560 polyester film, obtained from CCL Industries Inc. (Canada, Toronto). Two variations were tested: one with an unprinted polyester film and another pre-printed with a color test image. The 3D printing process was optimized using a 0.4 mm nozzle diameter, an extrusion temperature of 215°C, and a build plate temperature of 30°C. The first layer was printed at 0.1 mm, while subsequent layers were set to 0.2 mm. A rectilinear infill pattern with a 0° orientation ensured structural consistency. Printing parameters were carefully adjusted to ensure strong adhesion between the PLA and polyester film, as well as to achieve a smooth surface, which is crucial for optimal printability. These factors also played a key role in facilitating effective toner transfer from the polyester film to the PLA material. In addition to samples with flat surfaces, samples with low-relief surfaces were also printed. To generate these low-relief textures, the Fuzzyfictator plugin in Slicer software was utilized. This approach enabled an assessment of how the color printing process performs on slightly textured or rough surfaces, providing valuable insights into print quality, adhesion, and color accuracy on non-flat geometries. 2.2 Colour printing process In the first step, color test images were printed onto the 3D-printed samples using two methods. The indirect printing process involved heat transfer of EP toner from polyester film during the 3D printing process, while the direct printing process applied UV inks onto the flat geometry of the 3D-printed samples. Both methods utilized digital printing techniques and identical test images. For indirect printing, a Xerox Versant 280 EP digital printer (Xerox, U.S.) was used to print test images onto polyester film. For direct printing, an Apex UV6090 UV LED inkjet flatbed printer (Apex, China) with Nazdar 260 UV LED inks was employed. The test images were designed to evaluate key print quality attributes using validated methods. They included color patches for spectrophotometric measurements, optical density, and tonal value assessments, as well as geometric quality elements and ink adhesion tests. Five samples were printed for each method. In the second step, the same color printing processes were applied to low-relief, textured surfaces, following the same methodology as in the first step. 2.3 Printing evaluation Densitometric and spectrophotometric measurements were performed using an X-Rite Exact spectrodensitome-ter under D50 illumination, with a 2° standard observer, 45:0 measurement geometry, and white backing. Optical density, tonal values, and CIELAB color values were determined for both printing methods. Adhesion of UV ink and EP toner to PLA was assessed using the cross-cut method with a Byko-Cut device (BYK-Gardner GmbH, Germany). Cuts were made at a 45° angle to the filament direction and inspected with a Dino-Lite AM4113ZT digital microscope (AnMo Electronics Corporation, Taiwan). Adhesion quality was evaluated based on the ISO 2409 classification. Geometric irregularities of printed elements were analyzed using ImageJ 1.54 (open-source software). Images, captured with a Dino-Lite AM4113ZT microscope at 50x magnification, were used to assess edge sharpness and physical gain on 0.3 mm-wide lines, comparing measured areas and perimeters to digital reference values. Dot deformation was evaluated by measuring roundness of 0.4 mm dots, comparing results to an ideal reference value of 1, calculated using equation (1). Roundness = 4 × area/(π × major_axis2) 468 29–30 May 2025, Ljubljana, Slovenia 2.4 Practical example of a smart structure To demonstrate the practical use of programmable 3D structures in everyday life, a smart mobile phone stand was used as an example. This stand transforms from a flat shape into a functional 3D form upon activation. The struc-ture was printed with color graphics on both sides using a UV inkjet printer, enabling double-sided printing, unlike thermal transfer printing, which only allows printing on one side. After printing, the programmable 3D structure was thermally activated in 80°C water, triggering its transformation. The stand was fabricated using a combination of active PLA and passive PRO-PLA thermoplastics. The active sections featured a rectilinear pattern with 99% infill density, while the passive ones had a 30% infill density. Prin-ting parameters were set at 195°C for the nozzle and 30°C for the build plate. With a thickness of 2.4 mm, the stand comprises three active elements and one passive element in the global system. Locally, one active element is printed on the top side, enabling upward bending, while the other two are on the bottom side, also facilitating upward bending. This programmed structure transforms into its final shape upon thermal activation. All active elements were printed with a 0.1 mm layer height and a filament orientation of 0°, with varying lengths to achieve different bending angles, determined experimentally. A schematic representation of the programmable 3D structure is shown in Figure 1. Figure 1: Schematic representation of the flat geometry of a programmable 3D structure. 3. RESULTS WITH DISCUSSION 3.1 Densitometric analysis Table 1 presents the optical density measurements of solid tone (100% TV) process colors. Heat transfer printing generally shows higher optical density values, except for cyan, which is higher with UV inkjet printing. The highest optical density is observed for black in heat transfer printing, indicating a greater dynamic range compared to UV inkjet printing. Standard deviations confirm stable ink transfer in both methods, suggesting that the surface pro-perties of the 3D-printed samples and printing parameters did not negatively impact ink performance. 469 29–30 May 2025, Ljubljana, Slovenia Table 1: Average values and standard deviations of the optical density. Optical density [/] Colour UV inkjet Heat transfer (EP) C 2.44 (±0.024) 2.29 (±0.028) M 1.61 (±0.011) 2.14 (±0.050) Y 1.71 (±0.015) 2.02 (±0.037) K 1.71 (±0.004) 2.54 (±0.034) Figure 2 illustrates the relationship between the reference and measured tone values for all process colors. The study found that dot gain is generally higher in UV inkjet printing, with magenta showing the lowest gain (24.3%). Cyan, yellow, and black range between 31.9% and 34.4% at 50% tonal value. In heat transfer printing, dot gain is lower for all colors except magenta, with values between 25.2% and 28.1% at 50% tonal value. This suggests that heat transfer printing produces sharper details across light, medium, and dark tones. Figure 2: Dependence between the reference value and the measured tonal value for both printing processes. (a) UV inkjet printing and (b) heat transfer (EP) printing. 3.2 Spectrophotometric analysis Based on measured CIELAB values (Table 2), color gamut diagrams were created for both printing processes (Figure 3). A larger gamut indicates better color reproduction. Comparison shows that UV inkjet prints have a slightly larger gamut than EP prints. Detailed analysis reveals that UV inkjet printing enhances magenta, blue, and green tones, while EP printing achieves more saturated yellow tones. 470 29–30 May 2025, Ljubljana, Slovenia Table 2: CIELAB colour values for both printing processes. UV inkjet Heat transfer (EP) Colour L* a* b* L* a* b* C 45.53 –35.86 –49.67 46.88 –32.81 –52.71 M 47.33 74.89 –5.95 41.50 74.17 6.01 Y 85.54 –4.91 90.82 87.18 –8.27 100.25 K 17.80 1.80 5.02 13.52 –0.42 –1.36 R 46.69 66.78 52.36 40.29 70.37 44.71 G 39.80 –78.45 18.23 39.28 –73.18 24.46 B 16.90 23.98 -49.15 14.46 17.51 –38.14 Figure 3: Colour gamut for both printing processes. 3.3 Ink adhesion The optical images of the cross-cut pattern show that the adhesion of the UV ink and the EP toner to the 3D printed samples is very good. The adhesion of the UV ink achieves ISO classification 0 with smooth cut edges and no detached ink. The adhesion of the EP toner achieved ISO classification 1, with slightly damaged chipped edges and up to 5% detached ink. The analysis of the adhesion showed that both printing processes are suitable for printing on the 3D printed PLA material. 3.4 Image analysis Image analysis revealed geometric irregularities in both printing processes, as shown in Figures 4. Dot roundness measurements confirm that UV inkjet printing results in greater deformation, with an average roundness of 0.821 (±0.027), while heat transfer printing achieves a more circular dot shape at 0.975 (±0.012), nearing the ideal value of 1. This deformation in UV printing is attributed to droplet distribution and ink spreading between filament layers. 471 29–30 May 2025, Ljubljana, Slovenia Figure 4: Visual comparison of microscopic images of printed dots with both printing processes: (a) UV inkjet and (b) heat transfer printing. 29–30 May 2025, Ljubljana, Slovenia Line area measurements show a physical increase in both printing processes compared to the ideal reference ting (2.33 ±0.003 mm²). The perimeter of printed lines also increases significantly, indicating poor edge sharpness indicating poor edge sharpness 23.99 ±1.400 mm for UV inkjet and 20.96 ±0.428 mm for heat transfer 23.99 ±1.400 mm for UV inkjet and 20.96 ±0.428 mm for heat transfer (EP). value (2.1 mm²), with UV inkjet printing exhibiting a greater expansion (2.58 ±0.022 mm²) than heat transfer prin- (EP). Edge deformation in UV printing occurs due to ink spreading into filament channels before curing, while in heat Edge deformation in UV printing occurs due to ink spreading into filament channels before curing, while transfer printing, the toner does not fully transfer into these channels, leading to lower edge sharpness. in heat transfer printing, the toner does not fully transfer into these channels, leading to lower edge sharpness. 3.5 Colour printing on low-relief surfaces 3. 5 Colour printing on low-relief surfaces Colo printing on low-relief surfaces revealed that EP toner transfer during 3D printing on rough surfaces was Color printing on low-relief surfaces revealed that EP toner transfer during 3D printing on rough surfaces uneven, resulting in poor print quality (Figure 5 (b)). In contrast, samples printed with a UV inkjet printer exhibited was uneven, resulting in poor print quality (Figure 5 (b)). In contrast, samples printed with a UV inkjet good print quality, with all elements clearly visible (Figure 5 (a)). printer exhibited good print quality, with all elements clearly visible (Figure 5 (a)). (a) UV inkjet; flat (left), low-relief (right) (b) heat transfer (EP); flat (left), low-relief (right) Figure 5: Figure 5: Visual comparison of images of printed test forms on flat (left) and low-relief (right) surfaces Visual comparison of images of printed test forms on flat (left) and low-relief (right) surfaces with both printing with both printing processes: (a) UV inkjet and (b) heat transfer (EP) printing. processes: (a) UV inkjet and (b) heat transfer (EP) printing. 3.6 Practical example of a smart structure 3.6 Practical example of a smart structure A practical example, printed on both sides with color graphics using a UV inkjet printer, showcases the complex A practical example, printed on both sides with color graphics using a UV inkjet printer, showcases the transformation of programmable 3D structures (Figure 6). This structure changes shape out of plane in both complex transformation of programmable 3D structures (Figure 6). This structure changes shape out of upward and downward directions, with varying degrees of transformation (different angles). The deformation is plane in both upward and downward directions, with varying degrees of transformation (different angles). enabled by three active elements of different lengths, printed locally at specific points on the 3D structure. The deformation is enabled by three active elements of different lengths, printed locally at specific points Two active elements, measuring 13.0 mm and 22.5 mm in length and printed on the underside, bend downwards on the 3D structure. Two active elements, measuring 13.0 mm and 22.5 mm in length and printed on the underside, bend at angles of 82° and 145°, respectively. Meanwhile, an active element of 13.0 mm in length, printed on the top downwards at angles of 82° and 145°, respectively. Meanwhile, an active element of 13.0 mm in length, side, bends upwards at 82°. Throughout the transformation, the passive element connecting the active compo-nents remains stable, ensuring dimensional stability during thermal activation and practical use afterward. printed on the top side, bends upwards at 82°. Throughout the transformation, the passive element Results confirm that programmable 3D structures maintain stability for practical applications, and UV inkjet prin connecting the active components remains stable, ensuring dimensional stability during thermal -activation and practical use afterward. ting delivers high-quality prints without visible irregularities. Results confirm that programmable 3D structures maintain stability for practical applications, and UV inkjet printing delivers high-quality prints without visible irregularities. 472 downwards at angles of 82° and 145°, respectively. Meanwhile, an active element of 13.0 mm in length, printed on the top side, bends upwards at 82°. Throughout the transformation, the passive element connecting the active components remains stable, ensuring dimensional stability during thermal activation and practical use afterward. 29–30 May 2025, Ljubljana, Slovenia Results confirm that programmable 3D structures maintain stability for practical applications, and UV inkjet printing delivers high-quality prints without visible irregularities. Figure 6: Smart structure in flat geometry (left) and thermally activated mobile phone stand (right). Figure 6: Smart structure in flat geometry (left) and thermally activated mobile phone stand (right). 4. CONCLUSIONS 6 This research provides valuable insights into color printing techniques for 3D-printed objects, highlighting their potential for 4D printing applications. The comparison of direct UV inkjet printing and indirect electrophotographic printing reveals key differences in color reproduction quality. While electrophotographic heat transfer minimizes dot gain and deformation, UV inkjet printing offers a wider color gamut, particularly in blue and green tones, ma-king it advantageous for specific applications. Both methods demonstrate good adhesion to 3D-printed surfaces, but surface texture impacts print sharpness. For 4D printing, UV inkjet printing is the superior choice, as it allows double-sided printing, whereas heat transfer (EP) printing is limited to one side. The integration of 2D printing into 4D printing represents a significant step forward, enabling personalization, aesthetic enhancements, and interactive functionality. Additionally, the flat ge-ometry of 3D objects optimizes storage, transport, and material efficiency, reducing plastic waste by eliminating the need for support structures. Both direct and indirect color printing techniques can achieve satisfactory print quality on flat surfaces. However, for low-relief textures or double-sided printing, UV inkjet printing remains the only viable option. Selecting the appropriate printing method depends on the specific requirements of the final product. The expansion of research into 4D printing paves the way for groundbreaking innovations, particularly in the use of active elements for dynamic morphing. Future studies should focus on enhancing accuracy and efficiency, un-locking new industrial applications in 3D and 4D printing. 473 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Abar, M. B., Kelly, C., Allen, N. B., Gall, K. 2024. “Historical perspectives on 3D printing.” Clinical Applications of 3D Printing in Foot and Ankle Surgery, Highlander, P. D., 1-16. United States: Elsevier. Barreto dos Santos, B. M., Littlefair, G., Singamneni, S. 2023. “From 3D to 4D printing: A review.” Materials Today: Proceedings. https://doi. org/10.1016/j.matpr.2023.05.707 Chen, J., Virrueta, C., Zhang, S., Mao, C., Wang, J. 2024. 4D printing: “The spotlight for 3D printed smart materials.” Materials Today. https://doi.org/10.1016/j.mattod.2024.06.004 Formlabs. 2024. Guide to Color 3D Printers. Available from: https://formlabs.com/eu/blog/guide-color-3d-printers/ [Accessed 15th September 2024] Jandyal, A., Chaturvedi, I., Wazir, I., Raina, A., Ul Haq, M. F. 2022. 3D printing – A review of processes, materials and applications in Industry 4.0. Sustainable Operations and Computers, 3, 33-42. https://doi.org/10.1016/j.susoc.2021.09.004 Jiangping, Y., Guangxue, C., Hua, L., Hartmut, P., Kaida, X. 2021. Challenges in Color Reproduction on 3D Printed Objects. Materials & Design, 209, 109943. https://doi.org/10.1016/j.matdes.2021.109943 Muck, D., Križanovskij, I. 2015. 3D tisk: Tehnologije 3D-tiska, priprava 3D-modelov za tisk, pojmovnik. Pasadena. Ngo, T., Kashani, A., Imbalzano, G., Nguyen, K., Hui, D. 2018. Additive manufacturing (3D printing): a review of materials, methods, applications and challenges. Composites Part B: Engineering, 143, 172-196. https://doi.org/10.1016/j.compositesb.2018.02.012 Pivar, M., Gregor-Svetec, D., Muck, D. 2022. Effect of Printing Process Parameters on the Shape Transformation Capability of 3D Printed Structures. Polymers, 14, 117. https://doi.org/10.3390/polym14010117 Pivar, M., Vrabič-Brodnjak, U., Leskovšek, M., Gregor-Svetec, D., Muck, D. 2024. Material Compatibility in 4D Printing: Identifying the Optimal Combination for Programmable Multi-Material Structures. Polymers, 16, 2138. https://doi.org/10.3390/polym16152138 Singh, R., Singh, S., Singh, I. P., Fabbrocino, F., Fraternali, F. 2017. Investigation for surface finish improvement of FDM parts by vapor smoothing process. Composites Part B: Engineering, 111, 228-234. https://doi.org/10.1016/j.compositesb.2016.11.062 Tan, L., Zhu, W., Zhou, K. 2020. Recent progress on polymer materials for additive manufacturing. Advanced Functional Materials, 30(43), 22. https://doi.org/10.1002/adfm.202003062 Taufik, M., Jain, P. K. 2017. Laser assisted finishing process for improved surface finish of fused deposition modelled parts. Journal of Manufacturing Processes, 30, 161-177. https://doi.org/10.1016/j.jmapro.2017.09.020 Yang, X., Wei, X. F., Huang, B. Q., Zhang, W. 2012. Study on the Printability of UV-Curable Inkjet Ink on Different Printed Materials. Applied Mechanics and Materials, 262, 324-328. https://doi.org/10.4028/www.scientific.net/AMM.262.324 ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Deja Muck Jon Brce Chair of Information 01/20 03 296 and Graphic Arts Technology jon.brce@ntf.uni-lj.si Faculty of Natural Sciences Matej Pivar and Engineering 01/20 03 273 University of Ljubljana matej.pivar@ntf.uni-lj.si Snežniška 5 1000 Ljubljana 01/20 03 284 deja.muck@ntf.uni-lj.si 474 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION INFLUENCE OF LOW TEMPERATURE ON MECHANICAL STABILITY OF INKJET PRINTS Maša Šraj1, Barbara Blaznik1 and Sabina Bračko1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Inkjet printing technology has become established in many areas due to its accessibility and flexibility. However, the quality and resistance of the print depend on several factors which can affect the product during transport, storage, and use. In the present research, we analysed the influence of low temperature on the mecha-nical durability of prints to demonstrate the conditions of storing food packaging. The resistance to rubbing was determined for inkjet prints that were previously exposed to a constant low temperature for a certain period of time or alternately to room temperature and low temperature. The resistance of prints to mechanical stress was tested in accordance with appropriate standards and the colour differences that appeared on the prints after rubbing were evaluated. The results showed that exposure to low temperatures did not exhibit any serious destructive effect on the mechanical durability of the prints. Keywords: inkjet, printing, low temperature, resistance, durability 1. INTRODUCTION Due to its accessibility and flexibility, inkjet printing has become an established technology in many areas, from document printing to photos and art. However, the print’s quality and resistance depend firstly on the appropriate formulation of the ink and the dyes and pigments used. Special attention must also be paid to the selection of the printing material, since the absorption of the ink and thus the quality of the final print strongly depend on the chemical and surface properties of both ink and the substrate (Magdassi, 2010; Hoath, 2016). The resistance of print is influenced by many interconnected external factors to which the graphic product is exposed during transport, storage and use. In the past, the research was focused mainly on the phenomenon of photodegradation and the destructive influence of light. The light fastness of colourants and colour prints is influenced by several factors, for example by the structure and concentration of the dye or pigment, the degree of aggregation, the size of the pigment particles, the chemical and physical properties of the printing material, the spectral distribution of the radiation of the light source, the composition of the atmosphere, including relative humidity and impurities present in the air (Zollinger, 2003). In the past, research on the photodegradation processes considered the influence of the structure of the ink and printing material as well as numerous factors that contribute to the degradation process, such as heat, moisture, light, impurities, and microorganisms (Venosa, 2011; Pastorelli; 2014; Izdebska, 2016). Many of the processes that accompany the decomposition of organic materials are temperature dependent and research has shown that the decomposition rate is proportional to the increase in temperature (Feller, 1994; Blaznik, 2017). Additionally, the decomposition process is accelerated by moisture; therefore, the cumulative effect of light, heat and moisture is particularly destructive and can significantly shorten the lifespan of a print (Bamfield, 2001; Bevk, 2023; Blaznik, 2022; Wypych, 2008). On the other hand, we noticed no systematic study regarding the durability of prints at lower temperatures in the absence of light. The aim of our research was therefore to examine the influence of low temperature on the mechanical durability of inkjet prints. The resistance to rubbing was determined for the samples that were previously exposed to con-stant low temperature for a certain period of time or alternately to room temperature and low temperature, and the results were compared with the values for samples that were stored at room temperature. The resulting colour differences and the durability of the prints were evaluated based on spectrophotometric analysis and the CIELAB parameters. 475 low temperature, and the results were compared with the values for samples that were stored at room temperature. The resulting colour differences and the durability of the prints were evaluated based on low temperature, and the results were compared with the values for samples that were stored at room spectrophotometric analysis and the CIELAB parameters. 29–30 May 2025, Ljubljana, Slovenia temperature. The resulting colour differences and the durability of the prints were evaluated based on spectrophotometric analysis and the CIELAB parameters. 2. EXPERIMENTAL 2. EXPERIMENTAL 2.1 Preparation of printed samples 2. EXPERIMENTAL 2.1 Preparation of printed samples Prints were prepared with a Canon Image PROGRAF W8400 inkjet printer (Canon, Japan) using paper with a matte coating, with a grammage of G = 180 g/m 2.1 Preparation of printed samples matte coating, with a grammage of G = 180 g/m contained four fields of cyan, magenta, yellow and black (CMYK) with 100% coverage (C100, M100, 2 and CIE whiteness of W = 121.2. The samples contained four Prints were prepared with a Canon Image PROGRAF W8400 inkjet printer (Canon, Japan) using paper Y100, K100) and four fields with 50% coverage (C50, M50, Y50, K50). Prints were prepared with a Canon Image PROGRAF W8400 inkjet printer (Canon, Japan) using paper with a 2 and CIE whiteness of W = 121.2. The samples with 50% coverage (C50, M50, Y50, K50). contained four fields of cyan, magenta, yellow and black (CMYK) with 100% coverage (C100, M100, 2.2 Exposure pf prints to low temperature and temperature changes Y100, K100) and four fields with 50% coverage (C50, M50, Y50, K50). fields of cyan, magenta, yellow and black (CMYK) with 100% coverage (C100, M100, Y100, K100) and four fields with a matte coating, with a grammage of G = 180 g/m 2 and CIE whiteness of W = 121.2. The samples 2.2 Exposure pf prints to low temperature and temperature changes The prints were exposed to different temperatures in the dark during three time intervals: 6, 12 and 18 days re 2.2 Exposure pf prints to low temperature and temperature changes The prints were exposed to different temperatures in the dark during three time intervals: 6, 12 and 18 days respectively at a constant temperature of 6, –12 or 23 °C or alternately at a temperature of 6 °C - spectively at a constant temperature of 6, –12 or 23 °C or alternately at a temperature of 6 °C and 23 °C, with an and 23 °C, with an interval of 24 hours. 2.3 Durability of prints to rubbing days respectively at a constant temperature of 6, –12 or 23 °C or alternately at a temperature of 6 °C 2.3 Durability of prints to rubbing interval of 24 hours. The prints were exposed to different temperatures in the dark during three time intervals: 6, 12 and 18 and 23 °C, with an interval of 24 hours. The durability of prints to rub was tested using the Rub Tester RT-01 (Labthink, USA) in accordance with the ASTM The durability of prints to rub was tested using the Rub Tester RT-01 (Labthink, USA) in accordance with 2.3 Durability of prints to rubbing the ASTM D 5264 – 98 Standard. The print was placed on the lower plate of the apparatus and an D 5264 – 98 Standard. The print was placed on the lower plate of the apparatus and an unprinted piece of the unprinted piece of the same paper was fixed on a counterweight (m = 1.8 kg). Based on previous same paper was fixed on a counterweight (m = 1.8 kg). Based on previous experiments, 200 cycles of passes The durability of prints to rub was tested using the Rub Tester RT-01 (Labthink, USA) in accordance with experiments, 200 cycles of passes were determined for each sample. were determined for each sample. the ASTM D 5264 – 98 Standard. The print was placed on the lower plate of the apparatus and an unprinted piece of the same paper was fixed on a counterweight (m = 1.8 kg). Based on previous 2.4 Colorimetric properties of prints before and after rubbing 2.4 Colorimetric properties of prints before and after rubbing experiments, 200 cycles of passes were determined for each sample. The mechanical resistance to rubbing was evaluated based on the colour differences that appeared on the sam-The mechanical resistance to rubbing was evaluated based on the colour differences that appeared on ples after rubbing and were calculated using the CIELAB equation for colour differences (Equation 1) (Bračko, 2.4 Colorimetric properties of prints before and after rubbing the samples after rubbing and were calculated using the CIELAB equation for colour differences 2022). The CIELAB coordinates of the prints were measured with an Eye-One spectrophotometer (X-Rite, USA) (Equation 1) (Bračko, 2022). The CIELAB coordinates of the prints were measured with an Eye-One in accordance with the ISO 13655 standard. The values were also measured before rubbing on prints that were The mechanical resistance to rubbing was evaluated based on the colour differences that appeared on spectrophotometer (X-Rite, USA) in accordance with the ISO 13655 standard. The values were also kept at room temperature in the dark, and these values were used as a standard in further calculations. The results the samples after rubbing and were calculated using the CIELAB equation for colour differences measured before rubbing on prints that were kept at room temperature in the dark, and these values (Equation 1) (Bračko, 2022). The CIELAB coordinates of the prints were measured with an Eye-One represent the average of five measurements and are shown in Figure 1. were used as a standard in further calculations. The results represent the average of five measurements spectrophotometer (X-Rite, USA) in accordance with the ISO 13655 standard. The values were also and are shown in Figure 1. measured before rubbing on prints that were kept at room temperature in the dark, and these values were used as a standard in further calculations. The results represent the average of five measurements ∗ ∗2 (1) ∗2 ∗2 ∆𝐸𝐸𝐸𝐸 (1) and are shown in Figure 1. 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 = �∆𝐿𝐿𝐿𝐿 + ∆𝑎𝑎𝑎𝑎 + ∆𝑏𝑏𝑏𝑏 2.5 2.5 CIE whiteness and tint of whiteness after exposure of paper to temperature changes ∗ ∆𝐸𝐸𝐸𝐸 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 = �∆𝐿𝐿𝐿𝐿 ∗2 + ∆𝑎𝑎𝑎𝑎 ∗2 + ∆𝑏𝑏𝑏𝑏 ∗2 (1) CIE whiteness and tint of whiteness after exposure of paper to temperature changes CIE whiteness, W, and tint of whiteness, T w , (Equations 2–3 ) (Bračko, 2022) of paper samples after 2.5 CIE whiteness and tint of whiteness after exposure of paper to temperature changes CIE whiteness, W, and tint of whiteness, T exposure to low temperatures for 6, 12, and 18 days, respectively, were determined in accordance with , (Equations 2–3) (Bračko, 2022) of paper samples after exposure w the ISO 11475 standard based on measurements with an Eye-One spectrophotometer (X-Rite, USA). to low temperatures for 6, 12, and 18 days, respectively, were determined in accordance with the ISO 11475 CIE whiteness, W, and tint of whiteness, T The results represent the average of five measurements and are shown in Tables 1–3. w , (Equations 2–3 ) (Bračko, 2022) of paper samples after standard based on measurements with an Eye-One spectrophotometer (X-Rite, USA). The results represent the exposure to low temperatures for 6, 12, and 18 days, respectively, were determined in accordance with average of five measurements and are shown in Tables 1–3. the ISO 11475 standard based on measurements with an Eye-One spectrophotometer (X-Rite, USA). 𝑊𝑊𝑊𝑊 = 𝑌𝑌𝑌𝑌 + 800( 𝑥𝑥𝑥𝑥 0 − 𝑥𝑥𝑥𝑥 ) + 1700( 𝑦𝑦𝑦𝑦 (2) 0 − 𝑦𝑦𝑦𝑦 ) The results represent the average of five measurements and are shown in Tables 1–3. 𝑊𝑊𝑊𝑊 𝑇𝑇𝑇𝑇 𝑊𝑊𝑊𝑊 = 1000(𝑥𝑥𝑥𝑥0 − 𝑥𝑥𝑥𝑥) − 650(𝑦𝑦𝑦𝑦0 − 𝑦𝑦𝑦𝑦) (3) = 𝑌𝑌𝑌𝑌 + 800( 𝑥𝑥𝑥𝑥 0 − 𝑥𝑥𝑥𝑥 ) + 1700( 𝑦𝑦𝑦𝑦 0 − 𝑦𝑦𝑦𝑦 ) (2) (2) 3. RESULTS AND DISCUSSION 𝑇𝑇𝑇𝑇 (3) 𝑊𝑊𝑊𝑊 = 1000( 𝑥𝑥𝑥𝑥 0 − 𝑥𝑥𝑥𝑥 ) − 650( 𝑦𝑦𝑦𝑦 0 − 𝑦𝑦𝑦𝑦 ) (3) constant temperature of 23 °C, 6 °C or –12 °C or at an alternating temperature of 6 and 23 °C, expressed 3. RESULTS AND DISCUSSION Figure 1 shows the mechanical durability of prints after exposure or storage for 6, 12 or 18 days at a as colour difference, ΔE*ab. Figure 1 shows the mechanical durability of prints after exposure or storage for 6, 12 or 18 days at a constant temperature of 23 °C, 6 °C or –12 °C or at an alternating temperature of 6 and 23 °C, expressed as colour difference, ΔE*ab. 2 2 476 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS AND DISCUSSION 29–30 May 2025, Ljubljana, Slovenia Figure 1 shows the mechanical durability of prints after exposure or storage for 6, 12 or 18 days at a constant temperature of 23 °C, 6 °C or –12 °C or at an alternating temperature of 6 and 23 °C, expressed as colour differ- ence, ΔE* . ab Figure 1: Figure 1: Durability of prints to rubbing after exposure to low temperature for 6, 12 and 18 days, Durability of prints to rubbing after exposure to low temperature for 6, 12 and 18 days, respectively, expressed as respectively, expressed as colour difference, Δ E *ab . colour difference, ΔE * . ab The results show that for a given combination of selected paper and ink (C, M, Y, K), low temperature The results show that for a given combination of selected paper and ink (C, M, Y, K), low temperature and the and the process of cooling or even freezing and heating and subsequent thawing does not significantly of the print to rubbing, as the colour differences are small or moderate and do not exceed 3.25 ΔE exceed 3.25 ΔE*ab units. The resulting changes are comparable to the results obtained at room * units. The ab temperature. Nevertheless, certain changes and trends can be observed. process of cooling or even freezing and heating and subsequent thawing does not significantly affect the durability affect the durability of the print to rubbing, as the colour differences are small or moderate and do not resulting changes are comparable to the results obtained at room temperature. Nevertheless, certain changes and trends can be observed. Colour prints (C, M, Y) with a higher ink application (100%) are generally slightly less durable than prints Colour prints (C, M, Y) with a higher ink application (100%) are generally slightly less durable than prints with a with a lower ink application (50%). After rubbing, slightly more significant colour differences appear on M100 and Y100, regardless of the temperature and duration of exposure (for C prints up to 0.77 ΔE up to 0.77 Δ E *ab units (T = alternating, t = 18 days), for M prints up to 1.38 Δ E *ab units (T = 23 °C, t = 6 * units (T = ab * alternating, t = 18 days), for M prints up to 1.38 ΔE lower ink application (50%). After rubbing, slightly more significant colour differences appear on samples C100, samples C100, M100 and Y100, regardless of the temperature and duration of exposure (for C prints (T = –12 °C, 18 days)). The exception is the yellow print after 18 hours of exposure to alternating temperature, days), for Y prints up to 2.51 ΔE*ab units (T = –12 °C, 18 days)). The exception is the yellow print after units (T = 23 °C, t = 6 days), for Y prints up to 2.51 ΔE * units ab ab 18 hours of exposure to alternating temperature, where the change of Y50 is practically the same as that of Y100. where the change of Y50 is practically the same as that of Y100. On the other hand, black prints with 50% coating (K50) are less durable than K100 as after rubbing larger colour On the other hand, black prints with 50% coating (K50) are less durable than K100 as after rubbing differences can be observed, regardless of the temperature and duration of exposure. The largest changes of the larger colour differences can be observed, regardless of the temperature and duration of exposure. The K50 sample occur at T = –12 °C, where the colour differences reach ΔE largest changes of the K50 sample occur at T = –12 °C, where the colour differences reach * = 1.78 after 18 days. ΔE*ab = 1.78 ab after 18 days. Longer exposure time (12 or 18 days compared to 6 days) to low temperature, even for prints with 50% applica- tion, does not significantly worsen resistance to rubbing; colour differences increase slightly after 18 days in the Longer exposure time (12 or 18 days compared to 6 days) to low temperature, even for prints with 50% * case of Y100, T = –12 °C (ΔE application, does not significantly worsen resistance to rubbing; colour differences increase slightly after increases by 1.53 units), M100, T = alternating (ΔE * increases by 0.85 units) and ab ab K50, T = 23 °C (ΔE * 18 days in the case of Y100, T = –12 °C ( increases by 0.46 units). ab Δ E *ab increases by 1.53 units), M100, T = alternating ( Δ E *ab increases by 0.85 units) and K50, T = 23 °C ( Δ E *ab increases by 0.46 units). There are minor differences in durability between prints of different colours with 100% application: the most resis- tant print is C100 (ΔE* = 0.79 – 1.15), and the least resistant is Y100 (ΔE* = 1.36 – 3.25). In the case of 50% There are minor differences in durability between prints of different colours with 100% application: the ab ab application, the permanence of colour prints (C, M, Y) is very similar. Colour differences resulting from rubbing most resistant print is C100 ( Δ E *ab = 0.79 – 1.15), and the least resistant is Y100 ( Δ E *ab = 1.36 – 3.25). In the case of 50% application, the permanence of colour prints (C, M, Y) is very similar. Colour differences resulting from rubbing range from ΔE*ab = 0.40 (Y50, T = 23 °C) to ΔE*ab = 1.12 (M50, T = – 12 °C) after 6 days of exposure. The resistance of colour prints is slightly better than black (K50), where colour differences after 6 days of exposure range from ΔE*ab = 1.21 to 1.65 units. 477 3 29–30 May 2025, Ljubljana, Slovenia range from ΔE* = 0.40 (Y50, T = 23 °C) to ΔE* = 1.12 (M50, T = –12 °C) after 6 days of exposure. The resistance ab ab of colour prints is slightly better than black (K50), where colour differences after 6 days of exposure range from ΔE* = 1.21 to 1.65 units. ab On average, the changes in the prints are minor to moderate and do not exceed 3.25 ΔE* units, and the results ab at lower temperatures are comparable to the results at room temperature (Table 1). Table 1: Average colour differences, ΔE* , after exposure of CMYK samples to low temperatures ab (T = 23, 6, –12 °C or alternating) and rubbing. Exposure ΔE*ab 6 days 12 days 18 days T/t 100% 50% 100% 50% 100% 50% 23 °C 1.67 0.86 1.62 1.08 1.48 1.12 6 °C 1.63 1.11 1.54 0.99 1.29 1.06 –12 °C 1.24 0.97 1.35 0.87 1.69 0.94 6/23 °C 1.46 0.95 1.35 0.86 1.05 0.75 We also checked how the optical properties of the printing material i.e. paper change during storage (Tables 2 and 3). The effect of low temperatures is small and practically identical at all temperatures: the whiteness of the paper slightly decreased during the storage both at room and at lower temperature (from 0.6 to 1.2 units after 6 days and 1.2 to 1.6 units after 18 days). The paper has a minimal reddish tint (T = –0.6), which deepens only slightly (T = w w –0.9) after 6, 12 or 18 days of exposure to low temperature, but the changes are so small that they would hardly be noticeable to the naked eye. Table 2: CIE whiteness, W, after exposing paper samples to low temperature. Exposure W T/t 0 6 days 12 days 18 days 23 °C 121.2 120.0 120.2 120.0 6 °C 121.2 120.4 119.4 120.6 –12 °C 121.2 120.6 119.9 119.6 6/23 °C 121.2 120.6 119.6 119.8 Table 3: Tint of whiteness, T , after exposing paper samples to low temperature. w Exposure T w T/t 0 6 days 12 days 18 days 23 °C –0.63 –0.89 –0.88 –0.83 6 °C –0.63 –0.81 –0.92 –0.90 –12 °C –0.63 –0.84 –0.88 –0.87 6/23 °C –0.63 –0.83 –0.89 –0.88 478 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS The present research analysed the influence of low temperatures on the mechanical durability of inkjet prints. The resistance to rubbing was tested for prints previously exposed to constant low temperature for a certain period, or alternately to room temperature and low temperature. The results were compared with the values for samples stored at room temperature before rubbing. According to the results, exposure to low temperatures did not cause serious destructive effects on the durability of the prints. Colour differences due to mechanical stress were small or moderate and did not exceed 3.25 ΔE* units on average, and results at lower temperatures were comparable ab to those at room temperature. Colour prints (CMY) with a higher ink application (100%) were generally slightly less durable than those with lower ink application (50%). On the other hand, black prints with 50% coating were less durable than those with 100 % coverage regardless of the temperature and duration of exposure. A very important factor in the degradation process is the printing material, which, in our case, showed excellent durability. In the future, expanding the research and systematically analysing its impact would be reasonable. 5. REFERENCES Bamfield, P. 2001. Chromic phenomena: technological applications of colour chemistry. Cambridge: The royal society of chemistry. Bevk, E., Blaznik, B. and Bračko, S. 2023. “Impact of protective glass on photodegradation of ink-jet printed documents.” Journal of cultural heritage. 62 (7/8): 356–362. Blaznik, B., Možina, K. and Bračko, S. 2013. “Stability of ink-jet prints under influence of light.” Nordic Pulp and Paper Research Journal 28: 111–118. Blaznik, B., Gregor-Svetec, D. and Bračko, S. 2017. “Influence of light and temperature on optical properties of papers.” Cellulose chemistry and technology 51 (7/8): 755–764. Blaznik, B., Kovač, F., Bizjak, G. and Bračko, S. 2022. “Fastness of dye-based ink-jet printing inks in aqueous solution in the presence and absence of oxygen.” Color research and application 47 (5): 1193–1199. Bračko, S. and Blaznik, B. 2022. Osnove merjenja barv. Ljubljana: Univerza v Ljubljani, Naravoslovnotehniška fakulteta. Feller, R. L. 1994. Accelerated aging: photochemical and thermal aspects. Los Angeles: Getty Conservation Institute. Hoath, S. D. 2016. Fundamentals of Inkjet Printing. Weinheim: Wiley-VCH. Izdebska, J. 2016. Aging and degradation of polymers. Printing on polymers. Editors Izdebska, J. and Thomas, S. Oxford: William Andrew Publishing. Magdassi, S. 2010. The Chemistry of Inkjet Inks. Singapore: World Scientific Publishing. Pastorelli, G., Cucci, C., Garcia, O., Piantanida, G, Elnaggar, A., Cassar, M. and Strlič, M. 2014. “Environmentally induced colour change during natural degradation of selected polymers.” Polymer Degradation and Stability 56:198–209. Venosa, A., Burge, D. and Nishimura, D. 2011. “Effect of light on modern digital prints: photographs and documents.” Studies in Conservation 56: 267–280. Wypych, G. 2008. Handbook of material weathering. 4th ed. Toronto: ChemTec Publishing. Zollinger, H. 2003. Color Chemistry: Syntheses, properties and applications of organic dyes and pigments. 3rd ed. Weinheim: Verlag Helvetica Chimica Acta. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-authors: Sabina Bračko Barbara Blaznik Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering University of Ljubljana University of Ljubljana Snežniška 5 Snežniška 5 1000 Ljubljana, Slovenia +386 1 200 32 22 1000 Ljubljana, Slovenia barbara.blaznik@ntf.uni-lj.si +386 1 200 32 38 sabina.bracko@ntf.uni-lj.si Maša Šraj University of Ljubljana Faculty of Natural Sciences and Engineering Snežniška 5 1000 Ljubljana, Slovenia 479 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION SCREEN PRINTING WITH DYES FROM INVASIVE ALIEN PLANTS Maja Klančnik1 and Katarina Lampič1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The research presents a comparative study on the applicability of natural dyes from three different inva-sive alien plants, namely goldenrod, Himalayan balsam and Japanese knotweed, for screen printing on different papers and shows the possible influence of printing pastes with different pH values in the formulation of printing inks on the final colour and durability of prints. Commercially available cellulose papers made from primary and secondary cellulose fibres as well as innovative papers made from the stems of Japanese knotweed were used for printing. The printed substrates were evaluated on the basis of colour measurements and fastness properties. The results confirmed that the inks made from natural dyes produced with both printing pastes can be successfully used for screen printing on all papers and exhibit very good rub resistance. However, the lower light fastness of the prints made with the dyes from the petals of Himalayan balsam and the leaves of Japanese knotweed limits their use for outdoor paper products. The different pH of the printing paste also had a great influence on the colour of the prints of all dye extracts and on the fastness of the prints made with the Japanese knotweed leaves. The prints made with the yellow dye extract from goldenrod flowers showed the best fastness properties on all the papers tested. Keywords: natural dye, invasive alien plant, printing, paper. 1. INTRODUCTION Invasive alien plants pose an ecological problem as they grow on a large scale and displace native plants. The possibility of using them as a source of natural dyes for dyeing textiles, printing on textiles and paper, and coating wood has therefore been the subject of several studies (Gorjanc, 2016; Gorjanc, 2019; Topič, 2017; Klančnik, 2021; Klančnik, 2021; Klančnik, 2024; Horvat, 2020). In our study, the dye extracts from the yellow petals of goldenrod, the green leaves of Japanese knotweed and the pink petals of Himalayan balsam were used to produce screen printing inks. The research work represents a comparative study of the possible influence of printing pastes with slightly different pH values in the formulation of printing inks on the final colour and durability of the prints. For this purpose, the pigment printing paste with a pH value of 7.4, which was produced by mixing individual components such as acrylic thickener and acrylic binder in distilled water, and the commercially produced printing paste with a pH value of 8.1 were used for comparison. The inks produced from three dye extracts using two different printing pastes were printed by flat screen printing on two papers made from Japanese knotweed stems of different grammages and on two commercially available papers, one made from primary cellulose fibres and one from recycled cellulose fibres. The colour of the prints was evaluated spectrophotometrically, and the abrasion and light resistance of the prints was tested. The printing of papers with dyes from Himalayan balsam (Klančnik, 2021) and Japanese knotweed leaves (Klančnik, 2024) has already been demonstrated, but not in comparison to printing with the dye from goldenrod and the printing pastes with different pH values. 2. EKSPERIMENTAL 2.1 Dye extracts The dye extracts from the leaves of Japanese knotweed, form the petals of goldenrod and Himalayan Balsam were obtained from National Institute of Chemistry (Ljubljana, Slovenia). 480 29–30 May 2025, Ljubljana, Slovenia 2.2 Printing Ink Preparation For the screen printing inks, the already commercially prepared pigment printing paste Transparent Elastil FGI (AchitexMinerva Ltd., Vaiano Cremasco, Italy) with a pH value of 8.1 was used and the printing paste, which we prepared by mixing the individual ingredients according to the following recipe: 150 g Binder SE conc. (Achitex-Minerva Ltd., Vaiano Cremasco, Italy), 18 g thickener Clear MCS (AchitexMinerva Ltd., Vaiano Cremasco, Italy) and up to 1000 g demineralized water to form a homogeneous paste with a pH value of 7.4. The dye extract from goldenrod petals was added in the following concentrations: 1 and 3 g per 100 g of the printing paste we produced with pH 7.4 and per 100 g of the commercially available Transparent Elastil printing paste with pH 8.1. The dye extracts from the Japanese knotweed leaves and Himalayan balsam petals were added in concentrations of 1 and 3 g per 100 g of Transparent Elastil printing paste with pH 8.1 and in a concentration of 3 g per 100 g of the printing paste with pH 7.4. The formulated inks are shown in Figure 1. Figure 1: The printing inks produced with dye extracts from goldenrod (in the first row), with dye extracts from Japanese knotweed leaves (in the second row) and with dye extracts from Himalayan balsam (in the third row). 2.3 Printing Materials The following papers were used for printing: Japanese knotweed papers in two grammages, 200 and 240 g/m², produced by the Pulp and Paper Institute (Ljubljana, Slovenia), hereafter referred to as J.k. 200 and J.k. 240, where J.k. 200 contains approx. 30 % Japanese knotweed fibres and J.k. 240 approx. 40 % fibres from Japanese knotweed, the remainder being commercially available cellulose fibres, and paper made from primary cellulose fibres with the trade name IQ premium (manufactured by Mondi Group Ltd, Vienna, Austria), grammage 200 g/ m², referred to as Paper 1, and recycled paper from an unknown manufacturer, grammage 200 g/m², referred to as Paper 2. 2.4 Printing The printing inks were applied by the semi-automatic screen-printing machine SD 05 (RokuPrint Ltd., Darmstadt, Germany) with the flat printing screen made of polyester fabric with 77 threads/cm and a thread diameter of 55 µm with three strokes of squeegee. The prints were dried at room temperature overnight and then cured at 150 °C for 5 minutes. 2.5 Spectrophotometric Measurements Colour measurements of the prints were made using the Eye-One i1 Pro spectrophotometer (X-Rite, Grand Rap-ids, MI, USA) with 45/0 plane geometry, illuminant D65, 10° standard observer and a 4.5 mm diameter aperture. The CIELAB colour coordinates: L* (lightness), a* (red-green value), b* (yellow-blue value) in the range of 380 to 730 nm were measured, the average of three measurements for each print was taken, and h (hue) and C* abab (chroma) were calculated. 481 29–30 May 2025, Ljubljana, Slovenia 2.6 Colour Fastness Tests The abrasion resistance of the ink layer on papers was tested according to ASTM D 5264 using the digital ink rub tester RT-01 (Labthink Ltd., Neu-Isenburg, Germany) at an abrasion pressure of 1.81 kg and at an abrasion frequency of 1.8 s-1 with 500 strokes. The transfer of ink from the prints to the white paper (Paper 1) used as a re-ceptor, and the damage of printed surface after rubbing were visually assessed. The colour fastness of the prints to artificial light (xenon arc fading lamp) was tested according to ISO 105-B02: 2014 using the Xenotest Alpha tester (Atlas, Rancho Cucamonga, CA, ZDA) under the following conditions: 35 °C, 35% relative humidity and 72 h, together with the standard blue reference scale. The colour change of the exposed prints was visually assessed using the blue wool references with ratings from 1 to 8, with 8 being the best value. 3. RESULTS WITH DISCUSSION The prints produced with inks made from the dye extract of goldenrod flowers were light yellow, there were no ma-jor differences in colour and fastness properties when different printing pastes were used, except on white paper made from primary cellulose fibres, where the printing paste with a pH of 7.4 gave more yellowish and saturated prints than the commercially produced printing paste with a pH of 8.1 (Table 1). Table 1: Colour values of prints produced with goldenrod dye extract Colour values 1 g/100 g paste of 3 g/100 g paste of 1 g/100 g paste of 3 g/100 g paste of pH 7.4 pH 7.4 pH 8.1 pH 8.1 On J.k. 200 L* 82.81 82.98 83.07 83.40 a* 0.89 0.50 1.22 0.82 b* 16.52 18.80 15.76 17.67 C* 16.54 18.81 15.81 17.69 ab h (°) 86.92 88.48 85.57 87.34 ab On J.k. 240 L* 74.26 74.62 73.67 74.36 a* 4.08 4.23 4.32 3.80 b* 22.61 22.21 23.68 23.21 C* 22.97 22.61 24.07 23.52 ab h (°) 79.77 79.22 79.66 80.70 ab On Paper 1 L* 92.82 92.70 91.95 92.43 a* -0.30 -2.60 -0.07 -1.24 b* -3.27 4.79 -2.11 -0.19 C* 3.28 5.45 2.11 1.25 ab h (°) 264.76 118.49 268.10 188.71 ab 482 29–30 May 2025, Ljubljana, Slovenia On Paper 2 L* 92.07 90.97 90.73 90.38 a* -1.41 -3.19 -2.00 -2.96 b* 5.67 12.85 8.86 12.79 C* 5.84 13.24 9.08 13.13 ab h (°) 103.97 103.94 102.72 103.03 ab All prints made with the goldenrod extract inks showed excellent resistance to dry abrasion (Table 2). The best light fastness of the prints among all dye extracts was achieved with these inks, the light fastness of the prints according to the blue scale was on average grade 6, on white paper even grade 7 with both printing pastes. Only on recycled paper the prints of the goldenrod extracts became darker after exposure to light. Table 2: Fastness properties of prints made with goldenrod dye extract Fastness 1 g/100 g 3 g/100 g 1 g/100 g 3 g/100 g paste of pH paste of pH paste of pH paste of pH 7.4 7.4 8.1 8.1 On J.k. 200 Dry rubbing (assessment of printed No change No change No change No change surface) Dry rubbing (assessment of white No ink No ink No ink No ink paper) transfer transfer transfer transfer Light fastness (blue reference) 6-7 6 6 6 On J.k. 240 Dry rubbing (assessment of printed No change No change No change No change surface) Dry rubbing (assessment of white No ink No ink No ink No ink paper) transfer transfer transfer transfer Light fastness (blue reference) 5-6 5 5 5 On Paper 1 Dry rubbing (assessment of printed No change No change No change Slightly surface) rubbed Dry rubbing (assessment of white No ink No ink No ink No ink paper) transfer transfer transfer transfer Light fastness (blue reference) 8 7 7 7 On Paper 2 Dry rubbing (assessment of printed No change No change No change No change surface) Dry rubbing (assessment of white No ink No ink No ink No ink paper) transfer transfer transfer transfer Light fastness (blue reference) 5 darker 6 darker 5 darker 5 darker The prints made with the dye extract from the leaves of Japanese knotweed were yellowish-green, lighter when the printing paste with a pH of 7.4 was used and more intense when the commercial printing paste with a pH of 8.1 was used (Table 3). 483 29–30 May 2025, Ljubljana, Slovenia Table 3: Colour values of prints produced with Japanese knotweed Colour values 1 g/100 g paste of 3 g/100 g paste of 1 g/100 g paste of 3 g/100 g paste of pH 7.4 pH 7.4 pH 8.1 pH 8.1 On J.k. 200 L* / 79.56 80.97 75.30 a* / 0.03 0.90 0.68 b* / 26.26 21.32 29.91 C* / 26.26 21.34 29.92 ab h (°) / 89.93 87.58 88.70 ab On J.k. 240 L* / 70.39 75.99 69.14 a* / 3.65 2.93 3.91 b* / 30.22 25.06 30.84 C* / 30.44 25.23 31.00 ab h (°) / 83.11 83.33 84.09 ab On Paper 1 L* / 87.48 90.29 83.58 a* / -2.54 -1.03 -2.89 b* / 16.93 3.60 22.36 C* / 17.15 3.74 22.55 ab h (°) / 98.53 105.97 97.37 ab On Paper 2 L* / 88.48 89.21 84.64 a* / -2.42 -2.21 -3.78 b* / 17.96 13.19 24.92 C* / 18.12 13.37 25.20 ab h (°) / 97.68 99.51 98.63 ab The prints made from Japanese knotweed extract using the printing paste with a pH value of 7.4 were more resis-tant to dry rubbing and light (fastness grade 4) than the prints made using the commercial printing paste with a pH value of 8.1, while the prints on the Japanese knotweed papers were rubbed off after the rub resistance test and the light fastness of the prints of a higher concentration on all papers deteriorated sharply (grade 2). 484 29–30 May 2025, Ljubljana, Slovenia Table 4: Fastness properties of prints made with Japanese knotweed Fastness 1 g/100 g 3 g/100 g 1 g/100 g 3 g/100 g paste of pH paste of pH paste of pH paste of pH 7.4 7.4 8.1 8.1 On J.k. 200 Dry rubbing (assessment of printed / No change No change Slightly surface) rubbed Dry rubbing (assessment of white / No ink No ink No ink paper) transfer transfer transfer Light fastness (blue reference) / 4 4-5 2 On J.k. 240 Dry rubbing (assessment of printed / No change No change Slightly surface) rubbed Dry rubbing (assessment of white / No ink No ink No ink paper) transfer transfer transfer Light fastness (blue reference) / 3 4-5 2 On Paper 1 Dry rubbing (assessment of printed / Slight shine No change No change surface) Dry rubbing (assessment of white / Slight ink No ink No ink paper) transfer transfer transfer Light fastness (blue reference) / 4 2 2 On Paper 2 Dry rubbing (assessment of printed / No change No change No change surface) Dry rubbing (assessment of white / Slight ink No ink No ink paper) transfer transfer transfer Light fastness (blue reference) / 4-5 5-6 3 The colour of the prints made from the petals of the Himalayan balsam was strongly influenced by the printing pastes with different pH values. The prints made with the printing paste with a pH of 7.4 were more intense purplish brown, while the prints made with the commercially prepared printing paste with a pH of 8.1 were more brown (Table 5). 485 29–30 May 2025, Ljubljana, Slovenia Table 5: Colour values of prints produced with Himalayan balsam Colour values 1 g/100 g paste of 3 g/100 g paste of 1 g/100 g paste of 3 g/100 g paste of pH 7.4 pH 7.4 pH 8.1 pH 8.1 On J.k. 200 L* / 77.56 80.71 76.36 a* / 4.17 2.30 3.69 b* / 14.26 15.46 17.67 C* / 14.86 15.63 18.05 ab h (°) / 73.70 81.54 78.20 ab On J.k. 240 L* / 69.46 71.31 68.15 a* / 6.65 4.90 5.95 b* / 21.52 22.69 23.18 C* / 22.52 23.21 23.93 ab h (°) / 72.83 77.81 75.60 ab On Paper 1 L* / 81.27 89.79 83.31 a* / 4.03 1.66 2.22 b* / 3.69 -3.81 5.81 C* / 5.46 4.16 6.22 ab h (°) / 42.48 293.54 69.09 ab On Paper 2 L* / 85.73 89.45 84.05 a* / 1.04 -0.39 0.44 b* / 5.74 5.78 10.51 C* / 5.83 5.79 10.52 ab h (°) / 79.73 93.86 87.61 ab The rub resistance test showed that the prints on papers with the Himalayan balsam dye extract rubbed off a little, except on white paper made from primary cellulose fibres, where the resistance with both printing pastes was excellent (Table 6). The light fastness of the prints made with the Himalayan balsam dye extract was only 3 on average with both printing pastes, except on the recycled paper where the light fastness of the prints was better with a grade of 4-5. 486 29–30 May 2025, Ljubljana, Slovenia Table 6: Fastness properties of prints made with Himalayan balsam Fastness 1 g/100 g 3 g/100 g 1 g/100 g 3 g/100 g paste of pH paste of pH paste of pH paste of pH 7.4 7.4 8.1 8.1 On J.k. 200 Dry rubbing (assessment of printed / Slightly No change Slightly surface) rubbed rubbed Dry rubbing (assessment of white / No ink No ink No ink paper) transfer transfer transfer Light fastness (blue reference) / 3-4 5-6 3-4 On J.k. 240 Dry rubbing (assessment of printed / Slightly No change Slightly surface) rubbed rubbed Dry rubbing (assessment of white / No ink No ink No ink paper) transfer transfer transfer Light fastness (blue reference) / 3 5 3 On Paper 1 Dry rubbing (assessment of printed / No change No change No change surface) Dry rubbing (assessment of white / No ink No ink No ink paper) transfer transfer transfer Light fastness (blue reference) / 2 5 2 On Paper 2 Dry rubbing (assessment of printed / Slightly No change Slightly surface) rubbed rubbed Dry rubbing (assessment of white / No ink No ink No ink paper) transfer transfer transfer Light fastness (blue reference) / 4-5 4-5 4-5 4. CONCLUSIONS The research results confirmed that the printing inks made from natural dyes using pigment printing pastes can be successfully used for screen printing on various papers and have very good rub resistance. However, the lower light fastness of the prints made with the dyes from Himalayan balsam petals and Japanese knotweed leaves limits their use for outdoor paper products. The different pH value of the printing paste also had a great influence on the colour of the prints of all dye extracts and on the fastness of the prints made with the leaves of Japanese knotweed. The prints made with the yellow dye extract from goldenrod flowers showed the best fastness proper-ties on all the papers tested. 487 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Gorjanc, M., Savić, A., Topalić-Trivunović, L., Mozetič, M., Zaplotnik, R., Vesel, A. and Grujić, D. 2016. “Dyeing of plasma treated cotton and bamboo rayon with Fallopia Japonica extract.” Cellulose 23: 2221–2228. Gorjanc, M., Kert, M., Mujadžić, A., Simončič, B., Forte-Tavčer, P., Tomšič, B. and Kostanjšek, K. 2019. “Cationic pretreatment of cotton and dyeing with Fallopia Japonica leaves.” Tekstilec 62:181–186. Horvat, M., Iskra, J., Pavlič, M., Žigon, J. and Merela, M. 2020. “Wood dyes from invasive alien plants.” Les Wood 69: 37–48. Klančnik, M. 2021. “Screen Printing with Natural Dye Extract from Japanese Knotweed Rhizome.” Fiber Polym. 22: 2498–2506. Klančnik, M. 2021. “Printing with Natural Dye Extracted from Impatiens glandulifera Royle.” Coatings 11: 445–457. Klančnik, M. 2024. “Printing with Natural Dye Extract from Japanese Knotweed Leaves.” Fibers Polym. 25: 4771–4785. Topič, T., Gorjanc, M. and Kert, M. 2018. “The influence of the treatment process on the dyeability of cotton fabric using goldenrod dye.” Tekstilec 61: 192–200. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author: Maja Klančnik Katarina Lampič Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška 5 Snežniška 5 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia maja.klancnik@ntf.uni-lj.si 488 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION REPRODUCTION OF COLOUR PATCHES ON TEXTILE AND PAPER MATERIALS Ana Mendizza1 and Raša Urbas1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: This study compares the colour reproduction capabilities of two Canon inkjet printers: the older ima-gePROGRAF W8400 and the newer imagePROGRAF PRO-4000S. Using the same paper (EMBLEM Water Coated Paper 180) and a textile substrate (Blackout VI DirectTex), we evaluated colour accuracy, colour gamut size and overall print quality. The results showed that the PRO-4000S with its extended eight-ink system produced a significantly larger colour gamut and more accurate colours compared to the older six-ink W8400. On paper, colour differences were minimal, but on textile material, colour accuracy decreased due to the limitations of the substrate. This underlines the importance of substrate-specific colour management strategies and adapted ICC profiles to optimise colour consistency when printing on different materials. Keywords: ICC profiles, colour accuracy, colour differences, inkjet printing, Canon imagePROGRAF. 1. INTRODUCTION Today’s rapid technological advances are changing the industry, and the printing industry is no exception. Inno-vations in digital printing, ink formulations and materials science are revolutionising the way we reproduce colour, enabling greater accuracy, efficiency and adaptability across a wide range of applications and materials. Technological advances such as faster presses, improved ink technology and hybrid printing solutions are en-hancing production efficiency and quality. The global market for commercial printing is driven by the increasing demand for printed marketing materials such as brochures, leaflets and packaging. Digital printing is the fastest growing segment, driven by innovations in inkjet, laser printing and AI integration. Despite challenges such as rising raw material costs and the switch to digital media, the market is finding opportunities in environmentally friendly processes such as soya-based inks and recycled paper. (Grand View Research, 2024) Like many industry leaders, Canon utilises its research and development departments to continuously develop printing technologies. Through continuous investment in research and development (R&D), Canon develops new ink formulations, improves printhead precision and expands media compatibility. The result of these efforts are innovations such as a wider colour gamut, better colour consistency and faster print production. The LUCIA PRO ink system, for example, has significantly improved colour fidelity and durability and meets the high demands of professional photographers, artists and print service providers. With faster print speeds and improved media handling, including the ability to print on various materials such as textiles, canvas and technical papers, Can-on’s imagePROGRAF line continues to push the boundaries of modern printing. These technological advances fulfil the market’s growing demand for high-quality, reliable and efficient printing solutions and demonstrate how strategic R&D investment can drive innovation in the industry and meet evolving customer needs. (Canon, 2025) Accurate colour reproduction has become a critical requirement in industries ranging from commercial printing and packaging to textiles and industrial applications. Customers and brands expect visually consistent prints that perfectly match digital designs, which requires colour management and precise printer calibration. The need for colour accuracy extends beyond traditional media as new substrates–such as synthetic papers, synthetic, spe-ciality and technical textiles, flexible films, and textured surfaces–are being introduced to expand the possibilities 489 29–30 May 2025, Ljubljana, Slovenia of print applications. Each of these materials has specific requirements for ink absorption, reflectivity and colour gamut compatibility, requiring bespoke colour profiling and workflow optimisation. When printing, it is crucial to know the properties of the substrate, as they significantly influence the quality and durability of the final print. Unlike paper, textile materials have a wider range of variables, including fabric stru-cture, raw material composition, thread density and physical properties such as yarn diameter, fabric thickness and whiteness. In contrast, paper substrates have precisely defined properties such as grammage, thickness, brightness, smoothness and absorbency. These properties all influence the final print quality, so it is important to take them into account when making accurate comparisons and evaluations. A thorough understanding of these properties is essential for industries seeking high-quality, reproducible prints with accurate detail and colour re-production. (Mendizza, 2024) 2. EXPERIMENTAL 2.1 Printers and printing substrates To asses the advances in printing technology, we first carried out a comparative analysis of prints made with an older Canon imagePROGRAF W8400 printer and a newer Canon imagePROGRAF PRO-4000S (Figure 1). Both printers are inkjet printers and use water-based inks. The W8400 uses a six-colour ink system with cyan, magenta, yellow, black, light cyan and light magenta, while the PRO-4000S uses an advanced eight-ink configu-ration that includes photo black, matte black, cyan, magenta, yellow, photo cyan, photo magenta and grey. This comparison allowed us to assess the improvements in colour accuracy, colour gamut size and overall print quality resulting from advances in printing technology. Figure 1: Canon imagePROGRAF W8400(left), Canon imagePROGRAF PRO-4000S (right) (Canon, 2025) In the first part of our study, both printers used the same paper substrate to ensure consistency in the evaluation process. The chosen substrate was EMBLEM Water Coated Paper 180 (manufactured by Dataplot, Germany), a high-quality printing paper with a grammage of 180 g/m². This paper is ultra-white, has a heavy matt coating and is specifically designed to improve colour reproduction and ink adhesion, making it an ideal choice for accurate colour evaluation (Dataplot, 2021). By maintaining identical printing conditions, we wanted to isolate and empha-sise the differences in performance due to the printers themselves. In the second part of our study, we wanted to evaluate the print quality of the newer printer, Canon image-PROGRAF PRO-4000S, on different substrates to assess its adaptability and performance. In particular, we com-pared prints on a paper substrate with those on a textile substrate to determine how the material properties affect colour reproduction, colour fidelity and consistency. The textile substrate we chose was Blackout VI DirectTex (manufactured by Pongs, Germany), a high-quality fabric designed for direct printing applications. This material is 490 29–30 May 2025, Ljubljana, Slovenia characterised by a dense, opaque structure that minimises light transmission. This makes it suitable for applica-tions that require vibrant colours and high contrast. (Pongs, 2024) By analysing prints on EMBLEM Water Coated Paper 180 and Blackout VI DirectTex, we wanted to determine the printer‘s strengths and limitations when working with different substrates and which materials deliver the most accurate and consistent colour results. 2.2 Colour management and the printing process To ensure repeatability, we created ICC profiles for both printers and the substrates tested. We used a spectro-photometer (i1Pro 2) and i1Profiler software to create custom ICC profiles that allowed us to accurately calibrate and characterise each printer-substrate combination. We created profiles for both the Canon imagePROGRAF W8400 and Canon imagePROGRAF PRO-4000S on EMBLEM Water Coated Paper 180 and for the Canon imagePROGRAF PRO-4000S on Blackout VI DirectTex. This ensures consistent and reproducible colour repro-duction across different print runs. By minimising variations due to device-specific characteristics, ink interactions and substrate properties, we have created a reliable basis for comparing colour accuracy, gamut size and overall print quality. The i1Pro 2 spectrophotometer (manufactured by X-Rite) is standardised according to ISO 13655:2017, an inter-national standard that defines the spectral measurement conditions for graphic arts applications. This standard specifies the use of the CIE 1931 standard colorimetric observer, which is based on a 2° field of view and simu-lates human colour perception under controlled conditions. In addition, the measurements were performed under a D50 illumination source, which corresponds to a standardised daylight condition with a correlated colour tem-perature of approximately 5000 K (ISO, 2017). This ensures consistency and comparability of colour data across different devices and printing environments. By adhering to these standardised methods, we have ensured the reliability of our colour profiling process and enabled an objective assessment of each printer’s performance in terms of colour accuracy and gamut size. 2.3 Colour chart To measure colour consistency, we selected the patches from the ColorChecker Classic test chart. The Color-Checker Classic is a widely recognised and standardised colour reference chart used in colour calibration and profiling. It consists of 24 colour patches, each representing a specific, carefully selected colour covering a range of hues, tones, and saturations commonly used in imaging and printing processes. These colour patches include a variety of primary and secondary colours, grayscale, and skin tones, making them a comprehensive tool for evaluating a printer‘s ability to accurately reproduce colours. (calibrate, 2025; Lindbloom, 2025) Using Adobe Illustrator, we designed the patches based on the ColorChecker Classic test chart and ensured that each patch exactly matched the intended colour values to enable accurate colour evaluation (Figure 2). 491 29–30 May 2025, Ljubljana, Slovenia Figure 2: ColorChecker Classic test chart, patches created in Adobe Illustrator 3. RESULTS WITH DISCUSSION 3.1 Visual comparison of the colour profiles To visually compare the colour gamuts of the ICC profiles, we used the macOS-based application ColorSync Utility. This tool enables the visualisation and comparison of ICC profiles and provides a detailed representation of the colour gamut of the individual printers (Apple, 2025). First, we compared the colour gamuts of the Canon imagePROGRAF W8400 and the Canon imagePROGRAF PRO-4000S using EMBLEM Water Coated Paper 180 as substrate. The colour gamut of the profile created with the older W8400 is visibly smaller (Figure 3, left). As this printer uses fewer colours, the result is a smaller colour gamut that is reproduced. In contrast, the newer Canon imagePROGRAF PRO-4000S has a much wider colour gamut, thanks to its extended ink set (Figure 3, right). With this extended ink set, the PRO-4000S can reproduce a much wider range of colours. Figure 3: Colour gamut of an ICC profile made on Canon imagePROGRAF W8400 (left), Colour gamut of an ICC profile made on Canon imagePROGRAF PRO-4000S 492 29–30 May 2025, Ljubljana, Slovenia In the second part of the study, we compared the ICC profiles created for the newer Canon imagePROGRAF PRO-4000S with two different substrates: paper and textile. This comparison allowed us to assess how the characteristics of the substrate, e.g. texture, material composition and coatings, affect colour reproduction and colour fidelity. The results show that the paper substrate EMBLEM Water Coated Paper 180 has a wider colour gamut (Figure 4, left) compared to the textile substrate Blackout VI DirectTex (Figure 4, right). This suggests that the paper substrate allows for a wider colour gamut, probably due to its smoother surface and more uniform ink absorption, while the textile substrate has a more limited colour gamut due to its porous nature and texture. Figure 4: Colour gamut of an ICC profile made on the Canon imagePROGRAF PRO-4000S for paper substrate (left) and textile substrate (right) 3.2 Colour differences For all patches on the ColorChecker Classic test chart, we measured the L*a*b* values and calculated the ΔE co-00 lour differences (Luo, 2001). The values for the colour differences can be divided into four groups. The first group includes colour differences from 0 to 1, where the difference is not perceptible to the naked eye. The second group ranges from 1 to 3, which represents a small colour difference. The third group includes differences from 3 to 6, where the colour difference is visible to the naked eye, and the fourth group consists of differences of more than 6, which indicates a significant colour difference. For the prints made with the Canon imagePROGRAF W8400 on paper substrate the average colour difference for all 24 patches was 4.2, with the lowest value being 1 and the highest 9. Most of the colour differences fall into the third group, where the differences are visible to the naked eye, with some patches exceeding a value of 6 and thus falling into the fourth group, which indicates large colour deviations. Figure 5 shows the printed patches. 493 29–30 May 2025, Ljubljana, Slovenia Figure 5: Patches on the paper substrate made with Canon imagePROGRAF W8400 The average colour difference of the patches made with the Canon imagePROGRAF PRO-4000S was 2.3, with the lowest value being 0.4 and the highest 5.1. The majority of the patches fall into the second group, where the differences are small but perceptible on closer inspection. Only a few patches reach the third group, which shows a general improvement in colour accuracy compared to the older printer. Figure 6 shows the printed patches. Figure 6: Patches on paper substrate made with Canon imagePROGRAF PRO-4000S For the textile substrate printed with the Canon imagePROGRAF PRO-4000S the average colour difference was 7.8, with the highest value being 14 and the lowest 2.7. The highest colour differences can be observed here, with most patches in the third and fourth group, i.e. the deviations are easily visible. Several patches exceed the value of 6, indicating a significant loss of colour accuracy due to substrate limitations. Figure 7 shows the printed patches. 494 29–30 May 2025, Ljubljana, Slovenia Figure 7: Photo of the patches on paper substrate made with Canon imagePROGRAF PRO-4000S The analysis of the colour differences shows that the colour accuracy varies greatly depending on the printer and the substrate used, which is reflected in the classifications of the colour difference groups. The highest colour differences are found on the textile substrate. This is primarily due to the limitations of ink application and the physical properties of the textile substrate. Unlike paper, which allows for precise ink deposition and controlled absorption, textiles exhibit higher ink diffusion, uneven absorption and variations in surface texture, all of which contribute to greater deviations from the reference colours. In addition, the smaller colour gamut of the textile substrate limits the ability to reproduce highly saturated and accurate colours. These results underline the importance of substrate-specific colour management strategies. Optimising ink ap-plication techniques, using appropriate print profiles and adjusting colour compensation settings are crucial for minimising perceptible colour differences when printing on different substrates. 4. CONCLUSION The experimental analysis of colour differences in conjunction with visual comparisons of the colour gamuts, high-lights significant differences in colour reproduction accuracy between the older Canon imagePROGRAF W8400 and the newer Canon imagePROGRAF PRO-4000S, as well as with different substrates. The results show that the newer Canon imagePROGRAF PRO-4000S with its expanded eight-ink configuration offers a significantly larger colour gamut and improved colour accuracy compared to the older six-ink Canon ima-gePROGRAF W8400. The wider colour gamut enables more accurate colour reproduction, and the newer prin-ter‘s ability to reproduce a wider colour gamut contributes to more accurate prints. The paper substrate, EMBLEM Water Coated Paper 180, also contributes to better colour reproduction due to its smooth surface and even ink absorption. This substrate showed a wider colour gamut and smaller colour differences, especially on the PRO-4000S, where most colour differences were in the small or low range (between 1 and 3). In contrast, the study showed a remarkable decrease in colour accuracy when printing on the Blackout VI Direc-tTex textile substrate. The textile substrate showed a more limited colour gamut and larger colour differences (more than 6). The inherent irregularities in the diffusion and absorption of the ink in the textile material, combined with the limited colour gamut of the substrate, contributed to larger deviations from the reference colours. These results highlight the challenges of consistent and accurate colour reproduction on textiles. The results emphasize the importance of substrate-specific colour management strategies. Optimising ink appli-cation, using customised ICC profiles and carefully adjusting colour compensation settings are critical to mi-nimising colour differences when working with different substrates. This study highlights that achieving colour consistency is not only dependent on the printer itself, but is also significantly influenced by the properties of the substrate, underlining the need for tailored approaches to colour management in the printing process. 495 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Apple. Title: ColorSync Utility User Guide. URL: https://support.apple.com/en-gb/guide/colorsync-utility/welcome/mac (last accessed on 1. 2. 2025). Calibrate. Title: ColorChecker Classic Mini. URL: https://calibrite.com/product/colorchecker-classic-mini/ (last accessed on 1. 2. 2025). Canon. Title: Canon USA. URL: https://www.usa.canon.com (last accessed on 1. 2. 2025). Dataplot. 2021. Data sheet EMBLEM Water Coated Paper 180. Henstedt-Ulzburg: Dataplot. Grand View Research. 2024. Commercial Printing Market Size, Share & Trends Analysis Report By Printing Technology (Digital Printing, Lithography Printing), By Application (Packaging, Advertising), By Region, And Segment Forecasts, 2025 - 2030. San Francisco: Grand View Research. ISO. 2017. ISO 13655:2017 Graphic technology — Spectral measurement and colorimetric computation for graphic arts images. ISO. Lindbloom, B. Title: Bruce Lindbloom. URL: http://www.brucelindbloom.com (last accessed on 1. 2. 2025). Luo, M. R., Cui, G. and Rigg, B. 2001. “The Development of the CIE 2000 Colour Difference Formula: CIEDE2000. ” Color Research and Application, vol. 26, no. 5, pp. 340–350, 2001. Mendizza, A. 2024. “Characterisation of prints made with inkjet printer Canon imagePROGRAF PRO- 4000s.” master’s thesis, University of Ljubljana. Pongs Technical Textiles GmbH. 2021. DirectTex® Blackout VI. URL: https://atech.co.uk/consumables-printable-fabrics/pongs-directtex-blackout-vi-pd-801.html (Retrieved 27. 1. 2024). ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author: Raša Urbas Ana Mendizza and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design, Chair of Information Chair of Information and Graphic Arts technology and Graphic Arts technology Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana Aškerčeva 12 Aškerčeva 12 1000 Ljubljana, Slovenia 1000 Ljubljana, Slovenia +386 1 200 3235 ana.mendizza@ntf.uni-lj.si +386 1 200 3283 rasa.urbas@ntf.uni-lj.si 496 PHOTOGRAPHY AND COLORIMETRY 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION COMPARATIVE STUDY OF NOISE REDUCTION TECHNIQUES FOR PHOTOGRAPHIC IMAGE ENHANCEMENT Ivana Jurič1, Ivana Tomić1, Sandra Dedijer1, Magdolna Pal1, Nemanja Kašiković1 1 and Katarina Maričić 1 University of Novi Sad, Faculty of Technical Sciences, Serbia Abstract: The quality of digital photographs is influenced by various factors, including noise, which can reduce image quality. Noise refers to unwanted artifacts that do not originate from the scene itself, distracting the viewer from important details. While noise is always present in digital photography, it can be minimized in cameras with larger pixels. Noise arises from physical effects like the photonic nature of light and thermal energy in the camera sensor. Despite being a characteristic in analog photography, noise is generally seen as undesirable in digital images, prompting the development of various noise reduction techniques. This research compares manual and artificial intelligence-based methods for noise removal, analyzing their effectiveness across different software. The study examines seven photos with varying noise levels and lighting conditions, using both RAW and JPG formats. Results show that AI-based software offers faster processing, better image clarity, and enhanced detail, offering significant advantages over manual methods. Keywords: digital photography, noise, image processing, artificial intelligence-based techniques 1. INTRODUCTION Image quality is significantly affected by noise, which complicates feature extraction, analysis, recognition, and precise measurements. Noise is inherently present in digital images throughout the processes of capture, en-coding, transmission, and editing. Various fields, including robotics, education, biometrics, medical and biome-dical imaging, remote sensing, security, and surveillance, require clear, noise-free images for accurate proces-sing. Effective noise removal is a complex task that depends on identifying the specific type of noise. Numerous methods have been developed to reduce noise and restore the image to its original quality (Al Mudhafar, 2022) (Owotogbe, 2019). Noise in photographs appears as artifacts that do not originate from the actual scene content. It is one of the un-desirable effects that degrade image quality. A noisy photograph distracts the viewer, drawing attention to grainy areas instead of essential image elements (Image Engineering, 2023). Digital cameras always introduce some degree of noise, but it can be exceptionally low in cameras with larger pixel sizes (pixel pitch ≥ 3 μm) (Imatest, 2023). While signal processing improvements have successfully minimized noise, it remains a challenge in com-pact digital cameras and mobile phone cameras with small pixel sensors. At high ISO values, noise reduction algorithms can cause a visible loss of fine details and textures. Noise is most noticeable in uniform areas of an image and is particularly prominent in darker regions (shadows). It belongs to the category of local quality attributes, meaning that its perception depends on viewing conditions, such as observation distance and image size (DxOmark, 2023). Various types of noise can appear in digital photographs. It can be randomly distributed, exhibit a fixed pattern, or appear as banding lines (Kuzmenko, 2023). Common noise types include Gaussian noise, salt-and-pepper noise, speckle noise, and shot noise (Poisson noise) (Lendave, 2023). When addressing noise removal in digital photography, the most critical distinction is between luminance noise and chrominance noise. Luminance noise is evenly distributed across the image, more visible in darker areas, and easier to remove. Chrominance noise, on 498 29–30 May 2025, Ljubljana, Slovenia the other hand, is more prominent at high ISO values and appears unevenly across the image (Karlović, 2012). Reducing noise in digital images is a challenging task because noise is linked to high-frequency content, such as fine details. The goal is to balance noise suppression while preserving critical image information. Various filtering techniques are commonly used for noise reduction. Noise reduction should ideally be performed before sharpe-ning, and for better results, edge masking and channel-specific noise reduction are recommended. Since noise is typically most dominant in the blue channel, the strongest reduction should be applied there (Wang, 2004). Recently, artificial intelligence-based tools have been developed to effectively recognize noise intensity and au-tomatically remove it while preserving sharp details. These tools present an alternative to traditional noise reduc-tion methods. The aim of this study is to test and compare different software solutions for noise reduction. Some programs require users to manually assess the noise level and adjust the necessary values for optimal correction, while others perform the entire process automatically. 2. EXPERIMENTAL The experimental part of this study consists of comparing the obtained results of noise removal from photographs using manual methods, i.e., applying filters where the user visually assesses the noise level and selects the appropriate correction values accordingly, and AI-based methods through multiple different software solutions to evaluate their capabilities. This is followed by an assessment of the quality of the processed images using metrics, as well as an analysis and discussion of the obtained results. The software selected for testing includes Adobe Photoshop 2021, Adobe Lightroom 2023, DxO PureRAW 3, Luminar Neo, Noiseware, Neat Image, and ON1 NoNoise AI. Photographs with varying content and levels of noise were used to better assess the noise removal capabilities and processing quality of the software. Seven images were selected, differing in content, the amount of noise present, and the lighting conditions during capture. Additionally, the two most common photo formats, NEF (RAW) and JPG, were chosen. Figure 1 presents the photographs used for noise correction in the experi-mental part of the study. Each photograph was first processed in Adobe Photoshop. Both JPG and RAW images were edited using the Reduce Noise filter. The masking capabilities of the software were also analyzed. Based on the amount of noise present, the necessary manual adjustments were selected. Afterward, noise correction was performed in the other listed software, where the automatic correction mode was tested. Adobe Photoshop, Adobe Lightroom, DxO Pur-eRAW 3, Noiseware, and ON1 NoNoise AI offer direct processing of RAW images, while Luminar Neo and Neat Image require prior conversion of RAW images to JPG format. In addition to the visual assessment of the quality of the corrected photographs, the applicability of the SSIM (Structural Similarity Index Measure) metric was examined for monitoring and analyzing noise correction in im-ages (Wang, 2004). The SSIM metric produces both a numerical value and a visual map, indicating areas where greater or lesser differences are present in the images. A comparison was conducted between all corrected imag-es, with each one being compared to every other, resulting in a distance matrix. This matrix can be further utilized for data processing, in this case, Multidimensional Scaling (MDS). 499 29–30 May 2025, Ljubljana, Slovenia Figure 1: Display of photographs used for correction in the experimental part of the study 3. RESULTS Based on the analysis of the obtained samples, we conclude that software, depending on the content of the ima-ges, produces different processing results. Manual processing is most commonly done with software like Adobe Photoshop and Luminar Neo, while automatic processing is handled by software such as Adobe Lightroom, Noi-seware, Neat Image, ON1 NoNoise AI, and DxO PureRAW 3. Satisfactory noise reduction results are provided by ON1 NoNoise AI, Neat Image, and Noiseware for JPG format images, while for RAW format, Neat Image, Adobe Lightroom, and DxO PureRAW 3 stand out. However, some software may also affect other aspects of the photo during reduction, thus altering it. The third example is shown in Figure 2, where it is clearly visible that noise cor-rection in artificial intelligence-based software also applies additional adjustments. In Figure 2 under a), a crop of the original photograph is shown for comparison of the results. In example b), the image processed with the software ON1 NoNoise AI is presented, where during the automatic noise reduction, the software also corrects the color and brightness. In examples c) and d), the noise reduction results are adequate, with the difference being that the software DxO PureRAW 3 lightens the image and makes it cleaner, while the software Neat Image slightly darkens the image but preserves the details. 500 29–30 May 2025, Ljubljana, Slovenia Figure 2: Part of: a) original third photograph and its processing in the software: b) ON NoNoise AI, c) DxO PureRAW 3, and d) Neat Image Based on visual inspection of all seven processed images, DxO PureRAW 3 (for RAW format images), Noisewa-re, and Neat Image deliver the most effective and accurate noise reduction results. All three software programs operate on the principle of artificial intelligence and automatic noise removal, leading to the conclusion that this technology has advanced and surpassed manual noise reduction methods, which require additional time in the photo editing process. AI-based noise reduction software can effectively detect the amount of noise present and remove it while preserving details, which is of crucial importance. In addition to noise reduction, some software also provides additional correction options, including color and brightness adjustments, significantly optimizing the processing workflow and enhancing the overall image quality. Based on the obtained SSIM values, it can be concluded that this metric does not consider only a single quality attribute but, as stated, compares the stru-ctural differences between pixels in the images. For example, when comparing the original photograph with the correction applied in DxO PureRAW 3 (Figure 3), the lowest SSIM value (0.5702) is obtained, even though this correction appears significantly better than that of another software with a higher SSIM value. The differences in characteristics between software solutions, such as DxO PureRAW 3 and other programs, stem from its ability to perform additional automatic corrections, including distortion and brightness adjustments. These corrections are effectively illustrated in the generated structural similarity (SSIM) map, which highlights the significantly enhanced performance of DxO PureRAW 3 compared to other tools. These automatic corrections, in addition to noise redu-ction, were also observed in RAW format images processed with ON1 NoNoise AI and DxO PureRAW 3. Figure 3: The first photograph and its processing in DxO PureRAW 3, compared using the SSIM metric 501 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia dimensions rather than a single expected one. The samples are distributed along the x- and y-axes within the Based on the MDS analysis, it can be concluded that the SSIM values provide a distribution across multiple dimensions rather than a single expected one. The samples are distributed along the x- and y-Based on the MDS analysis, it can be concluded that the SSIM values provide a distribution across multiple such as noise. axes within the range of -1.5 to +1.5, indicating that they cannot be approximated or classified based range of -1.5 to +1.5, indicating that they cannot be approximated or classified based solely on one dimension, solely on one dimension, such as noise. Figure 4 presents the results of the MDS analysis for the first example, where the samples are distributed betwe-Figure 4 presents the results of the MDS analysis for the first example, where the samples are distributed en -2 and +2 on both axes. Additionally, more than two dimensions—quality attributes observed using the SSIM between -2 and +2 on both axes. Additionally, more than two dimensions —quality attributes observed metric—have been identified. using the SSIM metric—have been identified. a) b) Figure Figure 4: 4 : The results of the MDS analysis for the first example The results of the MDS analysis for the first example 4. CONCLUSIONS 4. CONCLUSIONS The analysis of noise reduction capabilities across seven different software solutions on both RAW and The analysis of noise reduction capabilities across seven different software solutions on both RAW and JPG for JPG formats highlights significant differences in performance. AI-based software solutions generally -mats highlights significant differences in performance. AI-based software solutions generally outperform manual outperform manual methods in terms of speed and quality of noise reduction, preserving more image methods in terms of speed and quality of noise reduction, preserving more image details while delivering cleaner details while delivering cleaner results. results. Among the tested software, Neat Image demonstrated exceptional performance in noise removal, while Among the tested software, Neat Image demonstrated exceptional performance in noise removal, while DxO DxO PureRAW 3 provided high-quality results but was limited to RAW format. Adobe Lightroom’s AI-PureRAW 3 provided high-quality results but was limited to RAW format. Adobe Lightroom’s AI-based processing based processing yielded satisfactory results for RAW images but underperformed with JPG images yielded satisfactory results for RAW images but underperformed with JPG images due to manual processing li due to manual processing limitations. Noiseware and ON1 NoNoise AI provided decent noise reduction -mitations. Noiseware and ON1 NoNoise AI provided decent noise reduction but occasionally introduced blurring but occasionally introduced blurring and loss of details. In contrast, Adobe Photoshop and Luminar Neo, and loss of details. In contrast, Adobe Photoshop and Luminar Neo, relying primarily on manual noise correction, relying primarily on manual noise correction, required additional adjustments and filters to achieve required additional adjustments and filters to achieve satisfactory results, making them less efficient compared to satisfactory results, making them less efficient compared to AI-driven alternatives. AI-driven alternatives. The application of SSIM metrics enabled a quantitative assessment of noise correction effectiveness, The application of SSIM metrics enabled a quantitative assessment of noise correction effectiveness, providing providing insights into the differences between processed images. The findings confirm that AI-driven noise reduction methods are more efficient and practical, offering a significant advantage over manual insights into the differences between processed images. The findings confirm that AI-driven noise reduction techniques due to their speed and superior image clarity. methods are more efficient and practical, offering a significant advantage over manual techniques due to their speed and superior image clarity. Future research should focus on improving AI noise reduction algorithms to better balance noise removal Future research should focus on improving AI noise reduction algorithms to better balance noise removal with manual correction workflows could offer enhanced control and flexibility in noise reduction processes. with detail preservation, especially in JPG images. Additionally, exploring the integration of hybrid AI-detail preservation, especially in JPG images. Additionally, exploring the integration of hybrid AI-manual correction workflows could offer enhanced control and flexibility in noise reduction processes. 5. ACKNOWLEDGMENTS This research has been supported by the Ministry of Science, Technological Development and This research has been supported by the Ministry of Science, Technological Development and Innovation (Con University of Novi Sad through project “Scientific and Artistic Research Work of Researchers in Teaching -and Associate Positions at the Faculty of Technical Sciences, University of Novi Sad 2025” (No. 01 5. Innovation (Contract No. 451 ACKNOWLEDGMENTS -03-137/2025-03/200156) and the Faculty of Technical Sciences, tract No. 451-03-137/2025-03/200156) and the Faculty of Technical Sciences, University of Novi Sad through 50/295).-project “Scientific and Artistic Research Work of Researchers in Teaching and Associate Positions at the Faculty of Technical Sciences, University of Novi Sad 2025” (No. 01-50/295). 5 502 29–30 May 2025, Ljubljana, Slovenia 6. REFERENCES Al Mudhafar, R. A. and El Abbadi, N. K. 2022. “Noise in Digital Image Processing: A Review Study.” 3rd Information Technology To Enhance e-learning and Other Application (IT-ELA), Baghdad, Iraq, 2022, pp. 79-84, doi: 10.1109/IT-ELA57378.2022.10107965. Dxomark. What is noise? URL: https://www.dxomark.com/glossary/noise/ (last accessed on 03.07.2023). Image Engineering. Noise. URL: https://www.image-engineering.de/library/image-quality/factors/1080-noise (last accessed on 06.06.2023). Imatest. Noise in photographic images. URL: https://www.imatest.com/support/docs/23-1/noise/ (last accessed on 06.06.2023). Karlović, I., Tomić, I. and Rilovski I. 2012. Digital Rephotography. Novi Sad: Faculty of Technical Sciences, pp. 149-150. Kuzmenko. Understanding Image Noise. URL: https://retouchingacademy.com/qualities-of-digital-images-understanding-image-noise (last accessed on 03.07.2023). Lendave. A Guide to Different Types of Noises and Image Denoising Methods. URL: https://analyticsindiamag.com/a-guide-to-different-types-of-noises-and-image-denoising-methods/ (last accessed on 03.07.2023). Owotogbe, J. S., Ibiyemi, T. S. and Adu, B. A. 2019. “A Comprehensive Review On Various Types of Noise in Image”. Processing International Journal of Scientific & Engineering Research 10 (11), ISSN 2229-5518 Wang Z, Bovik A.C., Sheikh H.R. and Simoncelli E.P. 2004. “Image quality assessment: from error visibility to structural similarity.” IEEE Trans Image Process 13(4):600–612. https://doi.org/10.1109/TIP.2003.819861 ADDITIONAL DATA ABOUT AUTHORS Corresponding author Co-authors Ivana Jurič Ivana Tomić Nemanja Kašiković Trg Dositeja Obradovića 6 Trg Dositeja Obradovića 6 Trg Dositeja Obradovića 6 21000 Novi Sad, Serbia Assoc. Prof. Assoc. Prof. Full Prof. 21000 Novi Sad, Serbia 21000 Novi Sad, Serbia tomic@uns.ac.rs knemanja@uns.ac.rs rilovska@uns.ac.rs +381214852626 +381214852620 +381214852592 Sandra Dedijer Katarina Maričić, Full Prof. TA Trg Dositeja Obradovića 6 Trg Dositeja Obradovića 6 21000 Novi Sad, Serbia 21000 Novi Sad, Serbia dedijer@uns.ac.rs maricic.katarina@uns.ac.rs +381214852623 +381214852592 Magdolna Pal Assoc. Prof. Trg Dositeja Obradovića 6 21000 Novi Sad, Serbia apro@uns.ac.rs +381214852623 503 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION COMPARISON OF SHADOWS CREATED WITH GEOMETRIC PROJECTION, 3D RENDERING AND PHYSICAL EXPERIMENT FOR DIFFERENT PHOTOGRAPHIC LIGHT SOURCES Veronika Štampfl1 and Jure Ahtik1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: In this study, the accuracy of shadows generated by different photographic light sources is evaluated using three methods: geometric projection, 3D rendering and physical experiments. Shadows play an important role in visual perception and are crucial for achieving photorealism in computer graphics, virtual reality and photography. The study uses halogen, LED and xenon light sources, all with and without light-shaping attachments. The geometric projection defines fully, partially and non-illuminated areas based on the light source geometry, but neglects material properties. 3D rendering using Elixxier set.a.light 3D software computationally simulates light dispersion, while physical experiments provide real-world validation. The comparative analysis focusses on shadow harshness and fidelity. The results show that no single method is universally accurate, with physical experiments providing the most reliable reference. The results contribute to the improvement of shadow rendering algorithms and the enhancement of visual realism in digital applications. Keywords: geometrical shadow projection, shadow rendering, photographic light sources, light harshness 1. INTRODUCTION Shadows are a fundamental aspect of visual perception. They are created when an object obstructs a ray of light and prevents it from reaching a projection surface. The resulting shadow contains valuable information about the properties of the object, the light source and the projection surface, provided that two of these three properties are known. Shadows are not just the absence of light; they are dynamic entities that can reveal intricate details about the scene in which they are located. In art, shadows and the contrast they create with light are often used to evoke certain visual effects, commonly referred to as “creating a mood” (Buryk and Bratitsel, 2024). Beyond their artistic applications, shadows play a crucial role in the visual understanding of object shapes, surface properties and spatial positioning within images (Corpon, 1962). The study of shadows extends beyond the realm of art and into the domain of science and technology, particularly in computer graphics and virtual environments. Achieving photorealism in virtual environments is a complex task that requires the accurate simulation of light and shadow. Shadows are essential for creating a sense of depth and realism in rendered scenes, and their accurate representation is crucial for applications ranging from video games to architectural visualisation and virtual reality. For this reason, shadows have been studied extensively, with a particular focus on improving the quality of rendered shadows to ensure they closely resemble real-world shadows (Osti et al., 2019). In the past, early algorithms for shadow rendering relied on geometric projection methods that were limited to uniform projection planes. While these methods were computationally efficient, they often failed to capture the complexity of real-world shadows, especially in scenes with complicated geometries and varying material properties. Over time, more advanced techniques, such as shadow volumes, have been developed to overcome these limitations. Shadow volumes take into account the complexity of the scene and the material properties of objects, resulting in a more accurate shadow rendering (Liu, 2009). However, these methods are computationally intensive, and researchers continue to seek a balance between the quality of shadow rendering and the computational resources required to achieve it (Sattler et al., 2005). 504 29–30 May 2025, Ljubljana, Slovenia Despite significant advancements in shadow rendering algorithms, no single method has achieved universal accuracy in all contexts. Various algorithms have been proposed to represent shadows as realistically as possible, each with its strengths and limitations (Hasenfratz et al., 2003). For example, some methods excel in rendering hard shadows with sharp edges, while others are better suited for soft shadows with gradual transitions between light and dark regions. The challenge is to develop algorithms that can accurately simulate the wide range of shadow types that can be observed in the real world scenarios, from the sharp shadows cast by a point light source to the soft, diffused shadows created by large, area light sources (Ritschel et al., 2009). This study aims to evaluate the accuracy of shadows generated by different photographic light sources using three distinct methods: theoretical (geometric projection), virtual (3D rendering) and experimental (physical experiment). Each method offers a unique approach to shadow generation, and by comparing their results we can gain insight into the strengths and limitations of each technique. Various light sources are used in the study, including halogen, LED and xenon, all with and without light-shaping attachments such as softboxes. These attachments are designed to modify the properties of the light beam, resulting in shadows with different characteristics. In the first method, geometric projection, the shadow areas are calculated based on the geometry of the light source and the occluding object. This approach defines areas of full illumination, partial illumination (penumbra) and complete shadow (umbra). While geometric projection provides a straightforward and computationally efficient method for generating shadows, it often overlooks the material properties of the light source and its attachments, which can significantly affect the accuracy of the resulting shadows (Štampfl & Ahtik, 2024). For example, the use of a softbox can scatter the light and create softer shadows with less defined edges, a phenomenon that the geometric projection may not fully capture. In the second method, 3D rendering, the shadows are simulated in a virtual environment using specialized software. In this study, we use the Elixxier set.a.light 3D software, which was specially developed for the high-precision creation of photo scenes with predefined light sources. This software uses complex algorithms to realistically simulate the behaviour of lighting technology, including the dispersion of light and the interaction between light and objects. The virtual environment allows for precise control over lighting conditions and enables the generation of shadows that are very similar to those in the real world scenarios. However, the accuracy of these shadows depends on the accuracy of the software’s algorithms and the quality of the input data, such as the properties of the light sources and the materials of the objects in the scene. (Elixxier, 2024) In the third method, the physical experiment, the shadows are captured in a real photo studio environment. This approach provides a ground truth against which the results of the geometric projection and 3D rendering methods can be compared. The experimental setup includes a variety of light sources and light-shaping attachments, allowing for the generation of shadows with different properties. By capturing these shadows using a high-resolution camera, we can analyse their properties and compare them to the shadows generated by the other two methods. The images from all three methods — geometric projection, 3D rendering and physical experiment — are analysed for their shadow properties. A comparative evaluation of shadow quality allows us to assess the accuracy of each method in simulating realistic shadows under different lighting conditions. This analysis includes both visual and numerical assessments of shadow harshness , a metric that quantifies the sharpness or softness of shadow edges (Štampfl & Ahtik, 2024). By examining the differences in shadow harshness between the three methods, we can identify areas where improvements in shadow rendering algorithms are needed. 2. EXPERIMENTAL We have created three sets of six images, each set corresponding to one of the analysed imaging methods: geometric projection, 3D rendering and a physical experiment. The six images within each set represent three different light sources – halogen, LED and xenon, used once without and once with a light-shaping attachment designed to soften the original light beam. 2.1 Generating shadowed images To obtain shadows produced by different light sources, we applied a method proposed in our previous research (Štampfl and Ahtik, 2024). This involves using a 50 × 50 cm grey plane with ArUco markers as a projection plate 505 29–30 May 2025, Ljubljana, Slovenia and placing a 6 × 8 cm vertical plane as an occluder, which produces a shadow when illuminated with a light source placed 120 cm away and 10 cm above the origin of the plane. The setup can be seen in Figure 1, which also shows a camera mounted above and perpendicular to the projection plane, capturing the shadow. We have followed the geometry of the setup in all three approaches to image generation. Figure 1: Shadow capture method in 3D environment and physical experiment. The setup in Figure 1 was set up in a photographic studio with a black background to minimise the ambient reflections of the positioned light source. We used a Nikon D850 DSLR camera in manual mode with a Nikkor 50 mm/1.8 lens. The aperture was set to f/5.6 to maximise the sharpness of the lens. For the virtual environment, we used the Elixxier set.a.light 3D software (version 2.5), which was specially developed to mimic photo studio conditions and can be controlled in the same way. The projection plane and occluder were imported as 3D objects created in Blender software (version 2.91.2) and placed into the scene to scale. A 50 mm lens was also used here to render the image. For the theoretical shadows, we used Adobe Illustrator (version 29.0.1) to create vector images of the geometric projections, taking into account the geometry of the entire scene. 2.2 Light source properties Three light sources were analysed in two different setups – with and without a light-shaping attachment. The light sources were first determined according to their availability for the physical experiment and then matched with the available light sources in the 3D environment. For the geometric projections, we used the exact geometry of the light sources and light-shaping attachments from the physical experiment. We used a Kaiser Studiolight H with a halogen bulb with a diameter of 2 cm as the halogen light source for the experiment. To soften the original light beam, we used a square softbox with a side length of 70 cm and a depth of 45 cm. In 3D, we used a Godox AD 200 Pro with a bare bulb, while adding a softbox with the same side dimensions but 35 cm deep. For the LED light source, we used a square Lupo Superpanel dual-colour LED panel with 30 cm sides. A softbox with a depth of 30 cm and a side length of 40 cm was used as a light-shaping accessory. As no identical light source was available in the 3D programme, we used an Arri S30-C LED panel measuring 35.5 × 30 cm, with the side barndoors set to −5° and the top and bottom barndoors set to 0°. To soften the light, there was again no attachment available. We therefore moved the light source 30 cm closer to the scene and adjusted the side flaps of the barndoors to 10° and the top and bottom flaps to 5°, which corresponded to the final dimensions of the physical light shaper. For the xenon light source we used an Elinchrom ELC PRO HD 500 flash unit with a 7 cm diameter bulb. The light was attenuated by a square softbox with a side length of 66 cm and a depth of 35 cm. In the virtual environment, we used a 500Ws flash unit with a light bulb and a square softbox with a side length of 60 cm and a depth of 32 cm. 506 29–30 May 2025, Ljubljana, Slovenia 2.3 Image processing Three shadow generating techniques and six light source combinations resulted in 18 test images. Each scene was also captured without an occluder, resulting in an image without shadows that allowed us to remove the background from the virtual and experimental images. To ensure comparability, we used code written in the Python programming language to first register all 32 images to the reference image using the ArUco markers on the projection plane. We then cropped them to the same area to make the image processing less computationally demanding but retain the shadow information. In the next step, we subtracted the shadowed image from its non-shadowed pair, while the resulting image was inverted to show the positive shape of the shadow. For visual analysis, we equalized the inverted shadow images to avoid the contrast effect on our visual perception of shadow harshness. These images were then analysed using the harshness method proposed in our previous study (Štampfl and Ahtik, 2024). First, we thresholded each image and determined the centroid of the most prominent shape at each threshold. The centroid coordinates for all 256 thresholds per image were then combined into datasets that were denoised and plotted to check for possible errors. The derivatives for each dataset were calculated and the breakpoint between umbra and penumbra was determined. In this way, the height of the umbra and the width of the penumbra were determined and the final harshness H calculated. 3. RESULTS AND DISCUSSION The obtained results are divided into two sections. The first section, the visual analysis, examines the final equalized images visually, describing and comparing the umbra and penumbra shapes among the three approaches used for generating shadows. The second section, the numerical analysis, evaluates the results obtained from shadow harshness determination using a previously proposed method. 3.1 Visual analysis In Table 1, equalized shadow images are presented for the three tested light sources with and without the light-shaping attachment in place. The image of geometric projection can be compared to the 3D rendered version and from the real-life studio experiment. In general, we can observe a great deal of resemblance between the three corresponding images, apart from the high amount of noise in the areas of full illumination for 3D and experimental images, suggesting that the selected light sources had an adequate level of resemblance within 3D and real-life environment. 507 29–30 May 2025, Ljubljana, Slovenia Table 1: Equalized shadow images for all six light sources from geometrical projection, 3D rendered shadows and shadows from experiment. Without light shaper With light shaper Projection 3D Experimental Projection 3D Experimental Halogen LED Xenon When analysing the images from each of the six light source combinations, we can see a similar but not identical shadow rendering when comparing the three methods. In the cases where the differences occur between the geometric projection and 3D or 3D and experimental images, this could indicate that the light sources used in both approaches were not similar enough, while it is possible that it indicates a generally different shadow rendering due to the method. Comparing the three images from geometric projection and different light sources without a light-shaping attachment, it is clear how the size of the light source affects the ratio of umbra to penumbra. Halogen has the widest umbra, which remains the same width across almost the entire y-axis. This is due to the size of the light source, as the bulb has a diameter of 2 cm. This is followed by xenon with a bulb of 7 cm in diameter, which results in umbra that becomes narrower in the upper area (y=0). This is due to the wider source point, which begins to 508 29–30 May 2025, Ljubljana, Slovenia cross-illuminate the region. This becomes particularly clear when comparing the described images with the image for the LED light source, where the umbra width reduces almost to zero, which is due to a much wider light source. In these cases, the width of the penumbra is in inverse proportion to the width of the shadow, as it is largest in the upper part of the image for the LED light source and smallest for the halogen lamp. The relationship between projected and 3D shadows is identical for halogen and LED, with only a slight difference in harshness of the transition between umbra and penumbra and from penumbra to fully illuminated surface. On the other hand, xenon in 3D is identical to the halogen pair and not to its geometric projection. This would lead us to believe that the xenon light source in 3D does not match the experimental version. However, if we compare them with the experimental shadow, they are again identical, but with an additional softness at the transitions in the shadow regions. On the other hand, the experimental shadow for halogen differs from its pair for projection and 3D, as it shows no penumbra at all and acts entirely as a point source, while the LED samples can be treated as identical, but with a difference in the harshness of the transitions. This shows that the geometric projection for simple light sources is not always completely accurate, especially in cases with pulsating light (xenon) or with a light source smaller than the occluder (halogen). In practise, the latter act as a pure point light source so that no penumbra is created. These differences are also realised in the 3D environment, where the ray tracing takes over both real scenarios, but still relies on the basic geometry. The halogen example is misinterpreted as a point source, while pulsating light and continuous sources such as in the LED example are displayed correctly. The statement regarding the tested 3D environment, which uses both real-life situations and geometric projections to achieve a balance between physical accuracy and fast real-time visualisation, becomes particularly clear when comparing the three images for halogen and xenon light source with a light-shaping attachment. The 3D version generally appears as soft as its experimental pair, but the transitions are not as smooth, with quadrilateral shapes clearly visible in the penumbra. Interestingly, this is not visible in the combination for LED, which we believe is due to the fact that no light shaper was actually in place, as we only adjusted the positioning and size of the light source to match the experimental version with a light shaper. This leads us to the conclusion that both the geometric projection and 3D rendering approaches struggle to visualise softened shadows accurately, especially due to the complexity of penumbra rendering. 3.2 Numerical analysis – harshness Figure 2 shows the results of harshness H for all three shadow rendering approaches. As described in previous research (Štampfl and Ahtik, 2024), the geometric projection is insufficient, especially when visualising softer shadows. With a visual analysis, we have shown that 3D rendering also lacks precision when light-shaping attachments are applied to the original light source, in our case softboxes. These difficulties also carry over to the harshness values, where the results are similar for light sources without light-shaping attachments, while they differ in value and tendency when comparing the combinations with attached attachments. Figure 2: Harshness H for shadows from geometrical projection (proj), 3D environment (3d) and experiment (exp) for halogen (_HAL), LED (_LED) and xenon (_XEN) light sources with (_s) and without a light-shaping attachment. For light sources without light-shaping attachments, the results are thus similar for all three approaches, while the harshness of the experimental shadows is always the lowest of the three results: for halogen, H , H and H are proj 3d exp 0.04, 0.05 and 0.02, for xenon 0.10, 0.10 and 0.06 and for LED 0.37, 0.36 and 0.31. These results are consistent with the visual assessments, where the shadow harshness is visually the same for halogen and xenon, while it is much softer for LED. 509 29–30 May 2025, Ljubljana, Slovenia When you add a light-shaping attachment, the differences in harshness for the three shadow rendering approaches tested no longer follow the observed trend. The results of H , H and H for LED_s are 1.11, 0.60 and 0.43, proj 3d exp which is still the lowest harshness for the experimental shadow but the highest for the geometric projection. On the other hand, HAL_s and XEN_s show the lowest harshness for the 3D rendered shadow ( H is 2.49 and 1.41, 3d respectively), while H is higher in both cases (H is 3.75 and 1.73, respectively), but not the highest for XEN_s. exp exp These inconsistent differences not only demonstrate again the complexity of rendering soft shadows, but also test the robustness of the harshness determination method for such light sources. Figure 3 shows the data sets of centroid coordinates for each light source, both for the examples from the 3D rendering and for the experiment. For a better understanding of the data, they are superimposed on an image of the experimental shadow. It is clear that the data sets for light sources without a light-shaping attachment match regardless of the method used (3D or experimental), while the other three data sets (_s) show larger offsets or completely different trends. While the differences for LED_s and XEN_s are mostly only seen in the offset, HAL_s shows a different trend in the generated penumbra region. This could indicate that inaccurate penumbra generation in 3D is in comparison to the experimental approach also the reason harshness result for the 3d_ HAL_s sample does not match the trend shown by the other 3D and experimental pairs. Figure 3: Data sets of centroid coordinates (x,y) during harshness determination, which numerically indicate the differences in shadow generation between 3D rendering and experimental method. 4. CONCLUSION This study provides a comparative evaluation of shadows generated by geometric projection, 3D rendering and physical experiments under different lighting conditions. The results highlight the strengths and limitations of each method, emphasising that while geometric projection is computationally efficient, it often fails to capture the complexity of real-world shadows, particularly when light-shaping attachments are involved. 3D rendering, on the other hand, offers a high degree of control and precision, but is dependent on the accuracy of the underlying algorithms and input data. Physical experiments serve as a valuable reference as they provide the most reliable representation of shadows in the real world. The results show that no method of artificial representation is universally accurate. Geometric projection provides a basic approximation but is not accurate enough in complex scenarios, while 3D rendering, while promising, requires algorithmic refinements to better simulate soft shadows and varying light intensities. The experimental approach remains the benchmark for assessing shadow realism, offering crucial insights for improving virtual shadow generation techniques. 510 29–30 May 2025, Ljubljana, Slovenia This research contributes to ongoing efforts to improve the accuracy of shadows in digital environments. By refining 3D rendering algorithms and integrating experimental findings, future developments can improve photorealistic shadow rendering in computer graphics, virtual reality and cinematography. These findings will help optimise computational efficiency while maintaining high visual fidelity, benefiting a range of industries that rely on realistic shadow rendering. 5. REFERENCES Buryk, R. and Bratitsel, M. 2023. “Harmony of Light and Shadow: Key Aspects of Lighting in Portrait Photography.” Scientific Journal of Polonia University 61 (6): 38–49. Corpon, C. 1962. Light as a Creative Medium. Art Education 15 (5): 4–7. Eisemann, E., Schwarz, M., Assarsson, U., and Wimmer, M. 2011. Real-Time Shadows. AK Peters/CRC Press. Elixxier Software. set.a.light 3D – Lighting Simulator for photographers & filmmakers. URL: https://www.elixxier.com/en/set-a-light-3d/ (last sccessed on 31. 1. 2025). Hasenfratz, J., Lapierre, M., Holzschuch, N. and Sillion, F. 2003. “A Survey of Real‐time Soft Shadows Algorithms.” Computer Graphics Forum 22 (4): 753–774. Liu, N. and Pang, M. 2009. “A Survey of Shadow Rendering Algorithms: Projection Shadows and Shadow Volumes.” Second International Workshop on Computer Science and Engineering, 488–492. Osti, F., Santi, G. and Caligiana, G. 2019. “Real Time Shadow Mapping for Augmented Reality Photorealistic Rendering.” Applied Sciences 9 (11): 2225. Ritschel, T., Grosch, T., and Seidel, H.P. 2009. “Approximating Dynamic Global Illumination in Image Space.” ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games, 75-82. Sattler, M., Sarlette, R., Mücken, T. and Klein R. 2005. “Exploitation of human shadow perception for fast shadow rendering.” In Proceedings of the 2nd symposium on Applied perception in graphics and visualization (APGV ‘05), 131–134. New York: Association for Computing Machinery. Štampfl, V. and Ahtik, J. 2024. “Shadow Segmentation with Image Thresholding for Describing the Harshness of Light Sources.” IEEE Transactions on Image Processing 33: 3428–3440. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Veronika Štampfl Jure Ahtik Chair of Information and and Graphic Arts Technology Graphic Arts Technology Faculty of Natural Sciences Faculty of Natural Sciences and Engineering and Engineering Graphic Arts and Design, Graphic Arts and Design Chair of Information Department of Textiles, Department of Textiles, University of Ljubljana University of Ljubljana Aškerčeva 12 Aškerčeva 12 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia 01/200 32 86 jure.ahtik@ntf.uni-lj.si 01/200 32 46 veronika.stampfl@ntf.uni-lj.si 511 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION REFLECTANCE SPECTRA RECONSTRUCTION FROM FLATBED SCANNER-BASED RGB VALUES USING ARTIFICIAL NEURAL NETWORK Mihael Lazar1 and Aleš Hladnik1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Spectral description of colours using multi or hyper-spectral cameras is costly. Thus, algorithms for mapping RGB images captured with cheaper commercial cameras into spectral data are being developed. A straight mathematical approach for spectral reconstruction is not feasible if capturing conditions and camera cha-racteristics are partially unknown. Our approach proposes to capture RGB values of a colour patch reference set with known spectral values in the same acquisition conditions as the image of interest and train the single-layer artificial neural network using Matlab with Levenberg-Marquardt and a faster scaled conjugate gradient learning algorithms varying the hidden layer neurons number to perform RGB to spectrum mapping. Images obtained with a flatbed scanner avoid the problem of uneven illumination and lens-related geometric and refractive distortions using cameras and expand the possibility of capturing in more expansive ProPhoto colour space and 16-bit reso-lution compared to the Adobe RGB 8-bit capturing utilised in our previous work. Keywords: spectral reconstruction, flatbed scanner, artificial neural networks 1. INTRODUCTION A multispectral or, even better, a hyperspectral camera can be applied to describe colour images with spectral data (Cucci 2019) instead of RGB values captured by a commercial or professional camera. As such devices are costly, they are only found in better-equipped laboratories and professional applications. Capturing colour images with an RGB camera is significantly cheaper, and active research is underway to develop algorithms for mapping RGB into spectral values (Slavuj 2013, Cao 2017, Zhao 2020). The reconstruction of reflectance spectra (hereafter RS) from RGB values is mathematically feasible if the light source’s properties, the imaging device’s optical properties, and its sensors’ characteristics are known. If any of this information is unknown, the information for the mapping must be obtained in other ways. Our approach pro-poses to capture, in addition to the images, the RGB values of a set of colour patches whose RS are known and to teach an artificial neural network (hereafter ANN) to map their colours to RS using a learning set (hereafter LS) of RGB-reflectance spectrum pairs. When capturing images with a commercial camera, as discussed in our previous work (Lazar 2019, Lazar 2022), it is necessary to ensure uniform and time-invariant illumination and to perform geometry and spherical aberration correction before further processing. For this reason, we have chosen to use a flatbed scanner instead of a com-mercial camera in this study, where uniform illumination and the absence of geometric and refractive distortions due to lenses are guaranteed. Matlab offers a range of different learning algorithms for modelling ANNs. Specifically, for the function approx-imation, Matlab’s Deep Learning Toolbox module offers a choice between a faster scaled conjugate gradient backpropagation (hereafter BP) learning algorithm that can harvest the parallel computing power of the Graphics Processing Unit (GPU) and a slower Levenberg-Marquardt (hereafter LM) learning algorithm that, although only executed on the CPU, converges faster and finds more efficient models. In previous research, we have observed the dependence of the performance of the models on the size of the LS since when retrieving images with a camera, it is necessary to capture a reference set of colour samples of a suitable (smaller) size under the same 512 29–30 May 2025, Ljubljana, Slovenia lighting conditions, ideally simultaneously. When using a scanner, simultaneous acquisition of the image and the reference set is not necessary, so only two learning sets with a larger number of colour patches were used in our study. For modelling, single-layer ANNs were applied, which, according to the results of our previous studies, were modelled within a modified range of the number of neurons in the hidden layer. The flatbed scanner allows the description of colours in different colour spaces, where we used Adobe RGB (1998) and the more extensive ProPhoto RGB, and 16-bit RGB readings in addition to 8-bit ones. In the experiment, the influence of different parameters on the performance of the ANN models was monitored, and the performance of the scanner-based modelled ANNs was additionally compared with the performance of camera-based ANNs modelled in our previous experiments (Lazar 2020, 2022) using learning sets with RGB values of three commercial cameras. Our hypotheses in this study are as follows: 1. RS reconstruction from RGB values of the scanned image is feasible. 2. RS reconstruction from a scanned RGB image will outperform that from an RGB photograph. 3. RS reconstruction from an image at 16 bits per colour channel will perform better than that at eight. 4. RS reconstruction from an image scanned in ProPhoto will be better than from an image scanned in Ado- be RGB colour space. 5. ANN models for RS reconstruction trained with the LM algorithm will perform better than those trained with the BP algorithm. 6. ANN models for RS reconstruction learned on a larger training set will perform better than models learned on a smaller one. 2. EXPERIMENTAL Our study focuses on the reconstruction of reflectance spectra from RGB flatbed scanner readings by supervised learning of a single-layer ANN implemented with the Matlab Neural Network Toolbox on a general-purpose PC. In the ANN model learning, the inputs are RGB values of the scanner readings, and the outputs are vectors of spectral reflectance components - the spectrophotometer readings. As a source of colourimetric data, we used The Munsell Book of Color Matte Collection with 1301 colour samples of different chroma, value and hue values, which also include natural colours such as earth, skin, foliage and a set of neutral tones. The 40 sheets are divided into a 2.5-step Munsell hue circle (2.5; 5; 7.5; 10 for R, YR, Y, GY, G, BG, B, PB, P and RP), with an additional four sheets containing neutral tones and lightly tinted greys. Each patch was measured with an X-Rite i1Pro 2 spectrophotometer at five points (near the corners and at the centre of the patch), and RS vectors with 107 components were obtained at wavelengths from 376,66 to 730 nm in steps of 3,33 nm, with a maximum standard deviation for the five measurements of less than 0,4 %. Averages were calcu-lated from the five measurements on the patch, and the RS was subsampled to 36 components from 380 nm to 730 nm in steps of 10 nm. The sheets of the Munsell Matte Collection were scanned at 300 DPI using an Epson Perfection V750 Pro flat-bed scanner with manual settings, i.e. filters, sharpening, and corrections turned off. Each sheet of samples was captured in 24 and 48-bit RGB mode, i.e. with 8 and 16 bits per channel, and in Adobe RGB and ProPhoto RGB colour space. The median RGB values of each colour patch were obtained on the inner 50% square of the patch. The complete set consisting of RGB-reflectance pairs for all 1301 Munsell Matte patches was assembled, with three RGB values and 36 values for each reflectance spectrum. Two learning sets were formed before training a series of ANNs through a supervised learning algorithm - the subset of 90% and 50% of a complete set. The learning set was randomly partitioned into training, validation and test sets in a 70:15:15 ratio before every ANN model training. ANN learning algorithms search for the minima of a cost function, which may be global or local. Therefore, trai-ning was repeated 21 times for each combination of ANN parameters to find the best-performing models, varying the size of the hidden layer from 18 to 75 neurons in step 3. The odd number (21) was chosen to compute some additional statistics not mentioned in the paper. The calculations for both learning algorithms (BP and LM) were performed for two training set sizes (650 and 1711 RGB-RS pairs), with colour readings in two colour spaces (ProPhoto and Adobe RGB) and with 8 and 16-bit precision. Data on the best results and averages were collected, and the results were compared and visualised. Almost 80 hours of 6-core CPU parallel processing time and more 513 29–30 May 2025, Ljubljana, Slovenia than 4 hours of GPU time were spent. The Matlab Parallel Computing Toolbox supports CPU parallel computing. ANN modelling on all CPU cores was activated using the useParallel training option. 3. RESULTS WITH DISCUSSION In our experiment, as the number of hidden layer neurons increased from 18 to 75 in step 3 for both ANN learning algorithms, we monitored the training time, the number of epochs, i.e. the number of repeated learning cycles with the whole LS, and the time required per single epoch (Figure 1), and in particular, we compared the average and best MSE performances of the RS reconstruction utilising ANN models. (a) (b) Figure 1: Average training time, average time for a single epoch and average number of epochs used to train an ANN with a larger LS of 1171 RGB16 ProPhoto input values using LM (a) and BP algorithm (b) When scanning colour images with a flatbed scanner, the illumination is provided by a smoothly moving array of calibrated LED lamps, which ensures uniform illumination along the entire image acquisition, whereas a commer-cial camera captures the whole image simultaneously, but it is more difficult to ensure uniform illumination due to shadows, reflections and, e.g. in the case of spotlights, the uneven distance between the lamp and the surface. Therefore, a comparison was made between the RS reconstruction efficiencies of ANNs modelled with RGB data from three commercial cameras used in previous studies and ANNs modelled with 8- and 16-bit RGB input read-ings from a flatbed scanner for both modelling algorithms, two LS sizes and the ProPhoto and Adobe RGB colour spaces. Some of the 16 combinations are shown in Figure 2 to Figure 5. (a) (b) Figure 2: Comparison of test set mean (a) and best (b) MSE performance of ANNs modelled with LM algorithm, large LS (1171), and RGB8 AdobeRGB data of three commercial cameras versus RGB16 ProPhoto data of V750 scanner 514 29–30 May 2025, Ljubljana, Slovenia (a) (b) Figure 3: Comparison of test set mean (a) and best (b) MSE performance of ANNs modelled with BP algorithm, medium LS (650), and RGB8 AdobeRGB data of three commercial cameras versus RGB8 ProPhoto data of V750 scanner (a) (b) Figure 4: Comparison of test set mean (a) and best (b) MSE performance of ANNs modelled with LM algorithm, medium LS (650), and RGB8 AdobeRGB data of three commercial cameras versus RGB8 AdobeRGB data of V750 scanner (a) (b) Figure 5: Comparison of test set mean (a) and best (b) MSE performance of ANNs modelled with BP algorithm, large LS (1171), and RGB8 AdobeRGB data of three commercial cameras versus RGB16 AdobeRGB data of V750 scanner 515 29–30 May 2025, Ljubljana, Slovenia In addition to comparing the performance of ANNs for reconstructing RSs trained with RGB values captured by the camera and the scanner, we were also interested in the performance of models trained with the LS of samples captured by the scanner alone, observing four variables, namely the influence of bit depth, the extent of the colour space, the choice of the learning algorithm, and the size of the LS, as described below. Assuming that a larger bit depth will improve the performance of the ANN models, we compared the models trained with 8- and 16-bit RGB data, observing both average and best performances when training with LM or BP algorithms, two LS sizes and two colour spaces. The comparison shows a slight improvement when using 16-bit RGB values only when observing the best performances of the models with the LM algorithm and scanning in the ProPhoto space. The improvement is not pronounced, as the performances overlap in places, and it is only noticeable when comparing linear approximations (Figure 6). In all other cases, i.e. when modelling with the BP algorithm in ProPhoto space and with both algorithms in Adobe RGB colour space, the performances overlap significantly. Examples of overlapping results for the 8- and 16-bit models are shown in Figure 7. (a) (b) Figure 6: Comparison of RGB8 vs RGB16 test set best MSE performance of ANNs modelled with LM algorithm, V750 scanner ProPhoto large (a) and medium LS (a) (a) (b) Figure 7: Comparison of RGB8 vs RGB16 test set best MSE performance of ANNs modelled with V750 scanner ProPhoto RGB medium LS and BP algorithm (a) and Adobe RGB large LS and LM algorithm (b) A professional scanner allows for capturing colours in the larger ProPhoto colour space and in the slightly nar-rower Adobe RGB colour space (#image of both colour spaces). As the performance of models trained with input values captured in the larger colour space was expected to be better, a comparison of the performance of the models trained with RGB values described in the two selected spaces was made. Figure 8 shows the overlapping performance of the models both when trained with BP, 8-bit depth and smaller LS, and when trained with LM, 16-bit depth and larger LS. 516 29–30 May 2025, Ljubljana, Slovenia (a) (b) Figure 8: Comparison of ProPhoto vs AdobeRGB test set best MSE performance of ANNs modelled with V750 scanner RGB16 large LS and LM algorithm (a) and RGB8 medium LS and BP algorithm (b) When modelling ANNs for function approximation, we compared the performance of the models trained by the two algorithms at both bit depths, colour spaces and LS sizes. Comparisons of the best performances between LM and BP models at large learning sets, 16-bit resolution, and ProPhoto colour space, and at smaller learning sets, 8-bit resolution and Adobe RGB space, are shown in Figure 9. (a) (b) Figure 9: Comparison of LM vs BP algorithm test set best MSE performance of ANNs modelled with V750 scanner ProPhoto RGB16 large LS (a) and Adobe RGB8 medium LS (b) When training ANNs, building a sufficiently large LS is necessary to ensure adequate model reconstruction perfor-mance and, therefore, to capture a sufficient number of reference colour samples. In our study, we monitored two sizes of the LS, a smaller one with 650 and a larger one with 1171 colour samples. A comparison of the average performances of the two sizes of the LS for ANNs modelled with BP and 8-bit RGB readings in the ProPhoto co-lour space and the best performances of the two sizes of the LS for models with LM, 16-bit resolution in the Adobe RGB space is shown in Figure 10. 517 29–30 May 2025, Ljubljana, Slovenia (a) (b) Figure 10: Comparison of Large vs medium LS best test set MSE performance of ANNs modelled with V750 scanner ProPhoto RGB8 and BP algorithm (a) and Adobe RGB16 values and LM algorithm (b) 4. CONCLUSIONS As the number of neurons in the hidden layer increases, the complexity of the model - the number of synapses - increases linearly according to the formula (N + N ) * N , where N is the number of input neurons, N is the i o h i o number of output neurons and N is the number of neurons in the hidden layer. At the same time, as the capacity to h accumulate “knowledge” increases, the learning time also increases linearly. As the number of neurons increases, the number of epochs, i.e. the ANN learning cycles with the whole LS, decreases in the LM algorithm, and the time for each epoch increases. In the BP algorithm, however, as the number of neurons increases, the number of epochs increases, and the time to learn each epoch is almost constant. Most MSE performance comparisons of the ANN models trained with the scanner RGB readings and the RGB readings from the three cameras show an improvement in both the average and best performances when using the scanner. The improvement in performance using the scanner is noticeable for both learning algorithms and is more prominent for the larger LS. When observing the average performances of the ANN models trained with the smaller LS of scanned RGB readings, there is a partial overlap with the best performances of the ANN models trained with the RGB readings of the Nikon D600 camera. However, the best MSE performances of the former are still noticeably better than those of the models using cameras, which confirms our second hypothesis and, consequently, our first hypothesis. From the overlap of the MSE performance of the 8- and 16-bit models, we can conclude that a larger bit depth for both ANNs trained with BP and ProPhoto RGB input values and for both algorithms and Adobe RGB input values does not help to improve the performance of the ANN models for the reconstruction of the reflectance spectrum. A partial improvement is only observed when modelling the ANN with the LM algorithm and the LS of values de-scribed in a more extensive colour space. The third hypothesis regarding the performance improvement of ANN models trained with a LS of 16-bit RGB input values compared to 8-bit is thus only partially confirmed. Despite the expectation that models trained with colour values scanned in the ProPhoto RGB space will perform better than those scanned in Adobe RGB, the MSE performances of the two overlap significantly. The difference in performance is probably not pronounced because most of the colour samples are within the range of the Adobe RGB space, and the colours of the learning sets are adequately described in both cases, leading to compara-ble performance of the two types of models. The fourth hypothesis that the reconstruction of RS from an image scanned in the ProPhoto colour space will be better than one scanned in the Adobe RGB space has not been confirmed. As shown in our previous experiments with AdobeRGB colour space and 8-bit resolution photos, even when using a scanner to capture the input colour values, the ANN models trained with the LM algorithm outperform the BP models for all combinations of the observed parameters. The linear approximation of the average and best ANNs performance ranges from 50% better performance for LM models with fewer neurons to 20% better for the largest observed number of neurons, confirming our fifth hypothesis. 518 29–30 May 2025, Ljubljana, Slovenia As the number of colour samples increases, the LS increases, and so does the amount of knowledge the ANN absorbs. In previous research, due to the aim of capturing reference samples with the camera in a practical way, we have observed the impact of several different sizes of the LS, ranging from the smallest, with 195 samples, to the largest, with 1171 samples. When capturing images with the camera, a set of reference samples must be captured in parallel each time due to the variable illumination. This is unnecessary for scanner image capture, as the reference samples are captured only once. The best ANN is found and then used to reconstruct the RS from the scanned RGB values over a longer period of time. Therefore, it makes sense to use a larger LS here, and we chose to compare the training performance with a medium-sized one with half of the total available Munsell Matte Collection colour samples and a LS that includes 90% of the samples. As expected, the learning performance with the more extensive LS is noticeably better. Comparison of the linear approximation of the mean MSE performance values shows an improvement between 10% and 25% with the larger LS, while the improvement when observing the best MSE performance is smaller but still reaches up to 20%, confirming our sixth hypothesis. Finally, it can be said that the reconstruction of RS from scanned images using ANN is feasible, so our first hypothesis was confirmed as well. It is comparable and even superior to the performance of RS reconstruction from camera images, both in terms of improved results and ease of implementation. Due to the constant illumination, ANN modelling and best-fit model search only need to be performed once, unlike camera image acquisition, where the lighting conditions may change with each acquisition. The use of a good quality scanner, therefore, allows successful reconstruction of the RS, but the question is whether the performance would also be adequate, e.g. using a cheaper flatbed scanner for home use or perhaps a scanner in a multifunction photocopier, which may be the subject of further research. 5. REFERENCES Cao, B., Liao, N., Cheng, H. 2017 “Spectral reflectance reconstruction from RGB images based on weighting smaller color difference group.” Color Research & Application 42(3): 327-332. Cucci, C., Casini, A. 2019. “Hyperspectral imaging for artworks investigation.” Data Handling in Science and Technology” 32: 583–604. Lazar, M., Javoršek, D., Hladnik, A. 2020. “Study of camera spectral reflectance reconstruction performance using CPU and GPU artificial neural network modelling.” Tehnički Vjesnik, 27: 1204–1212. Lazar, M., Hladnik, A. 2022. “Exploiting Nonlinearity between Parallel Channels of Multiple Cameras for Accurate ANN Reconstruction of Reflectance Spectra.” Tehnički Vjesnik, 29: 765–774. Slavuj, R.; Green, P. 2013. “To develop a method of estimating spectral reflectance from camera RGB values.” Colour and Visual Computing Symposium (CVCS). IEEE, 2013: p. 1-6 Zhao, J., Kechasov, D., Rewald, B., Bodner, G., Verheul, M., Clarke, N., Clarke, J. L. 2020. “Deep learning in hyperspectral image reconstruction from single RGB images—A case study on tomato quality parameters.” Remote Sensing, 12(19): 3258. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Mihael LAZAR, PhD. Aleš HLADNIK, Prof. PhD and Engineering Department of Textiles, Department of Textiles, Graphic Arts and Design Graphic Arts and Design Snežniška ulica 5 Snežniška ulica 5 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia Faculty of Natural Sciences Faculty of Natural Sciences and Engineering University of Ljubljana University of Ljubljana ales.hladnik@ntf.uni-lj.si mihael.lazar@ntf.uni-lj.si 519 SUBSTRATES AND STANDARDIZATION 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION SLOVENIAN INSTITUTE FOR STANDARDIZATION AND WORK OF TECHNICAL COMMITTEES GRAPHIC TECHNOLOGY, PACKAGING - SALES AND GROUPED AND PULP, PAPER, BOARD AND PRODUCTS Mojca Lampič1 1Slovenian Institute for Standardization, Slovenia Abstract: My presentation will focus on working activities of SIST – Slovenian Institu- te for Standardization, Ljubljana, Slovenia – EU, where several various active technical committe-es are established, among many others as well technical committee SIST/TC GRT Graphic technolo-gy, SIST/TC EPO Packaging – sales and grouped and SIST/TC VPK Pulp, paper, board and products. In the presentation I am briefly presenting some basic rules in the field of standardization that are important for the experts working procedures, pointing out the general importance of standards, why they are needed in modern world, where are their main advantages of use in business environment (companies), that is on different levels, and in various (specific) areas. I am also identifying certain most relevant and important principles of standardiza-tion, the process of creating standardization documents, ways of adopting standards (by adoption, with transla-tion) and specifying the types of standardization documents. In conclusion I am referring to the work of SIST/TC GRT, SIST/TC EPO and SIST/TC VPK.. Keywords: SIST, rules, standards, SIST/TC GRT, SIST/TC EPO, SIST/TC VPK. 1. THE SLOVENIAN INSTITUTE FOR STANDARDIZATION (SIST) The Slovenian Institute for Standardization (SIST) is the Slovenian national body responsible for the preparation and issuance of SIST Slovenian standards. It represents Slovenia’s interests in international standards organizations such as ISO and IEC, as well as Euro-pean ones such as CEN, CENELEC, ETSI. Members of the Slovenian technical committees (SIST/TC) have the opportunity to equally participate in all standardization activities, in Slovenia, Europe and the world and can collaborate to create European and inter-national standards. 2. THE BASIC RULES OF THE SIST Standardization principles: - participation by all interested parties is voluntary; - the content of the Slovenian national standards has consensus – agreement in principle of a significant part of interested parties; - preventing the dominance of individual interests over the common interest of interested parties;- Slovenian national standards transparency require work transparency and accessibility for the public;- taking into account the techniques and rules that have been achieved through international and European standardization. 521 29–30 May 2025, Ljubljana, Slovenia Professional technical work is carried out within the framework of SIST in technical working bodies (TDT), i.e.: - technical committees (SIST/TC), - sub-committees (SIST/SC) and - working groups (SIST/WG). The professional technical work in SIST supervises: - members of the technical education board that specializes in electrical engineering and- members of the board of technical experts in the general field. Members of the board technic are responsible for the following tasks: - establish, reform and dissolve TDT to determine the rules for professional work, - decide in case there is a misunderstanding between the SIST technical committees or within the techni- cal committees, - they take care of standards in the field, where there are no active SIST technical committees. Participation in technical working bodies means the possibility of: - expert’s representing the interests of the institution from which she/he comes to participate in the preparation of international, European and original national standards, - expert’s, based on the application, participation in the working groups of international or European orga- nizations for standardization, - expert’s participation in voting decisions on the content of international, European and original national standards, - receiving working material of draft standards (prEN, FprEN),- tracking technical progress, reflected in standards, - knowledge and experience exchange at meetings etc. The basic rules on the establishment and working method of technical working documents are: - quorum at the meeting, - consensus on essential issues, - when approving standardization documents, 75% votes of the members present are required, - resolutions are adopted by the majority of votes of the members present,- meetings with presence/correspondence/hybrid. 522 The basic rules on the establishment and working method of technical working documents are: - quorum at the meeting, - consensus on essential issues, 29–30 May 2025, Ljubljana, Slovenia - when approving standardization documents, 75% votes of the members present are required, - resolutions are adopted by the majority of votes of the members present, - meetings with presence/correspondence/hybrid. ISO IEC SIST CEN CENELEC ETSI ASSEMBLY PRESIDENT COUNCIL DIRECTOR TECHNICAL BOARD TECHNICAL BOARD (General) (electrical engineering, information technology and telecommunications) SECRETARIAT TECHNICAL TECHNICAL WORKING BODIES WORKING BODIES Figure 1: SIST Bodies Figure 1: SIST Bodies 3. THE BENEFITS OF HAVING STANDARDS A standard is a document created by consensus and approved by a recognized authority which defines rules, guidelines or characteristics for activities and their results and is intended for general and repeated use and ai 2 -med at achieving an optimal level of regulation in a given field. 4. ADVANTAGES COMPANIES CAN GAIN FROM USING STANDARDS - better efficiency, fewer costs, and less waste, - ensure the high quality and safety of products, - the compatibility between products or services, - the access to the EU internal market and the reputation of companies; the use of the EN standard in Euro-pean countries has a potential internal market of more than 500 million (potential) consumers 5. ADVANTAGES OF PARTICIPATING IN THE STANDARDIZATION PROCESS - co-creation of national standards in Slovenia, - the possibility of impacting the content of European and international standards,- accessible experts information about the most up-to-date (recent) techniques,- achieving access to draft standards and working materials that are not freely accessible,- establishing and developing business connections in meetings,- harmonized terminology. 523 29–30 May 2025, Ljubljana, Slovenia 6. STANDARDS PREPARATION - in the Slovenian national standardization sistem there are almost 36.000 valid standards, - professional standardization work takes place in technical committees (SIST/TC),- currently 81 SIST/TC are active (47 among them in the general field of standardization),- the preparation time of the standard is approximately 2 years, the revision of the standard is in principle every 5 years, - during the public enquiry there is the possibility of free access to draft standards. 7. TYPES OF STANDARDIZATION DOCUMENTS - International ISO, - European EN, - National SIST (SIST EN, SIST ISO), - Technical specifications TS, - Reports TR, - Guide (Guide - V). 8. STANDARDS ADOPTION METHODS Members of CEN, CENELEC and ETSI must adopt all European standards within 6 months. International standards and other national standards are adopted by initiative. The methods of adoption of standards are the same in all cases; - method of adoption, - translation method, - original Slovenian standard. 9. ALL INTERESTED PARTIES CAN JOIN THE TECHNICAL COMMITTEES All interested parties can join the technical committee with a written application and a signed access declaration. Members of the technical committee have the following rights and benefits: - they participate in the technical committee, - ability to influence the content of Slovenian national, European and international standards,- ability to represent national interests in European and international standardization,- they have access to information that is otherwise not freely available (intellectual property). 10. TECHNICAL COMMITTEE SIST/TC GRT GRAPHIC TECHNOLOGY In the committee there are currently 4 experts involved in a standardization work. At the European level, they monitor the work of: CEN/SS F14 - Graphical Technology, Sign-boards and Nameplates CEN/SS F18 - Micrographics CEN/TC 198 - Printing and paper machinery - Safety CEN/TC 198/WG 1 - Printing and paper converting machines - Drafting of safety standards CEN/TC 198/WG 2 - Paper Machinery CEN/TC 198/WG 3 - Paper making machines - Noise At the international level, they monitor the work of: ISO/TC 130 - Graphic technology ISO/TC 42 – Photography. 524 29–30 May 2025, Ljubljana, Slovenia European technical committees also cooperate with international technical committees and therefore European standards are in the field of graphic technology as well adopted as international standards. SIST/TC GRT adopts European and International standards as Slovenian national standards. Experts also parti-cipate in public enquiry of draft standards and formal voting of European and international final draft standards. By 1 February 2025 in the field of graphic technology, there will have been issued 166 Slovenian standards. For the year 2025, the members of SIST/TC GRT Graphic technology plan to translate following standards: SIST ISO 12637-1:2010 Graphic technology - Vocabulary - Part 1: Fundamental terms SIST ISO 12637-2:2010 Graphic technology - Vocabulary - Part 2: Prepress terms SIST ISO 12637-3:2010 Graphic technology - Vocabulary - Part 3: Printing terms SIST ISO 12637-4:2010 Graphic technology - Vocabulary - Part 4: Postpress terms. 11. TECHNICAL COMMITTEE SIST/TC EPO PACKAGING - SALES AND GROUPED In the committee there are currently 6 experts involved in a standardization work. At the European level, they monitor the work of: CEN/TC 120 - Sacks for the transport of food aid CEN/TC 194 - Utensils in contact with food CEN/TC 253 - Self adhesive tapes CEN/TC 261 - Packaging At the international level, they monitor the work of: ISO/TC 122 - Packaging ISO/TC 51 - Pallets for unit load method of materials handling ISO/TC 52 - Light gauge metal containers ISO/TC 63 - Glass containers ISO/TC 87 – Cork. Experts also participate in public enquiry of draft standards and formal voting of European final draft standards. By 1 February 2025 in the field of packaging - sales and grouped, there will have been issued 353 Slovenian standards. 12. TECHNICAL COMMITTEE SIST/TC VPK PULP, PAPER, BOARD AND PRODUCTS In the committee there are currently 7 experts involved in a standardization work. At the European level, they monitor the work of: CEN/TC 172 - Pulp, paper and board. At the international level, they monitor the work of: ISO/TC 6 - Paper, board and pulps ISO/TC 6/SC 2 - Test methods and quality specifications for paper and board. Experts also participate in public enquiry of draft standards and formal voting of European and international final draft standards. 525 29–30 May 2025, Ljubljana, Slovenia By 1 February 2025 in the field of packaging – sales and grouped, there will have been issued 139 Slovenian standards. For the year 2025, the members of SIST/TC VPK Pulp, paper, board and products plan to translate following standards: SIST ISO 4046-1:2016 Paper, board, pulps and related terms - Vocabulary - Part 1: Alphabetical index SIST ISO 4046-2:2016 Paper, board, pulps and related terms - Vocabulary - Part 2: Pulping terminology SIST ISO 4046-3:2016 Paper, board, pulps and related terms - Vocabulary - Part 3: Paper-making terminology SIST ISO 4046-4:2016 Paper, board, pulps and related terms -- Vocabulary -- Part 4: Paper and board grades and converted products SIST ISO 4046-5:2016 Paper, board, pulps and related terms - Vocabulary - Part 5: Properties of pulp, paper and board. Standard SIST EN 643:2014 Paper and board - European list of standard grades of paper and board for recycling has been translated into Slovenian language. In this field was also issued the original Slovenian technical specification SIST-TS 1190:2017 Paper and board (paperboard, cardboard and corrugated board) – Archive quality.for preparation of the record, document, books, and for protection of document materials on paper. 13. REFERENCES: mag. Marjetka Strle Vidali, 2024. Secretariat Quality Manual, Edition 22. Ljubljana: SIST. SIST, Standardizacija. URL: https://www.sist.si/standardizacija (Retrieved 27 January 2025). SIST, E-Dostopi/E-Katalog. URL: https://members.sist.si// (Retrieved 27 January 2025). SIST, e-Publikacije. URL: https://www.sist.si/e-sporocila.html (Retrieved 27 January 2025). SIST, Navodilo o postopku sprejemanja slovenskih nacionalnih standardov in drugih dokumentov s področja slovenske nacionalne standardizacije, 26.10.2005. ADDITIONAL DATA ABOUT AUTHOR Corresponding author: M.Sc. Mojca Lampič Slovenian institute for Standardization Ulica gledališča BTC 2 1000 Ljubljana, Slovenia mojca.lampic@sist.si +386 1 478 3003 www.sist.si 526 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION STARCH-BASED FILMS REINFORCED WITH BACTERIAL NANOCELLULOSE AS PH INDICATORS IN SMART PACKAGING Sanja Mahović Poljaček1, Tamara Tomašegović1, Igor Karlovits2, Urška Kavčič3 3 and Gregor Lavrič 1 University of Zagreb Faculty of Graphic Arts, Croatia 2 Danfoss Trata doo, Slovenia 2 National Institute of Chemistry, Slovenia 3 Pulp and Paper Institute, Slovenia Abstract: The aim of this research was the production of starch-based films with the addition of anthocyanins from red cabbage and bacterial nanocellulose (BNC). BNC was added in different concentrations in polymer com-posites, as it can be used as an additive that could improve the properties of the produced films. The mechanical, surface and colorimetric properties of the produced films were evaluated. It was expected that a higher BNC concentration would improve the mechanical properties and have little effect on the colorimetric and surface pro-perties of the indicators. The optimal concentrations of starch and BNC, and the colorimetric response of the films were defined. The study has shown that BNC can stabilize the anthocyanins at different pH values and prolong their stability, but may reduce the range of colorimetric changes in the films, which should be taken into account in the preparation of the proposed films. Keywords: Starch-based films, bacterial nanocellulose, pH indicators, smart packaging. 1. INTRODUCTION Bacterial nanocellulose (BNC) is an emerging material with significant potential for bio-based smart packaging applications due to its unique properties and compatibility with sustainable practices (Bhargava, 2020; 2020; Ashfaq, 2022). BNC is fully biodegradable, making it an environmentally friendly alternative to synthetic polymers. Research into the production of starch-based films with the addition of bacterial nanocellulose (BNC) has shown great potential in smart packaging applications. In the production of polymer composite films and by adding a natural pigment, pH indicators can be produced to visually monitor food quality in the packaging container by detecting pH fluctuations in the packaging environment (Brockgreitens, 2016; Vasuki, 2023). Embedded starch/ BNC films with a pH sensing element can provide a visible color change in response to volatile amines or acids produced by microbial activity on the food surface and provide real-time food quality information. They could be used to monitor the freshness of perishable products such as meat, fish and dairy products (Liu, 2022). The pro-duction of starch-based indicators can vary depending on the starch source, pH sensing element and plasticizer used, as well as the desired film properties (Pounds, 2021). Previously published studies have shown that it is possible to produce a pH indicator from potato and maize starch with the addition of BNC and anthocyanins extracted from red cabbage (Mahović Poljaček, 2024a, Mahović Pol-jaček, 2024b). Anthocyanins extracted from red cabbage are known for their vivid color changes in response to different pH values. The aim of these studies was to determine the changes in intermolecular interactions betwe-en the components of the films (starch, anthocyanins and BNC) and their influence on the physical, surface and colorimetric properties, which are important for the use of the produced films as pH indicators in smart packaging. It was determined that further research should be carried out, such as analyzing the mechanical and other proper-ties of the produced films relevant to their use in smart packaging applications. The aim of this research was the production of starch-based films with the addition of pH-sensitive elements, anthocyanins extracted from red cabbage, and BNC, in different concentrations. The mechanical, visual and 527 29–30 May 2025, Ljubljana, Slovenia colorimetric properties of the produced films were evaluated. In addition, the produced films were immersed in different pH buffers to observe and determine the colorimetric response of the polymer composite films at chan-ging pH values. 2. EXPERIMENTAL PART 2.1 Film forming solutions Two sets of polymer composites were produced. The first consisted of potato starch (PS) (extra pure, CAS: 9005-25-8) (Carl Roth, Karlsruhe, Germany) and the other of maize starch (MS) (extra pure, CAS: 9005-25-8). BNC was prepared from the cellulose-rich biofilm formed after acetic acid fermentation of apple juice according to the previously published method (Lavrič, 2020). The prepared BNC was obtained in a suspension containing 0.6 % of the dry matter of the BNC. The dry matter content of the BNC suspension was calculated according to (ISO 638-2:2022) and the BNC suspension was isolated at a concentration of 20 %, 40 %, 60 %, 80 % and 100 % (v/v) for the preparation of the starch-based films. Samples without BNC were also prepared as a reference. The film-forming solutions were prepared by dissolving the starches in distilled water with the addition of glacial acetic acid (CAS: 64-19-7) (1 % v/v) and glycerol (purity 99.5 %, CAS: 56-81-5) in various concentrations. Glycerol was added to the potato and maize solutions at a concentration of 20 % (v/v) and 15 % (v/v), respectively. Acetic acid was added at a concentration of 5 % (v/v) for PS-based films and 3 % (v/v) for MS-based films. - Anthocyanins were extracted from the outer leaf debris of fresh red cabbage (Brassica oleracea L.) avail- able in the local market. The extraction method and the calculation of the total monomeric anthocyanin pigment content of red cabbage were performed according to the previously published procedure (Mahović Poljaček, 2024a). The concentration of anthocyanins added to the film-forming solutions was 12% (v/v) for the PS film solution and 14% (v/v) for the MS film solution, based on the previously performed experiments and their color response in different pH buffers (Mahović Poljaček, 2024b). - The production of each starch-based film took about 30 minutes with constant stirring at elevated tem- perature; the film-forming potato starch solution was heated to 60 °C and the maize starch solution to 80 °C to achieve a complete gelatinization process. The film-forming solutions were then poured into Petri dishes, dried and stored in a ventilated climate chamber at 25 °C and 50 % relative humidity (RH) for seven days. The starch-based films produced and their designation are summarized in Table 1. Table 1: Starch-based films produced in the research Starch type BNC (%) Designation Starch type BNC (%) Designation 0 PS_0BNC 0 MS_0BNC 20 PS_20BNC 20 MS_20BNC 40 PS_40BNC 40 MS_40BNC Potato (PS) Maize (MS) 60 PS_60BNC 60 MS_60BNC 80 PS_80BNC 80 MS_80BNC 100 PS_100BNC 100 MS_100BNC 2.2 Methods The mechanical properties were measured using the Zwick Roell Z010 tensile testing machine with 20 N measu-ring cell (class 0.5, ISO 7500-1) and the testXpert testing software (version II V3.2, Zwick GmbH & Co. KG). The tensile properties of the films were determined in accordance with modified ASTM D 882 and expressed as tensile strength (TS, in MPa), Young’s modulus of elasticity (YM, in MPa) and elongation at break in percent (ε, %). The size of the sample was set to a width of 20 mm and tested at a test speed of 25 mm/min; the clamping length was set at 40 mm. The test was carried out at 23 °C and 50 % RH. The colorimetric properties of the prepared films were measured before and after immersion in different pH buffer solutions using the Techkon SpectroDens spec-trodensitometer (TECHKON GmbH) (illuminant D50/2°, M1 filter). The CIE L*a*b* values were calculated and the 528 29–30 May 2025, Ljubljana, Slovenia relative CIE L*a*b* values (with paper as white point) were displayed. The results shown are the average values of ten measurements. Photographs were taken of films immersed in different buffer solutions with different pH values to observe the visual change in the films produced. 3. RESULTS AND DISCUSSION 3.1 Mechanical properties The mechanical properties provide an important indication of the influence of the addition of BNC in the film-for-ming solutions on the properties of dried starch-based films. These results are important for predicting the beha-vior of indicators on the surface of packaging materials. The results of the mechanical properties are shown in Table 2. The results of the modulus of elasticity, tensile strength, elongation at break and thickness are shown. The results show that the tensile strength of the potato-based films decreases with the addition of 40 % BNC and increases slightly with further additions of BNC (60, 80 and 100 %). These values indicate that 40% BNC reduces the ultimate strength of the samples and the higher amount of BNC increases it. This trend is consistent with the studies of Tavares de Almeida et al. (Tavares de Almeida, 2024), in which the mechanical strength of potato starch films showed considerable variation with the addition of BNC in the film-forming solution. Nevertheless, it was found that the addition of BNC mainly increased TS and YM, while EAB was reduced. Similar results are shown in the publication by Jeevahan et al. (Jeevahan, 2019), which indicate a strong interaction of BNC with the starch matrix. The results of mechanical measurements performed on maize-based films showed a similar trend in YM and TS results with differences in EAB percentage. A BNC content of 40 % in the film forming solution leads to lower elongation of the samples, and a higher BNC content (60 and 80 %) leads to higher elongation of the sam-ples as the stress required for deformation is higher compared to potato-based films. Table 2: Properties of starch-based films with BNC variation Film sample Young’s Modu- Tensile Stren- Elongation at Thickness (μm) lus (MPa) ght (MPa) Break (%) PS_0BNC 0.085±0.004 0.4445±0.056 34.197±1.793 953 PS_40BNC 0.086±0.002 0.375±0.025 27.276±2.283 1189 PS_60BNC 0.164±0.032 0.499±0.005 15.450±1.233 1139 PS_80BNC 0.164±0.004 0.479±0.009 15.69±0.321 1447 PS_100BNC 0.176±0.009 0.522±0.038 14.683±3.123 1347 MS_0BNC 0.059±0.003 0.613±0.015 50.504±1.044 761 MS_40BNC 0.108±0.004 0.663±0.009 39.538±0.442 767 MS_60BNC 0.129±0.015 0.757±0.006 54.069±1.178 553 MS_80BNC 0.176±0.011 0.895±0.013 53.611±0.569 629 MS_100BNC 0.153±0.013 0.702±0.001 48.563±2.089 576 Figure 1 shows the standard force-elongation curve; Figure 1.a shows the influence of BNC concentration on the properties of potato-based films and Figure 1.b on the properties of maize-based films. According to the measu-rement results, the maize-based films showed higher potential elongation than the potato-based films, indicating greater flexibility, probably due to the better interaction of BNC with maize starch compared to potato starch. It can be said that maize-based films may have greater potential for the production of pH indicators due to the higher elasticity and ultimate strength of the films produced. 529 29–30 May 2025, Ljubljana, Slovenia 80 80 70 70 60 60 ) ) Pa 50 50 (k Pa (k e rc e 40 fo 40 rc d MS_BNC0 fo ar d 30 PS_BNC0 nd 30 MS_BNC40 ar PS_BNC40 nd Sta MS_BNC60 20 20 Sta PS_BNC60 MS_BNC80 PS_BNC80 10 10 MS_BNC100 PS_BNC100 0 0 0 10 20 30 40 50 0 10 20 30 40 50 a) Strian (%) b) Strian (%) Figure 1: Standard force – strain curve for a) potato-based fims and b) maize-based fims 3.2 Colorimetric measurements Figures 2.a -2.b present the lightness (L*) values of the PS-based and MS-based films with different BNC con-tents. The films containing BNC generally exhibited a decrease in L* values across the entire tested pH range compared to the films without BNC. This reduction was notably more significant in the PS-based films (Figure 2.a) and generally for the samples with higher BNC content in buffer solutions with alkaline pH. The observed decre-ase in lightness of the samples with a higher concentration of BNC can be attributed to the optical properties of the BNC (i.e., decreased optical transparency of the samples with higher BNC portion (Almeida, 2023), and to the pronounced swelling of the films in buffers of pH above 9. a) b) Figure 2: Lightness (L*) at different pH values (2.0–10.59): a) PS-based films, b) MS-based films 530 29–30 May 2025, Ljubljana, Slovenia a) b) Figure 2: Lightness (L*) at different pH values (2.0–10.59): a) PS-based films, b) MS-based films trends of the CIE a*/b* shifts in different pH environments, a fourth-degree polynomial trendline has been added Figures 3-4 present the changes in CIE a* and b* values of the produced films. To emphasize and Figures 3-4 present the changes in CIE a* and b* values of the produced films. To emphasize and compare the to the plots. The point labelled „DF“ represents the dry film not immersed in the buffer solutions. compare the trends of the CIE a*/b* shifts in different pH environments, a fourth-degree polynomial trendline has been added to the plots. The point labelled "DF" represents the dry film not immersed in the buffer solutions. a) b) c) d) Figure 3: CIE a*/b* diagrams for PS-based films at different pH values: a) 0% BNC, b) 40% BNC, c) 60% BNC, d) 100% BNC Figure 3: CIE a*/b* diagrams for PS-based films at different pH values: The changes in the pH a) 0% BNC, b) 40% BNC, c) 60% BNC, d) 100% BNC-dependent range of a* and b* values of both PS-based and MS-based films were predominantly influenced by the concentration of BNC in the films, regardless of the starch type. The trendlines of data points in the CIE a*/b* plots (Figure 3-4) showed a noticeable shift towards +b* minantly influenced by the concentration of BNC in the films, regardless of the starch type. of starch and can be attributed to the hue of used BNC. Color shifts occurring in the films as a consequence of the The changes in the pH-dependent range of a* and b* values of both PS-based and MS-based films were predo values with increased concentration of BNC in the films. This occurrence is not dependent on the type -changed pH of the environment start from pink hues at acidic pH, across the mildly The trendlines of data points in the CIE a*/b* plots (Figure 3-4) showed a noticeable shift towards +b* values with yellow hues at neutral pH, towards blue-green hues at alkaline pH. The results of the color shifts are increased concentration of BNC in the films. This occurrence is not dependent on the type of starch and can be alig ned with the previous research. However, the addition of BNC in concentrations higher than 40% attributed to the hue of used BNC. Color shifts occurring in the films as a consequence of the changed pH of the significantly decreased the span of the +a*/-a* color shift. Specifically, the span of measured CIE a* environment start from pink hues at acidic pH, across the mildly yellow hues at neutral pH, towards blue-green values for the sample PS_0BNC was 47.60, and it decreased to 13.59 for PS_100BNC. The span of hues at alkaline pH. The results of the color shifts are aligned with the previous research. However, the addition of BNC in concentrations higher than 40% significantly decreased the span of the +a*/-a* color shift. Specifically, the span of measured CIE a* values for the sample PS_0BNC was 47.60, and it decreased to 13.59 for PS_100BNC. 4 The span of measured CIE a* values for the sample MS_0BNC was 52.07, and was decreased to 8.79 for the sample MS_100BNC. Therefore, the addition of BNC in high concentrations has impaired the colorimetric respon-se and color vividness of the produced films. 531 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia measured CIE a* values for the sample MS_0BNC was 52.07, and was decreased to 8.79 for the sample MS_100BNC. Therefore, the addition of BNC in high concentrations has impaired the colorimetric response and color vividness of the produced films. a) b) c) d) Figure 4: CIE a*/b* diagrams for MS-based films at different pH values: a) 0% BNC, b) 40% BNC, c) 60% BNC, d) 100% BNC The results obtained from this research indicate that BNC can stabilize anthocyanins during exposure to varied The results obtained from this research indicate that BNC can stabilize anthocyanins during exposure Figure 4: CIE a*/b* diagrams for MS-based films at different pH values: a) 0% BNC, b) 40% BNC, c) 60% BNC, d) 100% BNC to varied pH, which is aligned with the previous research (Mahović Poljaček, 2024 a ). BNC can form a network that protects anthocyanins from degradative factors, thereby extending their stability and lifespan. However, because of the interaction of BNC and anthocyanins; and due to the optical and pH, which is aligned with the previous research (Mahović Poljaček, 2024a). BNC can form a network that pro-colorimetric properties of BNC, the range of colorimetric changes occurring in the films when exposed tects anthocyanins from degradative factors, thereby extending their stability and lifespan. However, because of to an enviro nment with varied pH could be significantly reduced. Therefore, the concentration of BNC in the interaction of BNC and anthocyanins; and due to the optical and colorimetric properties of BNC, the range of starch-based films with anthocyanins should be carefully adjusted to maximize both the functional colorimetric changes occurring in the films when exposed to an environment with varied pH could be significantly properties of the produced films and their colorimetric response. reduced. Therefore, the concentration of BNC in starch-based films with anthocyanins should be carefully adjus- ted to maximize both the functional properties of the produced films and their colorimetric response. 4. CONCLUSION This research aimed to produce starch-based films incorporating pH-sensitive anthocyanins from red cabbage and varying concentrations of BNC. Mechanical, visual, and colorimetric properties were This research aimed to produce starch-based films incorporating pH-sensitive anthocyanins from red cabbage BNC initially reduced the tensile strength of PS-based films, while higher concentrations (60-100%) slightly increased it. Similar trends were observed in MS-based films, with higher BNC (60-80%) content and varying concentrations of BNC. Mechanical, visual, and colorimetric properties were evaluated, along with 4. CONCLUSION evaluated, along with the films' responses to different pH buffers. Results indicated that adding 40% the films‘ responses to different pH buffers. Results indicated that adding 40% BNC initially reduced the tensile leading to increased elongation, suggesting greater flexibility. MS-based films demonstrated better flexibility than PS-based films, likely due to improved BNC-starch interactions. The study found that BNC strength of PS-based films, while higher concentrations (60-100%) slightly increased it. Similar trends were ob-could stabilize anthocyanins in varying pH conditions, extending their stability, but might reduce the served in MS-based films, with higher BNC (60-80%) content leading to increased elongation, suggesting greater range of colorimetric changes in the films. Therefore, BNC concentration in films should be optimized flexibility. MS-based films demonstrated better flexibility than PS-based films, likely due to improved BNC-starch for the desired functional properties and maximized colorimetric response. interactions. The study found that BNC could stabilize anthocyanins in varying pH conditions, extending their sta- bility, but might reduce the range of colorimetric changes in the films. Therefore, BNC concentration in films should 5. 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ADDITIONAL DATA ABOUT AUTHOR Corresponding author: Co-author(s): Faculty of Graphic Arts Bogišićeva ulica 8 Getaldićeva 2 1000 Ljubljana, Slovenia Getaldićeva 2 10000, Zagreb, Croatia urska.kavcic@icp-lj.si 10000, Zagreb, Croatia +385 1 2371 080/248 University of Zagreb University of Zagreb Pulp and Paper Institute Faculty of Graphic Arts Sanja Mahović Poljaček Tamara Tomašegović Urška Kavčič tamara.tomasegovic@grf.unizg.hr Gregor lavrič +385 1 2371 080/129 Pulp and Paper Institute sanja.mahovic.poljacek@grf.unizg.hr Igor Karlovits Bogišićeva ulica 8 Danfoss Trata d.o.o. 1000 Ljubljana, Slovenia Jožeta Jame 16 gregor.lavric@icp-lj.si 1210 Šentvid, Slovenia National Institute of Chemistry 1000 Ljubljana, Slovenia igor.karlovits@danfoss.com 533 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION SCREEN-PRINTED IRREVERSIBLE THERMOCHROMIC INDICATORS UTILISING SINGLE AND MIXED LEUCO DYE SYSTEMS Eva Pogorelc1,2, Marta Klanjšek Gunde2,3, Ondrej Panák2,3 1 and Raša Urbas 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2Mysteria Colorum – MyCol d.o.o., Slovenia 3National Institute of Chemistry, Slovenia Abstract: Effective temperature control is essential in various industrial applications to prevent equipment from overheating and to ensure product quality. A cost-effective solution is the use of screen-printed irreversible tempe-rature indicators with thermochromic systems based on leuco dyes. In this study, the effectiveness of temperature indicators with mixtures of two leuco dye systems with different colour transition temperatures was investigated. Five different indicators with blue and green leuco dyes and their mixtures were produced. For all samples, the co-lour parameters (L*, a*, b*, chroma and hue angle) were measured as a function of temperature and their thermal behaviour evaluated. Single-dye indicators showed sharp colour transitions within narrow temperature ranges, while mixed-dye indicators showed gradual colour transitions. Keywords: Thermochromism, thermochromic inks, leuco dyes, screen printing, colourimetry. 1. INTRODUCTION Temperature control plays a critical role in numerous industrial applications, especially in scenarios where overhe-ating poses a significant risk to equipment performance and longevity (Almubarak, 2017). Effective monitoring and management of temperature is essential to prevent equipment failure and ensure the safety and efficiency of industrial processes. On the other hand, in some production processes, certain heating thresholds must be met for each product (Panayiotou, 2017; Tadini, 2022). In both cases, conventional temperature sensors based on electrical components are often unsuitable. This limitation is particularly evident when temperature measure-ments are required on surfaces that are difficult to access or in dynamic production lines. In such cases, there is a growing need for cost-effective and user-friendly temperature sensing solutions to ensure consistent quality and process reliability. One possible solution to this problem is the use of printed indicators for critical temperatures that contain ther-mochromic systems based on leuco dyes (Jenko, 2021; Pogorelc, 2023). They are screen-printed with ther-mochromic ink on self-adhesive labelling materials so that they can be easily applied to the object in question. These indicators undergo a colour transition from white to a strongly coloured state, with the final colour being determined by the type of leuco dye used once a certain critical temperature is reached (Seeboth, 2013; White, 1999). In one case, the colouration returns to white on cooling, making this type of indicator reversible. In the other case, the colouration remains even after cooling, providing the user with a visual record of the object’s thermal history. 534 29–30 May 2025, Ljubljana, Slovenia Earlier studies mostly focussed on reversible thermochromic printing inks. Kulčar et al. investigated the coloura-tion behaviour as a function of temperature of binary mixtures of commercially available thermochromic printing inks (Kulčar, 2011). Two mixtures were analysed: one containing ink with similar colour transition temperatures and another with different transition temperatures. In the first case, a single-colour transition was observed at a temperature between the transition points of the individual thermochromic inks. In contrast, two separate and dis-tinct colour transitions were observed in the mixture with different transition temperatures. Reversible thermochro-mic inks are usually microencapsulated to prevent unwanted contamination and ensure a reversible colour chan-ge. Irreversible thermochromic systems are designed for single use applications, i.e. for only one colour change, which requires a different formulation and composition. This raises an interesting question: How do irreversible thermochromic indicators behave when prepared with a mixture of two thermochromic inks, each with different transition temperatures? To investigate this, five different thermochromic indicators were prepared. Two of these were prepared for different transition temperatures and contained a single dye, while the remaining three were prepared by mixing the two dyes in different ratios. These indicators were then heated to specific temperatures, and several colour parameters were measured in the CIELAB colour space as a function of temperature (Kulčar, 2010; Panák, 2015). The results provided insights into the thermal behaviour of both single-dye and mixed-dye systems over a wider temperature range. 2. EXPERIMENTAL Five different water-based thermochromic screen-printing inks were prepared. The mass fraction (%) of all com-ponents was kept constant for all inks produced, with the exception of the different content of the two dyes, blue and green. The five inks were prepared with different ratios of these two dyes, so that their cumulative weight in the ink was the same ratio. The ratio of the two dyes forming the dye component of the five inks is shown in Table 1. The critical temperature indicators were screen-printed using thermochromic ink with a screen-printing mesh of 61 𝜇m diameter and a density of 64 threads/cm on self-adhesive polyester foil JAC SERIPOL Silver Matt (Avery Dennison, USA). Table 1: Ratio of dyes in the dye component of the prepared inks (using mass fraction). Ratio of dyes in dye component Indicator Blue dye (%) Green dye (%) 100B–0G 100 0 75B–25G 75 25 50B–50G 50 50 25B–75G 25 75 0B–100G 0 100 The indicators were heated in a laboratory oven SP-55 EASY (Kambič, Slovenia) for 15 minutes at temperatures from 130 to 180 °C in steps of 5 °C and cooled to room temperature. The colouration was irreversible, i.e. no co-lour change was observed on cooling. A new label indicator was used for each temperature in the oven. Several colour parameters of the indicators, including L*, a* and b*, chroma and hue angle, were determined from reflectance measurements with the Datacolor Spectro 1050 spectrophotometer (Datacolor, Switzerland). The geometry used was di:8°, the radius of the integrating sphere was 152 mm and the radius of the sample aperture was 3 mm. The light source was a xenon lamp. Specular reflection was excluded. The spectra were measured between 400 and 700 nm with a step of 10 nm and processed using software from Datacolor applications. The 2° standard observer and illuminant D50 were used to calculate the colour parameters. Each sample was measu-red three times so that their average values were used. The colour differences between unheated samples and samples heated to a certain temperature were calculated using the simple colour difference ΔΕ* according to ab 535 determined from reflectance measurements with the Datacolor Spectro 1050 spectrophotometer (Datacolor, Switzerland). The geometry used was di:8°, the radius of the integrating sphere was 152 mm and the radius of the sample aperture was 3 mm. The light source was a xenon lamp. Specular reflection 29–30 May 2025, Ljubljana, Slovenia was excluded. The spectra were measured between 400 and 700 nm with a step of 10 nm and processed using software from Datacolor applications. The 2° standard observer and illuminant D50 were used to calculate the colour parameters. Each sample was measured three times so that their average values were used. The colour differences between unheated samples and samples heated to Equation 1, where L* , a* and b* are the values of the unheated indicators and the values L*, a* and b* when where a certain temperature were calculated using the simple colour difference ΔΕ*ab according to Equation 1, heated to a certain temperature (Hunt, 2011). heated to a certain temperature (Hunt, 2011). L*0, a*0 and 0b*0 are the values of the unheated indicators and the values 0 0L*, a* and b* when 𝛥𝛥𝛥𝛥𝛥𝛥𝛥𝛥 ∗ ∗ ∗ ∗ ∗ (1) 𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎 = � ( 𝐿𝐿𝐿𝐿 ) 0 − 𝐿𝐿𝐿𝐿 ∗ ) 2 + ( 𝑎𝑎𝑎𝑎 ∗ ) 2 0 − 𝑎𝑎𝑎𝑎 + ( 𝑏𝑏𝑏𝑏 0 −𝑏𝑏𝑏𝑏 2 To better assess the results, we calculated the cumulative colour difference at a given temperature, ΔΕ (T), using ΔΕ To better assess the results, we calculated the cumulative colour difference at a given temperature, i=2 i=2 indicator heated to 135 °C and so on) were used to calculate the colour 29–30 May 2025, Ljubljana, Slovenia indicator heated to 135 °C and so on) were used to calculate the colour difference between samples heated to difference between samples heated to two adjacent temperatures. Equation 2 (Panák, 2015). The L*, a* and b* values of a sample i (where 29–30 May 2025, Ljubljana, Slovenia i=1 marks indicator heated to 130 °C, indicator heated to 130 °C, C C ( T ), using Equation 2 (Panák, 2015). The L *, a * and b * values of a sample i (where i=1 marks ΔΕC(T) is then determined as the two adjacent temperatures. ΔΕ (T) is then determined as the sum of these differences until the sample is heated sum of these differences until the sample is heated to the desired temperature C m ( T ). to the desired temperature m(T). 𝛥𝛥𝛥𝛥𝛥𝛥𝛥𝛥 𝑚𝑚𝑚𝑚(𝑇𝑇𝑇𝑇) (2) 𝑚𝑚𝑚𝑚 ( 𝑇𝑇𝑇𝑇 ) (2) ∗ ∗ ∗ 2 C ( 𝑇𝑇𝑇𝑇 ) = � � ( 𝐿𝐿𝐿𝐿 − 𝐿𝐿𝐿𝐿 ) 2 ∗ ∗ ∗ + ( 𝑎𝑎𝑎𝑎 − 𝑎𝑎𝑎𝑎 ) 2 + ( 𝑏𝑏𝑏𝑏 −𝑏𝑏𝑏𝑏 ) 2 ∗ 𝑖𝑖𝑖𝑖 ∗ 𝑖𝑖𝑖𝑖𝑖𝑖 ∗ ∗ 𝛥𝛥𝛥𝛥𝛥𝛥𝛥𝛥 C ( 𝑇𝑇𝑇𝑇 ) = � � ( 𝐿𝐿𝐿𝐿 ) 2 𝑖𝑖𝑖𝑖 − 𝐿𝐿𝐿𝐿 2 ∗ 𝑖𝑖𝑖𝑖 𝑖𝑖𝑖𝑖𝑖𝑖 ∗ 𝑖𝑖𝑖𝑖 𝑖𝑖𝑖𝑖𝑖𝑖 ) 2 𝑖𝑖𝑖𝑖𝑖𝑖 + ( 𝑎𝑎𝑎𝑎 ) 𝑖𝑖𝑖𝑖 − 𝑎𝑎𝑎𝑎 𝑖𝑖𝑖𝑖𝑖𝑖 + ( 𝑏𝑏𝑏𝑏 𝑖𝑖𝑖𝑖 −𝑏𝑏𝑏𝑏 𝑖𝑖𝑖𝑖𝑖𝑖 𝑖𝑖𝑖𝑖>𝑖 𝑖𝑖𝑖𝑖>𝑖 3. 3. RESULTS WITH DISCUSSION 3. RESULTS WITH DISCUSSION RESULTS WITH DISCUSSION 3.1 3.1 Colour coordinates in CIELAB colour space Colour coordinates in CIELAB colour space 3.1 Colour coordinates in CIELAB colour space Multiple colour parameters were measured for all indicators. As illustrated in Figure 1, the L* parameter Multiple colour parameters were measured for all indicators. As illustrated in Figure 1, the Multiple colour parameters were measured for all indicators. As illustrated in Figure 1, the L * parameter decreases L * parameter decreases significantly with increasing temperature, indicating a transition from white at temperatures significantly with increasing temperature, indicating a transition from white at temperatures below the critical value decreases significantly with increasing temperature, indicating a transition from white at temperatures below the critical value to dark colours at temperatures well above. Both single-dye indicators undergo to dark colours at temperatures well above. Both single-dye indicators undergo this change within a narrow range below the critical value to dark colours at temperatures well above. Both single-dye indicators undergo this change within a narrow range of about 10 °C. For example, the blue-dye indicator (100B–0G) begins of about 10 °C. For example, the blue-dye indicator (100B–0G) begins to show a decrease in this change within a narrow range of about 10 °C. For example, the blue-dye indicator (100B–0G) begins L * at 145 °C, while to show a decrease in L * at 145 °C, while the green-dye indicator (0B–100G) does so at 160 °C. In the green-dye indicator (0B–100G) does so at 160 °C. In contrast, mixed-dye systems show a more gradual and to show a decrease in L * at 145 °C, while the green-dye indicator (0B–100G) does so at 160 °C. In contrast, mixed-dye systems show a more gradual and continuous decrease in L * over a wider continuous decrease in contrast, mixed-dye systems show a more gradual and continuous decrease in L * over a wider temperature range, suggesting that the mixed dyes influence the thermal L * over a wider temperature range, suggesting that the mixed dyes influence the thermal response. Once the response. Once the temperature reaches 165 °C or more, the temperature range, suggesting that the mixed dyes influence the thermal response. Once the L * values of all samples converge to approximately temperature reaches 165 °C or more, the L * values of all samples converge to approximately 29 ± 3, 29 ± 3, indicating that they take on a dark almost achromatic appearance regardless of dye type or ratio. temperature reaches 165 °C or more, the L * values of all samples converge to approximately 29 ± 3, indicating that they take on a dark almost achromatic appearance regardless of dye type or ratio. indicating that they take on a dark almost achromatic appearance regardless of dye type or ratio. Figure 1: L* as a function of temperature (left) and Figure 1: L* as a function of temperature (left) and a*, b* values (right). a* , b * values (right). Figure 1: L * as a function of temperature (left) and a* , b * values (right). negative both b * decreases to -34, and a* changes from negative to positive a * and b * values at 130 °C, which corresponds to a blue hue. Above 150 °C, b * decreases to -34, corresponds to a blue hue. Above 150 °C, b * decreases to -34, and a * changes from negative to positive values. This change indicates the development of a strong blue colour, which becomes darker with and a * changes from negative to positive values. This change indicates the development of a strong blue colour, values. This change indicates the development of a strong blue colour, which becomes darker with further heating. For mixed-dye indicators, the a b values are more strongly grouped together at 130 °C, which becomes darker with further heating. For mixed-dye indicators, the a further heating. For mixed-dye indicators, the a b values are more strongly grouped b values are more strongly grouped together at 130 °C, with both a * and b * values being negative. At this temperature, the b* values are relatively consistent, together at 130 °C, with both with both a * and b * values being negative. At this temperature, the a * and b * values being negative. At this temperature, the b* values are relatively consistent, b* values are relatively while the a* values show minor deviations that are not strongly correlated with the dye ratios. With further consistent, while the while the a* values show minor deviations that are not strongly correlated with the dye ratios. With further a* values show minor deviations that are not strongly correlated with the dye ratios. With heating, the a * minima shift to lower temperatures and show more gradual transitions compared to further heating, the heating, the a * minima shift to lower temperatures and show more gradual transitions compared to a * minima shift to lower temperatures and show more gradual transitions compared to single-single-dye indicators. Similarly, the b * transitions are more gradual for mixed-dye indicators, but the b * single-dye indicators. Similarly, the b * transitions are more gradual for mixed-dye indicators, but the b * is more strongly influenced by the dye ratios. Indicators with a higher blue-dye content (75B–25G) is more strongly influenced by the dye ratios. Indicators with a higher blue-dye content (75B–25G) maintain negative b* values over the entire temperature range. In comparison, indicators with a higher maintain negative b* values over the entire temperature range. In comparison, indicators with a higher green-dye content (25B–75G) show a transition to positive (0B–100G), heating to 130 °C results in a negative a* decreases sharply at 160 °C, corresponding to the onset a * value and a positive b * value, indicating a slightly green hue. a slightly green hue. With further heating, a* decreases sharply at 160 °C, corresponding to the onset of a strong green colouration, and then gradually decreases to zero as the indicator darkens. In With further heating, a* decreases sharply at 160 °C, corresponding to the onset of a strong green colouration, and of a strong green colouration, and then gradually decreases to zero as the indicator darkens. In comparison, the blue-dye indicator (100B–0G) has negative both a * and b * values at 130 °C, which then gradually decreases to zero as the indicator darkens. In comparison, the blue-dye indicator (100B–0G) has comparison, the blue-dye indicator (100B–0G) has negative both a * and b * values at 130 °C, which corresponds to a blue hue. Above 150 °C, The a* value and a positive b* value, indicating a * and b * values for all samples are shown in the a * b * diagram in Figure 1. For the green-dye indicator indicator (0B–100G), heating to 130 °C results in a negative a * value and a positive b * value, indicating a slightly green hue. With further heating, The a* and b* values for all samples are shown in the a*b* diagram in Figure 1. For the green-dye indicator (0B–100G), heating to 130 °C results in a negative The a* and b* values for all samples are shown in the a*b* diagram in Figure 1. For the green-dye green-dye content (25B–75G) show a transition to positive b* values above 140 °C. An equal mixture 536 b * values above 140 °C. An equal mixture (50B–50G) shows b* values close to zero above 140 °C, reflecting an earlier onset of blue colouration compared to green one with the increasing temperature. (50B–50G) shows b* values close to zero above 140 °C, reflecting an earlier onset of blue colouration compared to green one with the increasing temperature. 29–30 May 2025, Ljubljana, Slovenia dye indicators. Similarly, the b* transitions are more gradual for mixed-dye indicators, but the b* is more strongly influenced by the dye ratios. Indicators with a higher blue-dye content (75B–25G) maintain negative b* values over the entire temperature range. In comparison, indicators with a higher green-dye content (25B–75G) show a transition to positive b* values above 140 °C. An equal mixture (50B–50G) shows b* values close to zero above 140 °C, reflecting an earlier onset of blue colouration compared to green one with the increasing temperature. 29–30 May 2025, Ljubljana, Slovenia At the same time as the parameters L*, a* and b*, the colour purity (chroma) and the hue angle were collected for all five indicators as a function of temperature (Figure 2). Figure 2: Chroma (left) and hue angle (right) as a function of temperature. Figure 2: Chroma (left) and hue angle (right) as a function of temperature. The most pronounced increase in chroma can be observed in sample 100B–0G around 150 °C, which can be attri The most pronounced increase in chroma can be observed in sample 100B–0G around 150 °C, which -buted to the strong blue colouration. A similar, although weaker effect occurs with 0B–100G around 160 °C, reflec can be attributed to the strong blue colouration. A similar, although weaker effect occurs with 0B–100G - values overall, suggesting that the chroma of the blue dye has been displaced by the less chromatic green dye. 75B– 25G) show more moderate chroma values overall, suggesting that the chroma of the blue dye has been displaced by the less chromatic green dye. ting its green hue. Indicators containing both dyes (25B–75G, 50B–50G, 75B– around 160 °C, reflecting its green hue. Indicators containing both dyes (25B–75G, 50B–50G, 25G) show more moderate chroma transition. The indicators 25B–75G and 50B–50G initially show a slight drop in the hue angle before it increases remains relatively stable up to a temperature of about 160 °C, where a slight increase can be observed due to the green transition. The indicators 25B–75G and 50B–50G initially show a slight drop in the hue rapidly at higher temperatures (approx. 175 and 170 °C respectively). For sample 75B–25G, the hue angle incre-angle before it increases rapidly at higher temperatures (approx. 175 and 170 °C respectively). For ases steadily up to around 165 °C and then shows a sharper increase. Sample 100B–0G shows higher hue angle latively stable up to a temperature of about 160 °C, where a slight increase can be observed due to the green The hue angle largely follows the colour distribution on the colour wheel. For sample 0B–100G, it The hue angle largely follows the colour distribution on the colour wheel. For sample 0B–100G, it remains re- values at all temperatures, with significant shifts at 140 °C (its main hue transition) and again above 160 °C when increase. Sample 100B–0G shows higher hue angle values at all temperatures, with significant shifts at sample 75B–25G, the hue angle increases steadily up to around 165 °C and then shows a sharper it transitions to dark, almost achromatic colour. 140 °C (its main hue transition) and again above 160 °C when it transitions to dark, almost achromatic colour. 3.2 Colour difference An important parameter in the evaluation of temperature indicators is the colour difference as a function of temperature. Figure 3 shows the colour change compared to the initial, room-temperature colour (calculated with Equation 1) and the cumulative colour change (calculated with Equation 2). Figure 3: Colour difference between unheated and heated samples (left) and cumulative colour difference (right) as a function of temperature. Single-dye indicators 0B–100G and 100B–0G show sharp colour transitions in the ranges 155–165 °C 537 and 140–150 °C respectively, after which their colour remains relatively stable. Mixed-dye indicators (25B–75G, 50B–50G, 75B–25G) change colour at around 135 °C and continue their gradual – almost linear – change over a wider range. These results indicate that dye mixtures flatten and lengthen the The hue angle largely follows the colour distribution on the colour wheel. For sample 0B–100G, it remains relatively stable up to a temperature of about 160 °C, where a slight increase can be observed due to the green transition. The indicators 25B–75G and 50B–50G initially show a slight drop in the hue angle before it increases rapidly at higher temperatures (approx. 175 and 170 °C respectively). For 29–30 May 2025, Ljubljana, Slovenia sample 75B–25G, the hue angle increases steadily up to around 165 °C and then shows a sharper increase. Sample 100B–0G shows higher hue angle values at all temperatures, with significant shifts at 140 °C (its main hue transition) and again above 160 °C when it transitions to dark, almost achromatic colour. 3.2 Colour difference An important parameter in the evaluation of temperature indicators is the colour difference as a function of tem-An important parameter in the evaluation of temperature indicators is the colour difference as a function 3.2 Colour difference perature. Figure 3 shows the colour change compared to the initial, room-temperature colour (calculated with of temperature. Figure 3 shows the colour change compared to the initial, room-temperature colour Equation 1) and the cumulative colour change (calculated with Equation 2). (calculated with Equation 1) and the cumulative colour change (calculated with Equation 2). Figure 3: Colour difference between unheated and heated samples (left) and cumulative colour difference (right) as a function Figure 3: Colour difference between unheated and heated samples (left) and cumulative colour of temperature. difference (right) as a function of temperature. 150 °C respectively, after which their colour remains relatively stable. Mixed-dye indicators (25B–75G, 50B–50G, and 140–150 °C respectively, after which their colour remains relatively stable. Mixed-dye indicators (25B–75G, 50B–50G, 75B–25G) change colour at around 135 °C and continue their gradual – almost Single-dye indicators 0B–100G and 100B–0G show sharp colour transitions in the ranges 155–165 °C and 140– Single-dye indicators 0B–100G and 100B–0G show sharp colour transitions in the ranges 155–165 °C range. These results indicate that dye mixtures flatten and lengthen the colouration interval, while the dye ratio linear – change over a wider range. These results indicate that dye mixtures flatten and lengthen the 75B–25G) change colour at around 135 °C and continue their gradual – almost linear – change over a wider mainly influences the final perceived colour. The colour difference between unheated and to 180 °C heated sam colouration interval, while the dye ratio mainly influences the final perceived colour. The colour difference -ples is relatively similar for all indicators and varies by only about 5 units. For the single-dye indicators, the colour differences are 61 for 0B–100G and 66 for 100B⁠⁠‒⁠0G. In comparison, the colour differences for the mixed-dye indicators 25B–75G, 50B–50G, and 75B‒25G are 61, 63 and 64 respectively. 4 The cumulative colour difference of the green single-dye indicator (0B–100G) shows only a slight difference in colour change compared to the initial, room-temperature colour. At 180 °C it reaches similar values at 64. In com-parison, the blue single-dye indicator (100B–0G) shows the same strong colour transition when heated above 140 °C, and the cumulative colour difference then increases above 150 °C. This shows that the colour changes continuously from blue to dark, almost black, even when heated further. Mixed-dye samples show a continuous increase in cumulative colour difference as a function of temperature in a range of interest. 4. CONCLUSIONS This study investigated the effect of combining leuco dyes to critical temperature indicators. Five different critical temperature indicators were prepared by screen-printing thermochromic inks on self-adhesive polyester foil. Their colour parameters were investigated in dependence of temperature. Two single-dye indicators, one containing a blue dye and the other a green dye, showed sharp colour changes within narrow temperature intervals between 140–150 and 155–165 °C, respectively. On the other hand, indicators with mixed dyes (ratios of green at 75%, 50%, and 25%) began changing colour when heated above 130 °C and transitioned continuously across the entire temperature range. The largest influence was on the trajectory of the observed colour change with predominant variation among inks in the b* coordinate in the CIELAB space. The findings of this research show that single-dye indicators are more suitable for industrial applications of critical temperature indicators where products must not exceed a certain temperature. Namely, no optimal blend was found that could replicate the sharp transitions of the single-dye indicators. Moreover, mixed-dye indicators did not even show any significant variance in measured colour difference as a function of temperature. Interestingly, colour transformation in the mixed-dye system starts at a lower temperature than expected from the single-dye indicators, suggesting that additional interactions between the compounds occur. The study further highlights the need for additional research to interpret those interactions and a better understanding of dye mixtures in irre-versible thermochromic inks. 538 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Almubarak, A. A., 2017. “The Effects of Heat on Electronic Components.” Int. J. Eng. Res. Appl. 7 (5): 52–57. Hunt, R. W. and Pointer, M. R. 2011. “Measuring Colour.” Chichester: John Wiley & Sons. Jenko, K., Rozman, N., Pogorelc, E., Stražar, P., Kunaver, M. and Klanjšek Gunde, M. 2021. “Development of hydrophobic protection layer for high-temperature irreversible thermochromics.” In Proceedings of the 2nd International Conference on Circular Packaging, edited by Igor Karlovits, 171–176. Slovenj Gradec: Pulp and Paper Institute, Faculty of Polymer Technology. Kulčar, R., Friškovec, M., Hauptman, N., Vesel, A. and Klanjšek Gunde, M. 2010. “Colorimetric properties of reversible thermochromic printing inks.” Dyes Pigm. 86: 271–277. Kulčar, R., Friškovec, M., Klanjšek Gunde, M. and Knešaurek, N. 2011. “Dynamic colorimetric properties of mixed thermochromic printing inks.” Color. Technol. 127: 411–417. Panák, O., Držková, M. and Kaplanová, M. 2015. “Insight into the evaluation of colour changes of leuco dye based thermochromic systems as a function of temperature.” Dyes Pigm. 120: 279–287. Panayiotou, G. P., Bianchi, G., Georgiou, G., Aresti, L., Argyrou, M., Agathokleous, R., Tsamos, K. M., Tassou, S. A., Florides, G., Kalogirou, S. and Christodoulides, P. 2017. “Preliminary assessment of waste heat potential in major European industries.” Energy Procedia. 123: 335–345. Pogorelc, E., Jenko, K. and Klanjšek Gunde, M. 2023. “Funkcionalne lastnosti temperaturnega indikatorja z ireverzibilno termokromno tiskarsko barvo.” Papir. 29: 38–41. Tadini, C. C. and Gut, J. A. 2022, “The Importance of Heating Unit Operations in the Food Industry to Obtain Safe and High-Quality Products.” Front. Nutr. 9:853638. Seeboth, A. and Lötzsch, D. 2013. “Thermochromic and Thermotropic Materials.” Boca Raton, FL: Taylor & Francis Group. White, M. A. and LeBlanc, M. 1999. “Thermochromism in Commercial Products.” J. Chem. Ed. 76 (9): 1201–1205. ADDITIONAL DATA ABOUT AUTHOR Corresponding author: Co-authors: Eva Pogorelc Marta KlanjšekGunde University of Ljubljana National Institute of Chemistry and Engineering 000, Ljubljana, Slovenia marta.k.gunde@ki.si Aškerčeva cesta 12 Faculty of Natural Sciences Hajdrihova 19 1000, Ljubljana, Slovenia Ondrej Panák National Institute of Chemistry +386 1 476 02 72 Hajdrihova 19 eva@mycol.si 1000, Ljubljana, Slovenia ondrej.panak@ki.si Raša Urbas University of Ljubljana Faculty of Natural Sciences and Engineering Aškerčeva cesta 12 1000, Ljubljana, Slovenia rasa.urbas@ntf.uni-lj.si 539 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION ENVIRONMENTALLY FRIENDLY COATINGS AND THEIR EFFECT ON THERMOCHROMIC PRINTING INK FUNCTIONALITY Teodora Lukavski1, Rahela Kulčar1, Marina Vukoje1, Katarina Itrić Ivanda1 1 and Tomislav Cigula 1 University of Zagreb, Faculty of Graphic Arts, Croatia Abstract: Polymer waste poses a significant environmental challenge due to its non-biodegradable nature, lead-ing to environmental pollution at the end of its lifecycle, meaning there is a pressing need to replace synthetic polymers with naturally derived ones. The introduction of circular economy practices is a solution to reduce waste materials by promoting waste reuse, particularly the agro-industrial waste. Protective coatings are crucial to en-hance functionality, stability, and product lifespan. Biodegradable coatings are a promising alternative. Thermo-chromic printing inks, which change color based on temperature, are especially sensitive to UV degradation and thus require protective coatings for durability. The integration of thermochromic inks with protective coating made from sustainable materials offers an innovative solution for producing eco-friendly graphic products that are both interactive and durable. This approach reduces the industry’s ecological footprint while delivering high-quality, functional products. Keywords: Thermochromic priting ink, coating, natural products, sustainability. 1. INTRODUCTION The challenge of today, which affects practically every aspect of industrial progress, is the excessive waste pro-duction, especially polymer material waste. Such waste cannot be recycled indefinitely, whereas, during recycling process new issues occur, including issues with sorting, cleaning, separation processes, high transportation and electricity costs; etc. and most of it ends up in landfills (Okan et al., 2019). It is voluminous and non-biodegradable. The goal of every industry should be to avoid producing waste at the end of the production process. Waste as a high-value raw material, can be reused, reducing natural resource destruction. Recognizing waste as an input raw material can lower the economic cost of these materials. When less virgin resource is used and post-consumed materials can be recycled or reused from easily accessible materials, packaging materials are considered susta-inable (Ibrahim et al., 2022). Industrial development in accordance with the circular economy is desirable and necessary. The food packaging industry is growing increasingly conscious of the development of intelligent and active biodegradable packaging (Bhargava et al., 2020) that achieves antioxidant, antimicrobial, and biocatalytic functions through the addition of bioactive components (Bastarrachea et al., 2015). Replacment of polymer ba-sed packaging solutions with paper based materials can be a promising sustainable alternative that reduces the environmental footprint. Certain drawbacks are expected in the terms of durability and strength of paper based materials, and thus by application of coatings, fiber reinforcement, lamination, and chemical treatment resistance to moisture, mechanical stress, and external factors can be used (Kunam et al., 2024). The coatings industry has been shifting toward using materials derived from renewable resources during the recent years and has significantly reduced VOC emissions over the past few decades, primarily by substituting solventbased coatings with waterbased coatings (Cunningham et al., 2019). The water-dispersive coating is free of volatile organic com-pounds that can cause a number of environmental issues and have a negative impact on people‘s health. In our case, the environmentally friendly bioactive coating is a water-dispersive (WD) coating enhanced with bioactive ingredients allantoin and ascorbic acid to improve the functionality of the coating. Ascorbic acid is a well-known antioxidant (Blokhina et al., 2003), and allantoin may also have antioxidant properties (Selamoglu et al., 2017). Antioxidants are molecules or compounds that donate electrons to free radicals in order to neutralize them. By neutralizing reactive oxygen species from both endogenous and exogenous sources, such as UV radiation, anti-oxidants added to coating work to stop photodegradation (Vukoje et al., 2024). Adding natural antioxidants could give these coatings functional qualities (Eça et al., 2014) such as enhanced physicochemical, mechanical, barrier, antioxidant, and antibacterial properties (Sultan et al., 2024). In addition to mechanical and chemical degradation, 540 29–30 May 2025, Ljubljana, Slovenia thermochromic (TC) printing inks are particularly susceptible to UV-induced degradation. One of the primary goals of adding bioactive compounds was to reduce UV-induced degradation, since UV exposure is known to reduce the ink‘s thermochromic effect. Thermochromic printing inks are characterized by their ability to change color in response to temperature changes. Thermochromic printing inks have grown in significance for a variety of graphic art applications, including smart packaging, security printing, and marketing activities that aim to highlight a pro-duct‘s value or distinctiveness (Kulčar et al., 2010). Agro-industrial waste is ideal for paper production because it contains a significant amount of cellulose fibers. Non-wood lignocellulosic materials derived from citrus waste offer a viable substitute for traditional raw materials used to make paper and packaging (Vukoje et al., 2021). Since environmentally friendly coatings are a novel, eco friendly approach to current technology, it is necessary to observe the effects of these coatings in order to make improvements over time. Their development could eventu-ally have a significant positive influence on the advancement of technological processes. Due to the fact that there aren‘t many research papers on this specific subject, we attempted to apply the concepts we learned from the food packaging and coatings industry to the graphic industry by creating a environmentally friendly coating with added bioactive compounds for printing on paper. The graphic industry has recognized the waste issue, which can be resolved by a more thoughtful selection of materials that enter the process. This study will concentrate on preliminary tests of one step of the process, particularly regarding the use of environmentally friendly coatings and their impacts on the functionality of thermochromic printing inks and the thermochromic effect. 2. EXPERIMENTAL 2.1. Printing substrate and printing ink For this research, a pressure sensitve label (PSL) based on citrus agro-industrial byproducts was used as a prin-ting substrate. The upper layer of the label was produced with a 20% reduction in CO2 emissions (Avery Denni-son, 2025). The label‘s composition includes 15% citrus fibers, 40% recycled paper, and 45% virgin wood pulp, ensuring high-quality natural paper. The reversible thermochromic ink used is a commercially available leuco dye-based screen printing ink with an activation temperature (T ) of 28°C. Before reaching the T , the TC print is coloured in orange. By heating up A A and reaching the T , the TC print changes its coloration to a neon yellow. This type of ink is also known as body A heat activated because it changes color when exposed to human body temperature. Thermochromic inks with this activation temperature are commonly used in interactive packaging, temperature indicators on drinkware, novelty items, and security printing. Printing was carried out under laboratory conditions using a semi-automatic screen-printing device from Holzschurer KG, Wuppertal. A mesh with a density of 62 threads/cm was used for the printing process. The prints were produced in full tone. 2.2. Coating preparation Weighing out 0.0440 g of ascorbic acid and adding distilled water until the total volume reached 25 mL produced the ascorbic acid solution, which had an initial concentration of 0.01 M. To make the allantoin solution, which had an initial concentration of 0.01 M, 0.0395 g of allantoin was weighed, and distilled water was added until the total volume reached 25 mL. Ascorbic acid and allantoin 0.01 M solutions were diluted to 0.08 mM for analysis in quartz cuvettes by mixing 20 µL of the bioactive component solution with 2480 µL of distilled water. To make the wa-ter-dispersive coating solution, 10 µL of pure water-dispersive coating was diluted with 100 mL of distilled water. The commercially available water-dispersive coating was mixed with bioactive components L-ascorbic acid (Sig-ma-Aldrich, Merck, Germany), also referred to in the text as plainly ascorbic acid, and allantoin (Sigma-Aldrich, Merck, Germany) at a concentration of 0.25% to improve the performance of the coating. A magnetic stirrer (IKA RCT basic IKAMAG® safety control, Germany) was used to mix the ascorbic acid and wa-ter-dispersive coating solution which was stirred for three hours at 400 rpm on a magnetic stirrer with periodically heating up to 50°C for 5 minutes every hour. The allantoin and water-dispersive coating solution was stirred for 10 minutes at 400 rpm on a magnetic stirrer without heating. The samples that had a pre-printed reversible ther-mochromic orange-neon yellow color were coated with a coater (RK K control coater, UK), a wire wound bar with 541 29–30 May 2025, Ljubljana, Slovenia a 0.30 mm wire thread, producing a layer of 24 µm thick film. The uncoated and coated TC prints were exposed to UV radiation (Solarbox 1500e, CO.FO.ME.GRA, Italy) for 5, 10 and 15 hours at 50°C and 550 W/m2. 2.3. UV-Vis spectroscopy For the determination of UV apsorption potential, UV-Vis spectroscopy was used. The absorbance of pure wa-ter-dispersive coating solution and water-based solutions with bioactive components ascorbic acid and allantoin was measured using a UV-Vis spectrophotometer (Shimadzu, UV-1900 i, Japan) in the UV-Vis range of 190-1100 nm. 2.4. Color determination Spectral reflectance was recorded using an Ocean Optics USB2000+ spectrometer equipped with a 30 mm wide integrating sphere, operating under an (8: di) measuring geometry. The printed samples were subjected to heating and cooling on a full-cover water block (EK Water Blocks, EKWB d.o.o., Slovenia). Measurements were taken at 1 nm intervals across the spectral range of 370–730 nm. Ocean Optics SpectraSuite software was utilized to compute the CIELAB values from the obtained reflectance data. The total color difference between printed PSL samples at 20°C and 40°C was determined using the CIEDE2000 formula (CIE Central Bureau, 2004). 3. RESULTS AND DISCUSSION Figure 1. shows the absorption spectra of three different water-based solutions— WD coating (blue line), allantoin (orange line), and ascorbic acid (pink line)—in the UV-Vis region. The x-axis represents the wavelength in na-nometers (nm), ranging from approximately 200 to 450 nm, while the y-axis indicates absorbance, showing how much light each substance absorbs at different wavelengths. WD coating exhibits strong absorption below 250 nm, suggesting high absorbance in the UV region. Allantoin shows a peak absorption between 200 and 250 nm, with a rapid decrease at higher wavelengths. Ascorbic acid has a distinct absorption maximum around 260 nm, which is characteristic of this compound. The absorption spectra suggest that ascorbic acid may contribute to UV radiation blocking when combined with WD coating. WD coating exhibits strong absorption below 250 nm, while ascorbic acid shows a distinct absorption peak around 260 nm, where the absorption of WD coating decreases. This indicates that their combination could enhance overall UV protection by covering a broader range of the UV spectrum. 4.0 3.5 WD coating allantoin 3.0 ascorbic acid e 2.5 banc or 2.0 Abs 1.5 1.0 0.5 0.0 200 250 300 350 400 450 Wavelength (nm) Figure 1. UV-Vis absorption spectra of water-based solutions - WD coating, allantoin, and ascorbic acid Figure 2. shows the spectral reflectance curves of the unprinted PSL substrate and the thermochromic print, mea-sured at two different temperatures, 20°C and 40°C. The Figure 2. illustrates how the reflectance properties of the thermochromic ink change with temperature, highlighting the ink’s ability to undergo color shifts. 542 29–30 May 2025, Ljubljana, Slovenia 100 80 e 60 % tanc lec Ref 40 20 PSL TC print at 20°C TC print at 40°C 0 400 450 500 550 600 650 700 Wavelength (nm) Figure 2. Spectral reflectance curve of the unprinted PSL substrate and the TC print, measured at two different tempera- tures 35 Uncoated WD coating 30 WD+ascorbic acid WD+allantoin 25 20 E2000 ED 15 CI 10 5 0 5 10 15 Exposure time (h) Figure 3. CIEDE2000 measured on TC prints with different solutions containing bioactive compounds in WD coatings at 20°C The influence of different WD coatings with added bioactive compounds on the colour stability of thermochromic prints under UV exposure over time, with the sample colour observed at 20°C, is illustrated in Figure 3. The results indicate that coated samples exhibit lower colour differences (CIEDE2000) compared to the uncoated sample, suggesting that the applied coatings contribute to maintaining the thermochromic effect. At 5 hours of UV expo-sure, all coated samples show a reduced degree of colour change, highlighting their initial protective role. This trend continues at 10 hours, where the coatings still demonstrate their ability to slow down the degradation of the thermochromic effect. Even at 15 hours of exposure, coated samples maintain a slightly lower colour difference than the uncoated sample, demonstrating that coatings help extend the functionality of thermochromic prints. 543 29–30 May 2025, Ljubljana, Slovenia 35 Uncoated 30 WD coating WD+ascorbic acid WD+allantoin 25 E2000 20 ED 15 CI 10 5 0 0 5 10 15 Exposure time (h) Figure 4. Total color contrast (TCC) between samples at 20°C and 40°C as a function of exposure time The total color contrast (TCC) between samples at 20°C and 40°C is presented as a function of exposure time (Fi-gure 4). A TC sample is considered effective if the TCC remains clearly visible. Comparing uncoated and coated samples, it is evident that coatings contribute to the prolonged functionality of thermochromic prints. Comparing the values of uncoated samples with those coated with various bioactive compounds reveals the protective effect of the coatings. The initial values (0 h) show that all coatings enhance the total color contrast compared to uncoa-ted samples, indicating that coatings intensify the thermochromic effect. Dailliez et al. demonstrated that applying a smooth transparent layer to halftone prints darkens the print and enhances its color saturation. This effect occurs due to the lateral propagation of light within the coating during multiple reflections between the printed diffusing substrate and the coating–air interface (Dailliez et al., 2021). As exposure time increases, TCC values decrease for all samples, reflecting the gradual degradation of the thermochromic effect due to UV exposure. However, coated samples experience a significantly slower reduction in contrast than uncoated samples, confir-ming the protective function of coatings. After 5 hours of UV exposure, coated samples retain a higher color con-trast than uncoated samples, emphasizing their effectiveness in slowing degradation. By 10 hours, the difference between coated and uncoated samples remains noticeable, although the overall contrast continues to decrease. After 15 hours of exposure, all samples exhibit very low TCC values, indicating substantial degradation of the thermochromic effect. However, coated samples still maintain slightly higher contrast values than the uncoated sample. This analysis demonstrates that coatings with added bioactive compounds not only enhance the initial thermochromic effect but also slow its degradation over time. These findings suggest that such coatings could be valuable for extending the longevity of thermochromic prints, offering potential applications in smart packaging, security printing, and interactive design. 4. CONCLUSION The goal of our research was to incorporate bioactive compounds, ascorbic acid and allantoin, into commercially available water-dispersive coating to enhance overall UV protection by covering a broader range of the UV spectrum. The results indicate that one or more of the ingredients in commercially available water-dispersive coating, that we used as the base, may have an impact on the inhibition of the UV blocking effect of the bioactive compounds in our coating, since the exact composition of commercially available coatings is not entirely known. According to the results, we believe the initial idea is valid and promising. Future research will focus on developing initial coating formulation so that we can better regulate the interactions between the components. Our research group’s objective is to develop and alter formulations to produce an environmentally friendly paper coating that maximizes the use of additional bioactive compounds. It is clear from the UV-Vis absorption spectra that the bioactive compounds exhibit a beneficial effect, — in other words, protection in the UV portion of the spectrum, 544 29–30 May 2025, Ljubljana, Slovenia when analysed separately. The colorimetric analysis results also demonstrate the beneficial impact of bioactive compounds on the coating itself, as the coatings maintain and improve the thermochromic effect properties. 5. ACKNOWLEDGMENT This work was carried out as part of the project IP-2022-10-3864: Improvement of Packaging Products through the Application of Environmentally Friendly Materials and Inclusive Design. 6. REFERENCES Avery Dennison. (2025). BT024 rCRUSH BARLEY FSC S2030-BG45WH FSC_EN. Bastarrachea, L. J., Wong, D. E., Roman, M. J., Lin, Z., & Goddard, J. M. (2015). Active packaging coatings. In Coatings (Vol. 5, Issue 4, pp. 771–791). MDPI AG. https://doi.org/10.3390/coatings5040771 Bhargava, N., Sharanagat, V. S., Mor, R. S., & Kumar, K. (2020). Active and intelligent biodegradable packaging films using food and food waste-derived bioactive compounds: A review. In Trends in Food Science and Technology (Vol. 105, pp. 385–401). 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International Symposium on Graphic Engineering and Design. https://doi.org/10.24867/GRID-2024-p50 545 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHOR Corresponding author: Co-author(s): Teodora Lukavski Marina Vukoje Katarina Itrić Ivanda Faculty of Graphic Arts Faculty of Graphic Arts Faculty of Graphic Arts Getaldićeva 2 University of Zagreb University of Zagreb University of Zagreb Getaldićeva 2 Getaldićeva 2 10000 Zagreb, Croatia 10000 Zagreb, Croatia 10000 Zagreb, Croatia marina.vukoje@grf.unizg.hr katarina.itric.ivanda@grf.unizg.hr teodora.lukavski@grf.unizg.hr Rahela Kulčar Tomislav Cigula University of Zagreb University of Zagreb Faculty of Graphic Arts Faculty of Graphic Arts Getaldićeva 2 Getaldićeva 2 10000 Zagreb, Croatia 10000 Zagreb, Croatia rahela.kulcar@grf.unizg.hr tomislav.cigula@grf.unizg.hr 546 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION THE VISUAL APPEARANCE OF PEARLESCENT PIGMENTS COATED WITH CELLULOSE NANOCRYSTAL (CNC) BINDER Mirica Karlovits1, Urška Kavčič2, Blaž Likozar1 and Uroš Novak1 1National Institute of Chemistry, Slovenia 2Pulp and Paper Institute, Slovenia Abstract: Pearlescent pigments are widely used in coatings, cosmetics, and packaging to achieve unique optical effects. This study investigates the visual appearance of pearlescent pigments coated with a cellulose nanocrystal (CNC) binder, focusing on how CNC affects their color and optical properties. In this study, three types of pearlescent pigments with different particle size but with the same color, form, type and pigment base were used. The coating was formulated in such a way that the pearlescent pigments were mixed with CNC binder in a ratio of 20:100. The paper was coated in two layers in machine direction. The color and optical properties, including color travel, flop index and print gloss, were analyzed using multi-angle spectrophotometry, gloss measurements and microscopy. The results show that the size of the pigments has an influence on color lightness and chrome, with the pigment with the smallest particle size achieving the highest values. The pigment with the largest particles achieved the highest values for the flop index and print gloss. These findings highlight CNC’s potential as a sustainable binder for advanced pigment applications. Keywords: Pearlescent pigments, cellulose nanocrystals (CNC), coating, print gloss, flop index. 1. INTRODUCTION The development of environmentally friendly and sustainable packaging materials is a major challenge for the packaging industry. With its excellent physical and chemical properties, including renewability, degradability, sound mechanical properties, and good biocompatibility, nanocellulose is promising for use in various applications (Xu, 2024). Cellulose nanomaterials (CNs) are of increasing interest due to their appealing inherent properties such as biodegradability, high surface area, light weight, chirality and the ability to form effective hydrogen bonds across the cellulose chains or within other polymeric matrices (Tayeb, 2018). All cellulosic materials with at least one dimension on the nanometric scale are referred to as nanocellulose (Lengowsk, 2023). Nanocellulose is a kind of cellulose-derived natural fiber at the molecular level, and can be obtained from lignocellulosic materials, marine animals, bacteria, and algae through extraction methods. Differences in extraction techniques and sources of cel-lulose fibers have significant influence on the characteristics of nanocellulose. Compared with ordinary cellulose, nanocellulose presents a variety of features, including a high Young’s modulus, high crystallinity, high specific surface area, high tensile strength, and other special traits, suggesting promising prospects for application in the fields of papermaking, biomedicine, materials packaging, coating, etc. (Xu, 2024). Nanocellulose is a rod-like nanoparticle that can be categorized into three main groups based on its microphology, size and raw material source: cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial nanocellulose (BNC) (Hu, 2021). CNCs, also known as “cellulose whiskers”, “cellulose nano-whiskers” and “nanocrystalline cellulose”, have structural dimensions in nanoscale width and length. The cellulose sources include bacterial cellulose, cot-ton, ramie, tunicate, soft wood and hard wood, etc. Although the sources of CNCs are different, the rod-like CNCs display a high surface area with a high amount of hydroxyl groups that give CNCs some extra natural properties, such as hyperfine structure, high transparency, high purity, high crystallinity, high strength and Young’s modu-lus, and high reactivity. These properties differ greatly from those of the regular cellulosic fibers, which enables CNCs to extend more widespread applications (Xie, 2018). CNCs are mainly extracted from cellulosic materials through acid hydrolysis, in which the amorphous region dissociates, and then rod-like nanocrystals with strong acid resistance and high crystallinity will be formed. CNFs, as a type of nanocellulose, are obtained by a strong mechanical disintegration treatment owing to the complex structure of cellulose fibers. BNC, which is a term for nano-structured cellulose created by bacteria, is cultured in nutrient medium containing carbon sources. Although 547 29–30 May 2025, Ljubljana, Slovenia these categories vary from each other, they are some-how connected in that many nanocellulose sources coexist in an extensive and overlapping material space (Xu, 2024). Table 1: The types and characteristics of nanocellulose. Types Other Nomenclature Micro-morphol- Typical Average Size Preparation ogy Sources Method Cellulose Cellulose whiskers nanocrystals (CNWs), cellulose Plants Diameter: 50- (CNCs) nanocrystalline Whiskers, (wood, cotton, 70 nm Acid hydrolysis (CNC), rod-shaped hemp, flax, Length: nanocrystalline etc.) 100-250 nm cellulose (NCC) Cellulose Micro-fibrillated Twisted Plants Diameter: nanofibrils cellulose (MFC), filamentous (wood, beet, 5-60 nm Mechanical (CNFs) nano-fibrillated cotton, hemp, Length: treatment cellulose (NFC) flax, etc.) Several micrometers Bacterial Bacterial cellulose Gel-like, Acetobacter, Diameter: 20- nanocellulose (BC), regenerated ribbon-like xylinum, 100 nm Bacterial synthesis (BNC) bacterial cellulose pasteurii, etc. Length: (RBC) unfixed The main differences between CNC and CNF are their dimension and crystallinity. CNFs consist of mixtures of amorphous and crystalline cellulose chains with length of up to several microns, while CNCs are highly crystalline with length typically less than 500 nm. Both materials have immense potential for various applications, and this review will focus on cellulose nanocrystals (Grishkewich, 2017). CNCs are spindle-like nanometer-scale materials with unique properties such as high strength, high specific surface area, high thermal stability, optical transparen-cy, biodegradability, biocompatibility, and self-assembly capability (Xu, 2021). Because nanocellulose is obtained from plant biomass, it is chemically compatible with paper and its application does not alter the paper’s characteristics, reduce its biodegradability, or make it more dangerous to human health (Lengowsk, 2023). 2. EXPERIMENTAL In this study, a commercially available cellulose nanocrystals “CNCs” (Table 2) as a binder (Manufacturer: Nano-crystacell) and three types of pearlescent pigments by Eckart (Germany) were used. All three pigments have the same color shade, the form, the same pigment base and differ only in their particle size (Table 3). Matte black paper with a grammage of 130 g/m2 was used as a substrate (Manufacturer: Bringmann). The coating formulation was based on pearlescent pigments mixed with cellulose nanocrystals (CNCs) at a ratio of 20:100. The paper was coated in machine direction using a K Control Coater / meter bar coating (wire diameter: 0.05 mm, wet film deposit: 4 μm). In the double-layer coating, the second layer was added after air drying the first layer. The samples were finally placed in standard conditions of 23 °C and 50% humidity for one day. The MA-T12 handheld multi-spectrophotomer (X-Rite) was used to measure the lightness (L*) and chroma (C*) of pearlescent pigments coated with CNC binder (CIE D50 standard illumination) measured at 45as-15°, 45as15°, 45as25°, 45as45°, 45as75°, 45as110°. The print gloss was measured at three different angles (20°, 60°, 85°) using Gloss Meter (Rhopoint IQ). Measure-ments conform to the ASTM D523 standard measurement protocol for specular gloss measurements. Gloss is 548 29–30 May 2025, Ljubljana, Slovenia measured in gloss units (GU). Table 2: Properties of cellulose nanocrystals (CNCs). Parameter Specification Chemical name C O H 6 510 Color White-translucent Form Aqueous suspension, 2-5wt.% solids Surface Hydrophilic Average size (Scherrer method, SEM) 10-15 nm wide,150-300 nm length Crystallinity (XRD:Segal method) 90,3% Initial decomposition temperature (DTGA in N2) 285 °C Density Aqueous gel: 1.04 g/cm3 Lignin content Negligible Figure 1 shows SEM image of the cellulose nanocrystals (CNCs) and Table 3 shows the properties of the pearlescent pigments used in this study. Figure 1: SEM image of the cellulose nanocrystals (Nanocrystacell (2023). Table 3: Properties of the pearlescent pigments. Properties SYMIC A001 SYMIC C001 SYMIC E001 (Pigment P1) (Pigment P2) (Pigment P3) Color shade Interference silver Interference silver Interference silver Form Powder Powder Powder Pigment type Pearlescent pigment Pearlescent pigment Pearlescent pigment Pigment base Synthetic Mica Synthetic Mica Synthetic Mica Particle size (μm) 1-15 10-40 20-150 3. RESULTS WITH DISCUSION Lustre and hiding power of the pigments in the application system are two most important properties influenced by particle size distribution. A frequently used classification distinguishes five classes of the particle size distribution: M (1 to 15 μm), F (5 to 25 μm), N (10 to 50 μm), S (10 to 130 μm), and L (40 to 200 μm). As a rule, the larger the particles the better the lustre, the smaller the particles the better the hiding power. The large particles provide a large smooth surface and an undisturbed reflection of the incident light, resulting in an excellent gloss and high 549 29–30 May 2025, Ljubljana, Slovenia brilliance. The smaller particles result in a less smooth surface, more edges and corners, greater scattering and reflection and therefore better opacity. (Glausch, 1998). As shown in Figure 2, the pigment particles differ in size, with the particle size for P1 ranging from 1 to 15 μm, for P2 from 10 to 40 μm, and for P3 from 20 to150 μm. Figure 2: SEM images of P1, P2 and P3 particles (from left to right). Characterising special effect pigments requires angle-dependent spectrophotometric testing. The color dynam-ics resulting from the combination of geometries and pigments can be illustrated by color changes (also known as color travel). Figure 3 shows color travel through lightness (L*) and chroma (C*) changes of P1, P2 and P3 pigments coated with CNC binder. The highest values of lightness (Figure 3, right) were observed at all three pig-ments at 45as-15° (P1: L*=125, P2: L*=107, P3: L*=119), meanwhile the smallest values of lightness at 45as110° (P1: L*=56, P2: L*=29, P3: L*=26). If we compare the lightness values for all three pigments, we see that the values for P1 are the highest. Color travel through chroma are shown in Figure 3 (left). All three pigments exhibit a similar overall trend, with a peak at the beginning, a significant dip in the middle, and a rise again towards the end. The chroma values are highest at 45as15° and 15as15° , indicating strong color intensity in these conditions. The lowest chroma value appear at 45as75° for P3 (P3: C*=2.6). Pigment P3 demonstrates the most pronounced variation. Figure 3: Color travel through lightness (L*) and chroma (C*) changes of P1, P2 and P3 pigments coated with CNC binder. The flop (also known as Travel or Two-Tone) is probably the most commonly known optical property of effect pigments and is often simply called the metallic effect. This is understood as the alteration of the brightness as a function of observation angle. This change in brightness can easily be determined visually, observing the test panel on face and after that at oblique angles. In reality, the flop is evaluated by inspection at different angles, in some cases also a change in color can be found (color-flop). The color-flop can only be found at pearlescent pigments and in a few cases of advanced effect pigment technology. The observational angles are grouped into three categories: “Face” (near specular: 15º or 25º), “Mid Specular” (or diffuse: 45º), and “Flop” (far specular: 75º or 110º). An angle of 25º [=L*(25º)] has become accepted to describe the visual effect on face. Often angles closer to the reflected light (“nearer to the gloss”) are used. If for example, measurements are taken at an angle of 15º [=L*(15º)], the accuracy of the measurement will be less as the measurement is “nearer the gloss”. Other angles 550 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia used are 110º [=L*(110º)] and 70º, which measure the darker appearance on flop. Besides an intermediate angle around is common 45º [=L*(45º)]. From three color measurement values the flop index can be mathematically calculated. This allows pigments to be characterized and compared with each other. For the observed changes in intensity is given by the flop index. The flop index (FI) is the measurement of the change in reflectance of a each other . For the observed changes in intensity is given by the flop index. The flop index (FI) is the metallic color as it is rotated through the range of viewing angles. A flop index of 0 indicates a solid color, while a measurement of the change in reflectance of a metallic color as it is rotated through the range of viewing very high flop metallic basecoat color may have a flop index of 15-17. The flop index (FI) is mathematically defined angles. A flop index of 0 indicates a solid color, while a very high flop metallic basecoat color may have by the following formula: a flop index of 15-17. The flop index (FI) is mathematically defined by the following formula: 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 = 2.69 × ∗ 0.86 ( ( ∗ ∗ 1.11 𝐿𝐿𝐿𝐿 15 − 𝐿𝐿𝐿𝐿 110) 𝐿𝐿𝐿𝐿 45) Figure 4 Figure 4 (right) shows the calculated flop index (FI) of all three pigments coated with CNC binder. The flop index (right) shows the calculated flop index (FI) of all three pigments coated with CNC binder. The increased with the particle size, with pigment P3 having the largest particle size (20-150 μm). The lowest flop in flop index increased with the particle size, with pigment P3 having the largest particle size (20-150 μ m). -dex was found for pigment P1, where the FI=6.4. The higher the value of FI, the greater the effect. In other words, The lowest flop index was found for pigment P1, where the FI=6.4. The higher the value of FI, the greater the higher the flop index result (FI), the higher the change in reflectance of a metallic color as it is rotated through the effect. In other words, the higher the flop index result (FI), the higher the change in reflectance of a But if it changes substantially, a high value might come in at 15 plus from all angles, then the value of FI would be 0. But if it changes substantially, a high value might come (Debeljak, 2010; Wiβling, 2008) in at 15 plus various viewing angles. If the colour of the print looks the same from all angles, then the value of FI would be 0. metallic color as it is rotated through various viewing angles. If the colour of the print looks the same (Debeljak, 2010; Wiβling, 2008). Figure 4: Figure 4: Flop index and print gloss of P1, P2 and P3 pigments coated with CNC binder. Flop index and print gloss of P1, P2 and P3 pigments coated with CNC binder. Gloss is an important optical property assessing the print quality. The gloss perception describes the geometry-de Gloss is an important optical property assessing the print quality. The gloss perception describes the -geometry-dependent properties of a surface. The visual appearance attribute called specular gloss pendent properties of a surface. The visual appearance attribute called specular gloss describes the perceived describes the perceived luminance caused by specular reflection on the surface. A typical example for luminance caused by specular reflection on the surface. A typical example for a surface with a high specular gloss a surface with a high specular gloss is a mirror (Kehren, 2013; Sharma 2022). As can be seen in Figure is a mirror (Kehren, 2013; Sharma 2022). As can be seen in Figure 4 (left), the print gloss increased with the parti-4 (left), the print gloss increased with the particle size, as did the flop index. The pigment P3 coated with cle size, as did the flop index. The pigment P3 coated with CNC binder achieved the highest print gloss (GU=5.9), CNC binder achieved the highest print gloss (GU=5.9), followed by pigment P2 (GU=5.4) and the lowest followed by pigment P2 (GU=5.4) and the lowest pigment P1 (GU=1.9). pigment P1 (GU=1.9). 4. CONCLUSIONS 4. CONCLUSIONS Cellulose nanocrystals (CNC) are used in various applications due to their exceptional mechanical properties, bio Cellulose nanocrystals (CNC) are used in various applications due to their exceptional mechanical -degradability, and optical characteristics. In coatings, CNCs serve as sustainable binders that enhance pigment properties, biodegradability, and optical characteristics. In coatings, CNCs serve as sustainable binders stability and improve optical effects. The results demonstrate that pigment particle size significantly influences that enhance pigment stability and improve optical effects. The results demonstrate that pigment particle color lightness, chroma, flop index, and print gloss. Smaller pigment particles produced higher lightness and size significantly influences color lightness, chroma, flop index, and print gloss. Smaller pigment particles can be successfully used as a binder for coatings with effect pigments and represents a sustainable alternative print gloss. These results suggest that CNC can be successfully used as a binder for coatings with effect pigments and represents a sustainable alternative to synthetic binders. The study highlights CNC’s chroma values, while larger particles exhibited greater flop index and print gloss. These results suggest that CNC produced higher lightness and chroma values, while larger particles exhibited greater flop index and paving the way for further research into optimizing CNC formulations for tailored optical effects. Their versatility potential for applications in coatings, packaging, and printing, paving the way for further research into to synthetic binders. The study highlights CNC’s potential for applications in coatings, packaging, and printing, makes them a promising material for developing eco-friendly and high-performance products in numerous fields. optimizing CNC formulations for tailored optical effects. Their versatility makes them a promising material for developing eco-friendly and high-performance products in numerous fields. 551 5 29–30 May 2025, Ljubljana, Slovenia 5. ACKNOWLEDGMENTS The authors would like to acknowledge the financial support of Horizon Europe projects UPSTREAM (GA 101112877), REMEDIES (GA 101093964) and the financial support of the Slovenian Research Agency through the Program P2-0152. 6. REFERENCES Debeljak, M. (2011) ‘Obstojnost sistetičnih papirjev potiskanih s specialnimi tiskarskimi barvami’, PH diss., University of Ljubljana, pp. 12-15. Glausch, R. et al. (1998) ‘Special Effect Pigments’, Hannover: Vincentz, p. 31. Grishkewich, N. et al. (2017) ‘Recent advances in the application of cellulose nanocrystals’, Current Opinion in Colloid & Interface Science, 29, pp. 32–45. Available at: https://doi.org/10.1016/j.cocis.2017.01.005. Hu, F. et al. (2021) ‘Cellulose nanofibrils (CNFs) produced by different mechanical methods to improve mechanical properties of recycled paper’, Carbohydrate Polymers, 254, p. 117474. Available at: https://doi.org/10.1016/j.carbpol.2020.117474. Kehren, K. (2013) ‘Optical properties and Visual Appearance of Printed Special Effect Colors’, PH diss., Technischen Universität Darmstadt, pp. 23-50. Lengowski, E.C. et al. (2023) ‘Nanocellulose Coating on Kraft Paper’, Coatings, 13(10), pp. 1705–1705. Available at: https://doi.org/10.3390/ coatings13101705. Nanocrystacell (2023). Available at: https://www.nanocrystacell.eu/?lang=sl (Accessed: 18 February 2025). Sharma, B. et al. 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ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Mirica Karlovits Urška Kavčič Hajdrihova 19 Bogišićeva 8 1000 Ljubljana National Institute of Chemistry Pulp and Paper Institute 1000 Ljubljana Slovenia Slovenia urska.kavcic@icp-lj.si mirica.karlovits@ki.si Blaž Likozar National Institute of Chemistry Hajdrihova 19 1000 Ljubljana Slovenia blaz.likozar@ki.si Uroš Novak National Institute of Chemistry Hajdrihova 19 1000 Ljubljana Slovenia uros.novak@ki.si 552 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION COLOUR STABILITY OF REVERSIBLE THERMOCHROMIC COMPOSITE Katarina Jenko1,2, Marta Klanjšek Gunde2,3, Ondrej Panák2,3 and Raša Urbas1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2Mysteria Colorum – MyCol d.o.o., Slovenia 2National Institute of Chemistry, Ljubljana, Slovenia Abstract: Reversible thermochromic (TC) composites generally contain a leuco dye, a colour developer and a solvent. In such composites, the leuco dye can be in a coloured or colourless state. However, the colour stability of some TC composites is poor with certain compositions of substances and better with others. To gain an insight into this phenomenon, a TC composite consisting of the leuco dye crystal violet lactone (CVL), the developer ben-zyl 4-hydroxybenzoate (B4HB) and the solvent octadecan-1-ol (OD) was investigated. The stability of the colour was examined in the coloured state for the entire (ternary) composite and the binary composite containing only the dye and the developer. The freshly prepared samples and the samples aged for one month were analysed using FTIR and UV-VIS spectroscopy. The UV spectra showed some changes in the electronic transitions between the freshly prepared and the aged binary TC composite. For the ternary TC composite, the results after one month showed not only a colour change, but also a change in the characteristic peaks in the FTIR spectrum. Keywords: reversible thermochromic composites, colour complex, colour stability, crystal violet lactone 1. INTRODUCTION TC composites generally contain three basic components: a leuco dye, a developer, and a solvent (White, 1999; Seeboth, 2008). The leuco dye can be in a colourless or coloured state, depending on the charge in the environ-ment. The most commonly used colour developers are bisphenol A, gallates, phenols or weak acids. They are responsible for the reversible colour change and also for the colour intensity of the end product (TC composites). The third component is a weakly polar solvent, usually an alcohol or an ester. The solvents are responsible for the reversible temperature-dependent colour change of the TC composites. The melting point of the weakly polar solvent is the control point at which a colour change can be expected. TC composites are usually prepared by melting the solvent and dissolving the dye and developer in the liquid sol-vent (Hajzeri, 2015). The liquid TC composite is generally colourless, but when it cools and solidifies, it becomes coloured. Normally, a TC composite contains the largest amount of solvent, followed by the developer, and the least amount of leuco dye. When the TC composite is heated above the melting point of the solvent, it liquefies so that the leuco dye and developer dissolve in it, and the composite becomes discoloured. When the TC composite cools below the melting point and solidifies, it becomes coloured. This paper presents a study on the stability of TC composites made of developer and leuco dye with and without solvent. The structural and optical changes of such a TC composite over time were analysed while the samples were stored in a dry and dark place at room temperature for one month. The samples were analysed by Fouri-er-Transform Infrared Spectroscopy (FTIR) and ultraviolet-visible (UV-VIS) spectroscopy. Leuco-dye molecules are expected to undergo the strongest changes in the presence of coloured centres, i.e. the open lactone ring. The main aim of the research is to investigate the ability of the applied analytical method, FTIR or UV-VIS, to monitor such changes. 553 29–30 May 2025, Ljubljana, Slovenia 2. MATERIALS AND METHODS 2.1 Samples Basic components were used for the preparation of TC composites: the leuco dye crystal violet lactone (CVL), the developer benzyl 4-hydroxybenzoate (B4HB) and the solvent octadecan-1-ol (OD). When CVL and B4HB are ground together with a mortar and pestle, a relatively strongly coloured powder is obtained. Even mixing the two components leads to charge transfer between B4HB and CVL, which opens the lactone ring of the dye. This effect does not occur if we mix the two powders without pressure. The colouring effect is strong after heating the powder mixture. When the CVL+B4HB+OD mixture is heated above the melting point of OD, OD liquefies so that CVL and B4HB can dissolve in it. In this work we have investigated how this colouring changes over time. The effect of the heating temperature was observed by heating one part of the TC composite to 70 °C, which is well above the melting point of OD (58 °C). The second part was heated to 110 °C, which corresponds to the melt-ing point of B4HB. The binary TC composite of B4HB and CVL was also prepared in two different ways. Firstly, the mixture was heated to 70 °C and the dye was mixed with the developer to form a coloured complex. Secondly, the mixture was prepared using a pestle and mortar, where only the physical contact of the powder particles was sufficient for colouration. The colour stability of the three-component TC composite of OD, B4HB and CVL was compared with the colour stability of the binary TC composite of B4HB and CVL. All samples prepared in this study are listed in Table 1. The samples were aged on the laboratory counter for one month at room conditions, protected from direct sunlight and dust. Fresh and aged samples were analysed using selected methods, which are described in detail in chapter 2.2. Four different samples were prepared with the basic components mentioned above. The samples were analysed fresh and aged for one month. A total of eight samples were analysed (Table 1): • solvent + developer + dye (the solvent is melted during the preparation of the composite), • solvent + developer + dye (the solvent and developer are melted during the preparation of the compos- ite), • developer + dye (thermal activation; heating), • developer + dye (mechanical activation; using mortar and pestle). Table 1: Description of laboratory-prepared samples, a total of 8 samples (4 fresh and 4 aged). Sample Mass ratio of basic Type of activa- Basic components Preparation components tion 4A Solvent + developer + leuco dye 4 : 2 : 1 Heated to 70°C Thermal 4B Solvent + developer + leuco dye 4 : 2 : 1 Heated to 110°C Thermal 5A Developer + leuco dye 2 : 1 Heated to 70°C Thermal 6T Using mortar and Developer + leuco dye 2 : 1 Mechanical pestle 2.2 Measurements All samples were measured with the UV-VIS spectrometer and the ATR FTIR spectrometer. Samples 4A and 4B were additionally measured with the spectrometer i1. UV-VIS spectra were recorded using a Lambda 950 spectrometer (PerkinElmer) with an integrating sphere. Solid samples were ˝scraped˝ with a spatula to obtain a powder. All samples were prepared for transmittance measurement. For this purpose, the scraped powder was applied to a quartz slide and inserted into the inlet of the integrating sphere. The parameters were set using the UV WinLab programme: ordinate output (%T), measurement range 2500–250 nm and 5 nm step. The FTIR ab-sorption spectra were recorded with a Tensor 27 FTIR spectrometer. The parameters were set using the Opus 8.5 programme: measuring range (500–4000 cm-1), resolution (4 cm-1) and number of scans (64). The 4A and 4B were measured at 12 locations with the spectrometer i1 and the average values were taken into account in the evaluation. The colour coordinates L*, a*, b* were determined from the measured R spectra (D65, 2 °standard observer) using BabelColor PatchTool. 554 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 3. 3. RESULTS WITH DISCUSSION RESULTS WITH DISCUSSION Figure 1 shows photos of fresh and aged samples. After one month, the colours of samples 5A and 6T fade. After Figure 1 shows photos of fresh and aged samples. After one month, the colours of samples 5A and 6T a certain time, they become lighter (the effect is most obvious on the surface of the coloured powder of the aged fade. After a certain time, they become lighter (the effect is most obvious on the surface of the coloured sample 5A aged and the aged sample 6T). 3.1 Visual representation 3.1 Visual representation powder of the aged sample 5A aged and the aged sample 6T). 4A fresh 4B fresh 5A fresh 6T fresh 4A aged 4B aged 5A aged 6T aged Figure 1: A visual representation of the difference between fresh and aged samples. Figure 1: A visual representation of the difference between fresh and aged samples. 3.1 Spectrometer i1 3.1 Spectrometer i1 Figure 2 shows the measurements with the i1 spectrometer. Each sample was measured at 12 different locations. Figure 2 shows the measurements with the i1 spectrometer. Each sample was measured at 12 different Each point in the graph in Figure 2 represents a measurement on the locations. Each point in the graph in Figure 2 represents a measurement on the a*, b* diagram and a*, b* L * axis. The aged sam diagram and L * -ples (4A and 4B) are less blue-coloured (the values on the axis. The aged samples (4A and 4B) are less blue-coloured (the values on the b* axis are higher) than the fresh samples (the values b* axis are higher ) th an on the the fresh samples (the values on the b* axis are lower). A greater difference can be observed in sample 4B (the values on the b* axis are lower ). A greater difference can be observed in sample b* axis decrease visibly with ageing). For sample 4A, ageing has no significant influence on the colouration (the values on the 4B (the values on the b* axis decrease visibly with ageing ). For sample 4A, ageing has no significant b* axis do not decrease significantly with ageing). The brightness does not differ significantly between the fresh and influence on the colouration (the values on the b* axis do not decrease significantly with ageing ). The aged samples. The exception is sample 4A fresh, which has slightly higher values (which corresponds to the brightness does not differ significantly between the fresh and aged samples. The exception is sample higher values on the 4A fresh, which has slightly higher values (which corresponds to the higher values on the b* axis). b* axis). Figure 2: Figure 2: Measurement results of samples 4A fresh, 4A aged, 4B fresh and 4B aged with the i1 Measurement results of samples 4A fresh, 4A aged, 4B fresh and 4B aged with the i1 spectrometer. spectrometer. Figure 3 and Table 2 show the important electronic transitions of all base components and prepared samples. We 3.2 UV-VIS spectra Figure 3 and Table 3.2 UV-VIS spectra look at the changes in the electronic transitions in CVL. The electronic transitions in CVL indicate the formation of 2 show the important electronic transitions of all base components and prepared a coloured complex. CVL in the closed lactone ring form has an electronic transition at 410 nm (3.0 eV), and in the samples. We look at the changes in the electronic transitions in CVL. The electronic transitions in CVL coloured state (when the lactone ring is open, we consider 4A, 4B, 5A as fresh) the electronic transition is shifted to 425 nm (2.9 eV). In the fresh sample 6T, we observe that the electronic transition is not significantly shifted (it d 3 555 29–30 May 2025, Ljubljana, Slovenia shifts by 5 nm), which means that only a small part of the CVL rings in the sample is open. This is also evident from the colour of fresh sample 6T, which is much brighter than fresh sample 5A (see Figure 1 and compare fresh sample 5A and fresh sample 6T). Both aged samples (5A and 6T) have the same electronic transition as CVL in the closed lactone ring form; at 410 nm (3.0 eV), which is consistent with the colour actually having faded. The colour change is also visible to the naked eye (see Figure 1, aged and fresh samples 5A and 6T). a b c d Figure 3: UV-VIS spectra of the measured samples: a – CVL, B4HB, OD; b – CVL 4A fresh, 4B fresh; c – 5A fresh, 6T fresh; d – CVL, 5A aged, 6T aged. Table 2: The most important electronic transitions of the samples. Sample λ [nm] E [eV] CVL 410 3,03 B4HB 300 4,13 OD / / 4A, 4B, 5A fresh 425 2,92 6T fresh 415 2,99 5A, 6T aged 410 3,03 3.3 FTIR spectra Hydrogen bonds are the most important bonds formed between alcohol molecules (e.g. in OD) (Colthup, 1990). This manifests itself in the form of stretching vibrations, in-plane and out-of-plane bending vibrations of the OH group. OD exhibit a very broad, strong absorption at 3302 cm-1, which is due to the stretching of the O-H bond. The vibration of the O-H group at 3375 cm-1 is also observed in the B4HB spectrum, but this vibration is not present in the CVL spectrum. A strong C-H stretching vibration at 2917 cm-1 and a C-O stretching vibration at 1063 cm-1 are also observed in the OD spectrum. The most important vibrations in B4HB are the stretching vibration of the car-bonyl group O-C=O at 1682 cm-1 and the C-O-C stretching vibration at 1272 cm-1. The most important vibrations in 556 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia CVL are characteristic of the lactone ring. The spectrum shows the stretching vibration of the carbonyl group C=O at 1740 cm-1. The stretching vibration of the C-C bond at 1608 cm-1 and the vibration of the aromatic ring (C=C) the lactone ring. The spectrum shows the stretching vibration of the carbonyl group C=O at 1740 cm-1 . at 1511 cm-1 can also be recognised. Both vibrations are also observed in the B4HB spectrum. Therefore, these The stretching vibration of the C-C bond at 1608 cm-1 and the vibration of the aromatic ring (C=C) at vibrations cannot be used to analyse the TC phenomena in the CVL and B4HB composite. 1511 cm-1 can also be recognised. Both vibrations are also observed in the B4HB spectrum. Therefore, Figures 4a and 4b show the spectra of samples 4A and 4B (fresh and aged). It can be seen that the stretching these vibrations cannot be used to analyse the TC phenomena in the CVL and B4HB composite. vibration of the carbonyl group C=O at 1740 cm-1 is only weakly pronounced. It can also be seen that the spectra Figures 4a and 4b show the spectra of samples 4A and 4B (fresh and aged). It can be seen that the change after one month. Figures 4c and 4d show the spectra of samples 5A and 6T (fresh and aged). It can be seen stretching vibration of the carbonyl group C=O at 1740 cm-1 is only weakly pronounced. It can also be that the stretching vibration of the carbonyl group C=O at 1740 cm-1 is clearly pronounced. It can also be seen that seen that the spectra change after one month. Figures 4c and 4 d show the spectra of samples 5A and the spectra have not changed after one month. 6T (fresh and aged). It can be seen that the stretching vibration of the carbonyl group C=O at 1740 cm-1 is clearly pronounced. It can also be seen that the spectra have not changed after one month. a b c d Figure 4: Figure 4: FTIR spectra of the measured samples: a – 4A fresh (pink) and 4A aged (turquoise), b – 4B FTIR spectra of the measured samples: a – 4A fresh (pink) and 4A aged (turquoise), b – 4B fresh (red) and 4B aged fresh (red) and 4B aged (blue) , c – 5A fresh (yellow) and 5A aged (grey) , d – 6T fresh (red) and 6T (blue), c – 5A fresh (yellow) and 5A aged (grey), d – 6T fresh (red) and 6T aged (black). aged (black) . Ternary TC composite with a mixture of OD+B4HB+CVL and binary TC composite with a mixture of B4HB+CVL 4. CONCLUSIONS Ternary TC composite with a mixture of OD+B4HB+CVL and binary TC composite with a mixture of 4. CONCLUSIONS were prepared. Fresh and aged samples were analysed by UV-Vis and FTIR spectroscopy as well as by co-lour analysis in CIELAB colour space. All samples measured had negative values on the B4HB+CVL were prepared. Fresh and aged samples were analysed by UV-Vis and FTIR spectroscopy a* and b* axes, which represent the blue-green colour. as well as by colour analysis in CIELAB colour space. All samples measured had negative values on The aged samples are less blue-coloured than the fresh samples. The UV-VIS spectrometer was used to determine the changes in the electronic transitions of the base components based on the a* and b* axes, which represent the blue-green colour. The aged samples are less blue-coloured 5557 29–30 May 2025, Ljubljana, Slovenia the measured transmittance values. The focus was on the change in the electronic transitions of CVL, as these indicate the formation of a colour complex. In all freshly prepared samples, the electronic transition of CVL in the composite shifted in comparison to the transition of pure CVL, which means that the lactone ring is open (coloured state). In aged samples of the binary TC composite (5A aged, 6T aged), the change in the electronic transition of CVL compared to pure CVL is small or does not occur at all. This means that most lactone rings are closed. This is consistent with visual observation; the aged samples fade/discolour with time. The FTIR analysis focussed on the valence vibration of the carbonyl group C=O at 1740 cm-1, which is characteristic of the open lactone ring and is the most important vibration in the CVL spectrum. The spectra show that the vibration of the carbonyl group is clearly expressed in the binary TC composite and that the spectra have not changed after one month. In the ter-nary TC composite, on the other hand, the spectra change after one month and the vibration of the carbonyl group is only weakly expressed. These preliminary results show that the effect can be measured using UV-VIS and FTIR spectroscopy. To be sure when protonation or deprotonation occurs as a function of time, further UV-VIS and FTIR spectra are required at different ratios of the components and at different time intervals. Future work should focus on the investigating different ratios of components in TC composites and longer time intervals of ageing. 5. REFERENCES Colthup, N., Daly, L., & Wiberley, S. (1990). Introduction to infrared and raman spectroscopy (3 ed.). San Diego: Academic press. Friškovec, M., Kulčar, R. & Klanjšek Gunde, M. (2013). Light fastness and high-temperature stability of thermochromic printing ink. Coloration Technology, 129(3), 214–222. doi:10.1111/cote.12020 Hajzeri, M., Bašnec, K., Bele, M. & Klanjšek Gunde, M. (2015). Influence of developer on structural, optical and thermal properties of a benzofluoran-based thermochromic composite. Dyes and Pigments(113), 754–762. doi:10.1016/j.dyepig.2014.10.014 Seeboth, A. & Lötzsch, D. (2008). Thermochromic Phenomena in Polymers. Shawbury: Smithers Rapra Technology Limited. White, M. & LeBlanc, M. (1999). Thermochromism in Commercial Products. Journal of Chemical Education, 76(9), 1201-1205. doi:10.1021/ ED076P1201 ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-authors: Katarina Jenko Marta Klanjšek Gunde Hajdrihova 19 Hajdrihova 19 1000 Ljubljana, Slovenia Mysteria Colorum – MyCol d.o.o. Mysteria Colorum – MyCol d.o.o. 1000 Ljubljana, Slovenia marta@mycol.si katarina@mycol.si Ondrej Panák Mysteria Colorum – MyCol d.o.o. Hajdrihova 19 1000 Ljubljana, Slovenia ondrej@mycol.si Raša Urbas University of Ljubljana Faculty of Natural Sciences and Engineering Aškerčeva 12 1000 Ljubljana, Slovenia rasa.urbas@ntf.uni-lj.si 558 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION THE INFLUENCE OF THE METALLIC SUBSTRATE‘S EMBOSSING PROCESS AND THE POSSIBILITY OF PRINTING WHITE ELECTROINK Igor Majnarić1, Meri Huljev1, Stanko Bauk2 and Filip Macan1 1University of Zagreb, Faculty of Graphic Arts, Croatia 2Sato. d.o.o., Slovenia Abstract: Printing white ink on silver metalized substrates is a general trend in label printing and cardboard packaging production. In the creation of smooth silver metalized substrates, printing companies can create va-rious embossed structures, reducing metallic reflection while creating additional content. In this paper, embos-sing pre-processing was performed (with the Pantec Rhino S510 in-line printing unit installed in the OMET xFlex printing hybrid machine). This process generated two structures of printing substrate: factory gloss and grainy embossed foil (Vacuum Metal Silver-Lux Ultra WS). On printing the white mask, an HP Indigo WS 6800 elec-trophotographic printing machine was used. The experiment was carried out with different thicknesses of white ElectroInk ink (one, two, and three layers of white). The analysis of the new surface roughness was made with the MarSurf PS10 device and the determination of the hardness of the white coating was made with Elcometer 3092 device. Results show that the white ink adhesion is better with the factory metalized substrates (unembossed), while increased applications of white Elektronik ink will not change roughness notably. The optimal amount of white ElectroInk that could be used to print additional CMYK inks would be made with two layers. Keywords: white ElectroInk, embossing of metalized substrates, surface roughness, coating hardness 1. INTRODUCTION Along with the dominant plastic and cardboard packaging (currently around 40% flexible and rigid plastic pac-kaging and 35% shipping, food, and retail paper and cardboard packaging are printed), metal packaging is the third with a share of 10 - 15%. In the category of metal packaging, we primarily include metal boxes and cans for beverages, food, or cosmetics. However, in this category, we include labels and closures whose primary function is labeling and closure. Thus, with the application of varnishes and printing inks, the visual effect of the metalized surface will be maintained. Before printing, metalized surfaces can be treated. Mechanical and chemical proces-ses are used. (Gotch, 2023.) Metals that are successfully used are: Pewter (soft alloy with a low melting point and is easy to emboss work), Gold (excellent elasticity and flexibility and one of the most malleable metals for luxury goods), Silver (flexible, can be pressed into fragile silver foil, and can form complex patterns and designs), Stainless steel (high strength, ex-cellent corrosion resistance, and can withstand more significant pressure and impact, and is not easily deformed, Aluminum alloy (good formability and lightweight characteristics), Copper (warm hues and malleability, suitable for metal embossing). Depending on the final application, the aluminum surface can be pre-treated using engraving (jewelry), etching (design complex patterns), and embossing (packaging, tools, and implements). Using gravers, rotary tools, and laser engravers, fine lines and depth are achieved on aluminum. This is also the main charac-teristic of engraving processing. Larger flat hollows and complex textures on aluminum are obtained using the etching methods tools, etching needles (selective application of acid-resistant materials), and etching acids. To get a clear three-dimensional effect of embossing, tools that can be used are Stylus, embossing presses, and rolling mills. Metal embossing is a technique in processing metal packaging and producing labels and closures. In doing so, two printing forms (male and female elements) are used, which, through their joint action, create complex 559 29–30 May 2025, Ljubljana, Slovenia raised or recessed patterns, images, or text on metal surfaces. This technique primarily increases the aesthetic appearance of metal products and improves their functionality in various applications. (hlc-metalparts, 2025) The preliminary research aims of this paper are to investigate in more detail the surface of the embossed and non-embossed self-adhesive metalized substrate before it is further processed in the CMYK and CMYK +W digital printing processes (Inkjet and EP). 2. THEORETICAL PART 2.1 Aluminum-Metalized Self-Adhesive Material Aluminum-coated self-adhesive material is the predominant choice for creating labels with a metallic sheen. This type of material is primarily designed for beer labels, labels for sparkling wines and other wines, as well as luxury labels and declarations for cosmetic products and perfumes. The construction of aluminized label mate-rial comprises five layers: a surface metalized layer, a specially treated intermediate layer, a layer of permanent acrylic water-based adhesive, a silicone layer for facilitating the easy removal of the adhesive from the liner, and a backing liner made of supercalendered white paper (Fedrigoni VMS, 2025). Printing on this material is conducted exclusively on the top metalized surface, utilizing printing techniques compatible with solvent and UV-curing inks. Digital printing particularly employs ElectroInk and UV LED-cured inkjet inks (Landa, 1988). Designs typically fea-ture stark contrasts in white and black inks; however, metallic hues of cyan, magenta, and yellow can be produced through the application of other process inks (Pierce, 1999). 2.2 Aluminum Metallized Layer For reasons of practicality and reduced production costs, the outer layer is not composed of coated aluminum. Instead, a 12 µm thick polymer base, enhanced with a vacuum metalized aluminum layer measuring 40 nm, is utilized due to its significantly more favorable pricing. The vacuum metallization of materials involves a process known as Physical Vapor Deposition (PVD), where metal is deposited through vaporization at a rate of 10 m/s. This technique enables the production of coatings via the thermal evaporation of metals, allowing for application on various substrates. PVD is also employed in the creation of diverse graphic products, including the polymer rolls commonly used in the packaging industry (Rong, 2008; Forgacs, 2013). A crucial aspect of the PVD process is the thermal evaporation of the metal. The control of the vaporization process relies on several factors: the heat source applied, the characteristics of the material being evaporated (the evaporator), the boat or crucible from which it is released, the deposition method, the distribution from the evaporator, and the pressure or environment in which the process occurs. Figure 1 illustrates a schematic representation of the PVD process (Yam, 2009). Figure 1: Schematic view of the aluminum oxide deposition process: a) reactive aluminum evaporation; b) Vacuum coating on roll materials on smaller machines. To controllably deposit aluminum vapor onto plastic film substrates, additional aluminum wire and rod must be pla-ced in a hot boat or crucible. Heat sources for melting include resistance, induction, and electron beam heaters. Optionally, a high-frequency electron beam can be directed onto the aluminum wire to enhance productivity. This radiation is generated by a precisely positioned electro-beam gun. 560 29–30 May 2025, Ljubljana, Slovenia The liberated aluminum vapors then pass through oxygen inlet nozzles and enter a controlled zone influenced by two plasma sources. To ensure proper adhesion to the plastic film, the aluminum vapors must be cooled. Con-sequently, the pressure cylinder is continuously cooled. In the event of a potential stoppage in the roll transport, a shutter is activated to close off the distribution of aluminum vapors. In vacuum metallizers, various factors, such as the selected geometry and the distance between the vaporizer source and the roll substrate, as well as the activation or deactivation of the cooling roller—which serves as an adjusting component for managing substrate temperature and coating speed—impact the properties of the final coating. In the case of a double-sided vacuum application, the system includes two cooled pressure cylinders. This enables one side of the substrate roll to be evaporated before it is turned over for evaporation on the other side. (Yam, 2009) Heating caused by the resistance of electric current utilizes various reflective metals as heat sources. An effecti-ve resistance heating source consists of an electrical conductor with high electrical resistance, enabling it to reach the evaporation temperature with reasonable voltage levels. Refractory metals, such as tungsten, molybdenum, and tantalum, are also employed (these materials are chemically inert and possess higher melting points along with lower vapor pressures than aluminum), which is used as the evaporator. In practice, the most common con-figuration involves knitted refractory wires. Tantalum is particularly useful for depositing more complex shapes. Additionally, boron nitride, along with aluminum nitride, is utilized to shape materials into desired forms. Three-part boats made from boron nitride, aluminum nitride, and titanium diboride are also utilized. Typically, eleven such vessels are powered by a voltage of 20 V, which can be easily programmed to prevent rupture due to sudden current surges entering the cold boat or crucible. Induction heating represents another type of heat source that can be utilized, although it is seldom used today due to challenges in control and diminishing economic viability. Nevertheless, it offers several advantages, including a consistent evaporation rate, stable maintenance of coating thickness uniformity, the capacity to use multiple evaporation sources, prevention of uncontrolled spraying, automatic regulation of the evaporation rate, ease of control, high aluminum purity, and extended boat lifespan. Additionally, it can refine more than 40 different types of metals. One of the key advantages of electron beam heating is that it has no upper-temperature limit, enabling the evapo-ration of nearly any material. Currently, electron beam guns are utilized in metallization systems, available in both horizontal and vertical orientations. Horizontal electron beam sources create a beam that is reflected at 270° and directed onto a production roll with a width of 1000 mm. This design helps prevent vapor contamination and en-sures a precise focus of the electron beam. In these systems, magnets are used to deflect the beam, allowing for optimal coverage of the boat that holds the vaporizer. Typical axial electron beam sources can generate a beam that, with proper deflection, can effectively cover the entire boat containing the vaporizer in nearly any configura-tion desired. When utilizing electron beam heating, it is crucial to ensure that secondary electrons do not strike the surrounding polymer material, as their thermal exposure can cause damage or destruction. While this heating method may be more expensive, it is also relatively straightforward to implement. The leading manufacturer of electron beam sources is VON ARDENNE GmbH, a German company that produces various configurations of these devices. Their products offer a maximum beam power ranging from 150 to 800 kW, with a turbomolecular pump capacity of 300 to 500 l/s in the cathode chamber, and X-ray leakage of less than 1 µSv/h (VON ARDENNE, 2025). There are approximately 500 different types of metallizers available globally. These metalizing devices, when paired with roller coating machines, are capable of performing a diverse array of functions that extend beyond the requirements of the packaging industry. Additionally, this technology serves as the leading producer of alumi-num-coated polymer films. (Lenk, et al. 1997) The metalizing coating industry features a variety of in-line and offline configurations for roller coating machines. Regardless of the specific setup, the production process comprises four key steps: a) pre-coating (air removal), b) leading coating, c) aeration (air injection), and d) secondary coating. To enhance productivity, double-sided air-to-air coating machines have been introduced. These machines significantly improve equipment cost-efficiency while increasing production volume by 50%. This type of machinery is applicable in the packaging industry as well as in the coating of metal strips. (Johnson et al., 1998) 561 29–30 May 2025, Ljubljana, Slovenia In addition to manufacturing embossing foils, the metallization process can also be utilized in creating gold-plated and silver-plated textiles such as bags, ties, curtains, towels, socks, scarves, slippers, tablecloths, lace, and stage costumes. Furthermore, the technique is applicable to ornamental items, including interior decorations, cosmetic packaging, christmas tree ornaments, nameplates, and baubles. It can also be employed in building materials like umbrellas, blinds, interior walls, and thermal insulation, as well as in the production of reflective metalized substra-tes used in traffic signs, license plates, mirrors, and capacitors. 3. EXPERIMENTAL PART For the experiment, a printing form was made containing a white media wedge of 10 x 12 cm with patches ran-ging from 10 to 100% TV (10% TV step). The form was created in Adobe Illustrator version 2022 and saved in PDF X4 (format uploaded into the seven-color HP Indigo WS 6800 EP machine). For printing on the HP Indigo WS 6800, the special ElectroInk white color was activated. The printing substrate was a five-layer metalized foil Vacuum Metal Silver-Lux Ultra ws/SH6020 plus/WG80 produced by Fedrigoni company (table 1). In the RIP Esko HP SmartStream RIP Server (HP Indigo WS 6800), three variations of the white samples were made (sample 1 printed with one coat S1, simple with two coats S2, and simple for three coats S3). (HP Indigo, 2024) Table 1: Characteristics of Self-Adhesive Film Vacuum Metal Silver-Lux Ultra WS /SH6020 plus/WG80 Front Label Layer Reference name VACUUM METAL SILVER LUX ULTRA WS Opće karakteristike Metallised silver paper with high vacuum aluminium particles with high gloss grade and with an ULTRA WS treatment Grammage ISO 536 (g/ 103 m 2 ) Thickness ISO 534 (µm) 85 Adhesive layer Reference name SH6020 PLUS Permanent acrylic water based adhesive. Good adhesion to wet surfaces General characteristics at low temperatures. Especially designed for glass containers, with excel- lent resistance to immersion in water/ice. Tack (N) glass FTM-9 >12 Cohesion (h) 1kg FTM-8 >2 Labelling temperature >5°C (ºC) Usage temperature (ºC) -10°C/+75°C Support layer Reference name WG80 General characteristics Supercalendered glassine paper, white. Grammage ISO 526 (g/ 78 m 2 ) Thickness ISO 534 (µm) 67 Tensile strength ISO MD(KN/m) > 6,8 1924 MD/CD (KN/m) CD(KN/m) > 3,0 The first part of the experiment was based on direct white printing onto the foil’s top metalized layer. In contrast, in the second part of the experiment, the metalized foil was first embossed on a Pantec Rhino S 510 unit (patterns were embossed with a mass of 80 tons to create a relief structure on the foil). (RHINO 510 S, 2025.) After that, a structured metalized aluminum self-adhesive foil was developed and re-printed with white ElectroInk (samples printed with one layer S4, samples with two layers S5, and samples with three layers S6). All the resulting sam- 562 29–30 May 2025, Ljubljana, Slovenia ples of white ElectroInk ink were fixed to a 4 mm thick glass surface using a FINAT roller weighing (1 kg and a hardness of 70° Sh). To determine the mechanical properties of the printed white ElectroInk layers, a MarSurf PS10 coating profile measuring device (Ra, Rp, and Rz profile) and an Elcometer 3092 Sclerometer coating hardness measuring device were used. (Roughness Tester, 2024; Elcometer 3092, 2024.) The results of the achieved profiles (with-out printed white ink layers and with printed white ink layers) were shown in a profile roughness diagram using the OriginPro 8.5 program. Using this digital printing method for small editions (CMYK + CMYKW), a dual-color metallic effect can be achieved alongside standard CMYK color reproduction on a white base. The chronological course of the experiment is shown in Figure 2. Figure 2: Schematic representation of the experiment. 4. RESULTS AND DISCUSSION Three key parameters define surface roughness: Ra, which represents the arithmetic mean value of the profile; Rp, the absolute height of the profile irregularities; and Rz, which indicates the heights of the ten highest irregular-ities. Specifically, Rz is the sum of the mean height derived from the five tallest peaks and the five deepest valleys of the profile in relation to Ra and Rp, highlighting the extremes of surface roughness. Figures 3, 4, and 5 present graphical representations of the Ra, Rz, and Rp roughness parameters, as measured on white prints produced by HP Indigo, using both a smooth and an embossed metalized surface. 563 29–30 May 2025, Ljubljana, Slovenia Figure 3: Roughness values of various white ink layers printed on the HP Indigo WS 6800 a) Ra of an original metalized substrate; b) Ra of an embossed metalized substrate. Figure 3a displays a histogram illustrating the changes in the roughness of a factory metalized surface printed using an HP Indigo printing press. All results are derived from 10 measurements, with only the calculated mean values presented. The lowest roughness was observed on the original printing substrate (without printed white ink), recording a value of Ra = 0,6 µm. With the application of one layer of ElectroInk white ink, the surface rough- ness demonstrated a slight increase, with a change of ΔRa = 0,02 compared to the original substrate. sub._S1 The standard deviation ranged from 0,44 µm to 0,84 µm, indicating a rougher surface. The roughness increased further with two coats of ElectroInk white, resulting in a change of ΔRa = 0,04, with measurements fluctuating S1_S2 between 0,5 µm and 0,73 µm. After applying three layers of ElectroInk white ink, the roughness slightly increased compared to the two-layer application (ΔRa = 0,07 µm), with measurement results ranging from 0,55 µm to S2_S3 0,82 µm. In summary, additional applications of HP Indigo white ink lead to a minor increase in the roughness of the printed white surface. Figure 3b presents a histogram illustrating the roughness parameter Ra of three different layers of white Elec-troInk ink printed on an embossed metalized substrate. The unprinted embossed substrate exhibits a high rough- ness (Ra = 13,04 µm), accompanied by a substantial statistical error in the measurement (ranging from 8,90 emboss µm to 18,90 µm). The histogram clearly indicates that the application of a single layer of white ink reduces the roughness, suggesting that the ink has partially filled the depressions present on the embossed surface. Spe- cifically, with one layer of ElectroInk white, the roughness decreased by ΔRa = 1,53 µm compared to the emboss_S4 clean substrate, while a significant statistical deviation persists (between 7,59 µm and 21,33 µm), highlighting the inhomogeneity of the resulting surface. When two coats of ElectroInk are applied, the fluctuations in the roughness measurements diminish, indicating a more uniform application of the pasty electrophotographic white ink. The difference in roughness between the first and second layers of white ElektroInk is minimal, with an insignificant ΔRa = 0,01 µm. Furthermore, upon S4_S5 applying a third layer of white ElectroInk, there is a slight increase in roughness by ΔRa = 0,17 µm. The results S4_S5 from a more extensive set of measurements show the least variation, ranging between 6,70 µm and 16,74 µm. These findings suggest that increasing the application of ElectroInk does not significantly alter roughness, indicat-ing that it does not further decrease despite the underlying grainy embossed surface. 564 29–30 May 2025, Ljubljana, Slovenia Figure 4: Roughness values of different layers of white colors printed on HP Indigo WS 6800 a) Rz of the original metalized substrate; b) Rz values of the embossed metalized substrate. Figure 4a shows the histogram of Rz roughness parameters for three different layers of white Electroink. It is evident from the obtained measurement values that the deviations are more significant compared to the Ra measurements. It is also apparent that with the increase in ElectroInk application, there is a linear increase in the parameter Rz. The lowest value was measured with the original substrate and is Rz 2,93 µm, with a standard sub = deviation from 2,41 µm to 3,92 µm. By applying one layer of white ElectroInk, the roughness increases compared to the original substrate (ΔRz = 0,49 µm), and the results of 10 measurements oscillate between 2,73 µm sub_S1 and 4,06 µm. With two coats of white ElectroInk, the Rz parameter increases compared to the original substrate. This difference amounts to ΔRz = 0,85 µm. However, the measurement results oscillate less and range from S1_S2 3,16 µm to 4,33 µm. Compared to the original substrate with three layers of white ElectroInk, the Rz parameter increases the most. This difference compared to the printing substrate amounts to ΔRz = 1,44 µm. sub_S3 At the same time, the obtained roughness results oscillate between 3,65 µm and 4,95 µm. With the application of three layers of ElectroInk, large oscillations occur in the results, and the printed white surface has a significant roughness deviation. Figure 4b presents a histogram detailing the Rz roughness parameters of various printed white colors on HP Indigo applied to an aluminized embossed metalized substrate. The measurements reveal that the unprinted em-bossed substrate (lacking a layer of white ink) exhibits the highest Rz value, which diminishes with the application of ElectroInk. Specifically, the pure embossed substrate has an Rz value of 59,92, with measured values ranging from 40,73 µm to 85,66 µm. The application of a single layer of white ElectroInk reduces both the roughness and the Rz parameter, decreasing by ΔRz = 6,76 µm compared to the unprinted substrate. However, this single embos_S4 ink layer introduces significant variability in the measurements, oscillating between 36,58 µm and 84,13 µm. In contrast, after applying two layers of white ElectroInk, the roughness decreases slightly more (ΔRz = 0,64 S4_S5 µm), but the measurement results exhibit smaller oscillations, ranging from 44,23 µm to 68,21 µm. This indicates that two layers of printed white ElectroInk produce the most uniform surface. However, when three layers of white ElectroInk are applied, the roughness results show an increase compared to the two-layer application (ΔRzS5_S6 = 4,14 µm), alongside heightened measurement oscillations ranging from 36,38 µm to 75,86 µm. The addition of color to an already applied layer does not enhance the uniformity of the printed white surface; therefore, it appears that overprinting should be limited to a maximum of two layers of white ElectroInk for optimal results. 565 29–30 May 2025, Ljubljana, Slovenia Figure 5: Roughness values of various layers of white ink printed on the HP Indigo WS 6800: a) Rp of the original metalized substrate; b) Rp value of the embossed metalized substrate. Figure 5 presents a histogram of the roughness parameter Rp for the different printed layers of white ink. Nota-bly, using the HP Indigo leads to an increase in the Rp parameter when compared to the original substrate. The Rp roughness of the original metalized substrate is measured at R = 1,51 µm, exhibiting fluctuations within the sub range of 1,3 µm to 2,15 µm. In contrast to the unprinted substrate, the maximum depth of the profile rises with the initial application of ElectroInk, resulting in ΔRp = 0,20 µm. The measurements in this case vary between sub_S1 1,36 µm and 2,13 µm. With the addition of a second layer of ElectroInk, there’s a further increase in the Rp rough- ness; specifically, compared to the first layer of white ink, an increase of ΔRp = 0,18 µm is observed. The S1_S2 standard deviation for these measurements fluctuates between 1,62 µm and 2,15 µm, indicating that this surface was printed most uniformly, exhibiting the smallest variations in results. The highest Rp roughness was recorded after applying three layers of ElectroInk white ink, which increased by ΔRp = 0,27 µm in comparison to the S2_S3 two-layer application. This white print also demonstrated the largest measurement oscillations, ranging from 1,72 µm to 2,86 µm. The Rp parameters of extreme roughness observed during the printing of various layers of white ElectroInk on an embossed metalized substrate are illustrated in Figure 5b. The histogram indicates that increasing the number of white color layers results in a slight reduction in profile depth. An exception occurs with prints that utilize a layer of pasty electrophotographic ink. The unprinted embossed substrate exhibits the maximum profile value of Rp = 27,43 µm, with measurements embos ranging from 14,13 µm to 36,80 µm. When a single layer of ElectroInk is applied, the profile depth decreases, measuring (ΔRp = 0,64 µm) relative to the original substrate. Samples with this configuration also show the embos_S4 greatest variability in measurements, spanning from 16,07 µm to 48,38 µm. In comparison, applying two layers of ElectroInk white results in a further reduction of the maximum profile depth by ΔRp = 1,97 µm. Notably, with S4_S5 this two-layer print, even the smallest oscillations in measurements are observed, ranging from 17,39 µm to 27,43 µm. When a third and final layer is added, the maximum depth shows a slight increase of ΔRp = 3,51 µm, ac-S5_S6 companied by a narrower range of measurements (from 15,44 µm to 39,64 µm). This indicates that the third layer of ElectroInk does not effectively penetrate the embossed substrate but instead adheres to the surface areas. In addition to the profile achieved, an essential parameter is the hardness of the coating. According to the ISO 4586-2 standard, the hardness of coatings and inks can be assessed using the Elcometer 3092 Sclerometer. The results of these measurements (table 2) are evaluated visually, with four possible descriptive ratings: 1 ink does not peel off; 2 partial ink peeling; 3 visible ink peeling; and 4 tearing of the imprint. 566 29–30 May 2025, Ljubljana, Slovenia When applying a single layer of white ElectroInk on a factory-finished metalized surface, minimal damage occurs under low forces. The initial traces on the print become evident at a force of 7 N while tearing is observed at a force of 10 N. Therefore, it can be concluded that one layer of ink possesses a hardness rating of 7 N, corresponding to a hardness rating of 3. Both tested directions of applying pressure with the stylus yield no significant differences. With two layers of white ElectroInk, a noticeable difference was observed depending on the direction of the stylus drawing. When two applications were made in the direction of printing (MD), a force of 0,5 N resulted in a visible line, indicating partial removal of the ink layer, while a force of 1 N led to significant ink removal. Increasing the force to 2 N caused the sample to tear. From these measurements, it can be concluded that the hardness of the two layers of white is 1 N, corresponding to a rating of 3. Conversely, when two layers of white were applied in the opposite direction of printing (CD), the ink remained intact even under a force of 20 N, resulting in a rating of 1. Table 2: The hardness of different layers of white ink produced on the HP Indigo 6800 WS Printed Elektroink white inks on an HP Indigo 6800 WS press 1 layer 1 layer Machine emboss emboss emboss Cross direction direction 2layer 1 layer 2 layer 3 layer 0.5 N 1 2 1 1 1 1 1 1 N 1 3 1 1 1 1 1 2 N 1 4 1 1 1 1 1 3 N 1 / 1 3 1 1 1 4 N 1 / 1 / 1 1 1 5 N 1 / 1 / 1 1 1 7 N 3 / 1 / 1 1 1 10 N 4 / 1 / 1 1 1 14 N / / 1 / 1 1 1 20 N / / 1 / 1 2 2 Ratings 1 ink does not peel off; 2 partial ink peeling; 3 visible ink peeling; 4 tearing imprint. The application of three layers of white ElectroInk results in visible ink removal when a force exceeding 3 N is applied. This force also determines the final hardness of the layer. Based on these tests, it is recommended to apply the ink in one or two layers, while carefully considering the direction of deformation (damage). In embossed samples produced through printing on the HP Indigo, an improved hardness of the white layer was observed. When printed with a single layer of ElectroInk white, the ink demonstrated stylus resistance against a force of up to 20 N, with no damage sustained to the ink layer. However, when multiple applications were utilized (two or three layers of white), applying a force of 20 N resulted in only partial removal of the ink layer, indicating a slight decrease in hardness. 567 29–30 May 2025, Ljubljana, Slovenia 5. CONCLUSION In evaluating the roughness of white prints produced on HP Indigo, the differences observed were minimal. The deviation for white prints on a smooth surface was ΔRa=0,11, while for an embossed surface, it was ΔRa=0,18. The analysis indicates that the optimal print quality for white ink on HP Indigo machines was achieved with two layers of white ink. Additionally, the printing direction has an impact on the hardness of the resulting white layer; specifically, the cross-direction exhibits better performance than the machine direction, with the coating demon-strating resistance to a force of 20 N. It is noteworthy that altering the surface structure through the embossing process leads to variations in tone, particularly at higher surface coverage levels. In halftone printing, color changes are more pronounced, whereas full-tone variations remain minimal. In the factory-processed metalized sample featuring two layers of white ElectroInk, a noticeable difference in hardness and varying printing directions was observed. In contrast, all other tested samples exhibited uniform hardness in the ink layer across both media directions. The highest level of hardness was recorded in the em-bossed sample with a single layer of white ink. Samples with two and three layers were only slightly behind in terms of coating hardness. 6. REFERENCES Elcometer 3092, https://downloads.elcometer.com/PDFs/Datasheets/English/3092.pdf, Elcometer 3092, 9.2.2024.” (last accessed on 9. 2. 2024). Fedrigoni Vacuum Metal Silver, http://en.arconvert.it/products/WNE0368-es/print/?tipus%5B0%5D=, Vacuum Metal Silver LUX Ultra WS / SH6020 PLUS / WG80, (last accessed on 9. 2. 2024). Forgacs P., (2013.) Theory of Ink Transfer in HP-Indigo Digital Press Machines. NIP29: The 29th International Conference on Digital Printing Technologies and Digital Fabrication 2013. Seattle, Society for Imaging Science and Technology, p.429 Gotch, E., The Future of Paper vs Plastic Packaging Markets to 2028, Smithers, Information Division, Olympus House, Cleeve Road, Leatherhead, KT22 7SA, UK, (2023) hlc-metalparts, What Is Metal Embossing? Detailed Comprehensive Guide, https://www.hlc-metalparts.com/news/what-is-metal-embossing-77240679.html (last accessed on 23. 01. 2025). 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Rong X., (2008.) G7 Method for Indigo Press Calibration and Proofing, The 24th International Conference on Digital Printing Technologies and Digital Fabrication, Pittsburgh, Society for Imaging Science and Technology, p. 603 Roughness Tester, https://5.imimg.com/data5/AD/JL/MY-41879825/portable-roughness-tester.pdf, Portable Roughness Tester, (last accessed on 9. 2. 2024). VON ARDENNE GmbH, EH800V electron beam guns https://vonardenne.cn/fileadmin/ user_upload/brochures/COMP_Ebeam/Ebeam_ COMP_eng.pdf (last accessed on 27. 01. 2025). Yam K. L., (2009.) Encyclopedia of Packaging technology (3. edition), p. 741.-750. John Wiley & Sons Inc. ISBN: 978-0-470-09704-6, Publisher. 568 29–30 May 2025, Ljubljana, Slovenia ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Igor Majnarić Meri Huljev Faculty of Graphic Arts Faculty of Graphic Arts Getaldićeva 2 Department of Printing University of Zagreb University of Zagreb Getaldićeva 2, 10000, Zagreb, Croatia 10 000 Zagreb, CROATIA huljevmeri@gmail.com Stanko Bauk +385 912882029 Sato. d.o.o. igor.majnaric@grf.unizg.hr Vodovodna ulica 2 49 210 Zabok, Croatia stanko@sato.hr Filip Macan University of Zagreb Faculty of Graphic Arts Getaldićeva 2 10000, Zagreb, Croatia filip@macan.hr 569 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION INFLUENCE OF GLYCEROL CONCENTRATION ON THE WETTING PROPERTIES OF THE METHYLCELLULOSE COATING Tomislav Cigula1, Teodora Lukavski1, Marina Vukoje1, 1 Rahela Kulčar and Katarina Itrić Ivanda 1 1University of Zagreb, Faculty of Graphic Arts, Croatia Abstract: There are two main applications of coatings in graphic industry – primer on a printing substrate and an overprint coating for protection of the print or making some aesthetic feature. In this paper we focus on overprint coatings and aim to investigate wetting of the coatings prepared by mixing methylcellulose solution with glycerol applied onto different printing surfaces. For this research four coatings were prepared by altering weight ratio of glycerol in them. Measurements of the viscosity of coatings as well as contact angle on various surfaces were performed. Results of the investigation showed that adding glycerol will not significantly affect the viscosity of the methylcellulose solution and that the measured contact angles were high, with the lowest on coated paper. The glycerol amount does not significantly influence wetting, but relatively high contact angles of all samples indicate the need of wetting agents to apply them in graphic industry. Keywords: methyl cellulose, glycerol, coating, contact angle, wetting properties 1. INTRODUCTION Coating is a term which describes providing a layer of one substance on the other. In the graphic industry coatings are used in two different fields, as a primer or as an overprint varnish. The primer is set to enable a surface to have good printability, i.e. to enable proper ink transfer (Havenko et al., 2020; Morić* et al., 2019). On the other hand, overprint coating is used to enhance aesthetics of the print in terms of enhanced gloss of the surface or parts of the surface, to provide matte effect or to give protection of the ink film against mechanical or environmental deteri-oration. When applying an overprint coating there are some obstacles regarding transparency (Hébert et al., 2021) and by the fact that is applied on a homogeneous surface, i.e. clear printing substrate and/or ink film. Methyl cellulose is the simplest cellulose derivative that offers wide variety of applications (Nasatto et al., 2015). It is often used as an adhesive in paper conservation (Borges et al., 2018). As materials used in conservation should not significantly influence basic material properties, it provides good basis for the application as an overprint coating. In the terms of cardboard packaging, the coating should be flexible not to crack under bending. Glycerol is often used as a plasticizer to various biobased materials used in packaging (Khotsaeng et al., 2023; Żołek-Try-znowska & Cichy, 2018) giving the film flexibility and therefore better properties. Having in mind all above, the aim of this paper is to examine wetting of the coatings prepared by mixing methyl-cellulose solution with glycerol when applied on various printing surfaces. 2. EXPERIMENTAL For this experiment four samples of the coatings were prepared by altering amount of added glycerol. First a solution of the methylcellulose was prepared by mixing 1 g of methylcellulose powder (purchased from Talas, New YOR, USA) in 100 mL of demineralized water. The solution was mixed with magnetic stirrer at 600 rpm at room temperature (22 oC) for 30 minutes. After mixing, the solution was left to settle down for 48 hours. After settling down, methylcellulose solution was used to prepare mixtures with glycerol in weight ratios of 10, 20 and 30 % (in accordance with Table 1). 570 29–30 May 2025, Ljubljana, Slovenia After adding glycerol to methylcellulose solution samples were mixed for 10 minutes at 500 rpm and room tem-perature (22 oC). Before taking measurements, samples of coating were left to settle (some air bubbles was ob-served in solutions) for 24 hours. Table 1: Composition of prepared coatings Sample Methyl cellulose Glycerol (g) Total (g) solution (g) C0 50 0 50 C10 45 5 50 C20 40 10 50 C30 35 15 50 Measurements of the viscosity were performed to determine change of this significant property due to the compo-sition of the coating. The measurements were conducted using Anton Paar RheolabQC. The unit is temperature controlled by external water bath. The sample of a coating was placed in the unit and left conditioning for 15 min-utes to achieve defined temperature (22 oC). The test of viscosity was made by setting the shear rate of 1/200 s-1 and the value presented in results section was obtained after 10 minutes of the test procedure. For the wetting properties testing three surfaces were used, a coated cardboard (Finesse gloss, UPM), uncoat-ed cardboard (Tauro offset, Sappi) and full tone offset printed black ink (Novavit Supreme Bio, Flintgroup) on a coated cardboard. The contact angle measurements were performed by the use of Dataphysics’ OCA30 device, applying the Sessile drop method with a drop of 1 µL and utilizing Young-Laplace fitting method. The obtained contact angle value was obtained four seconds after the initial liquid-solid contact. 3. RESULTS The results of the viscosity measurements is presented in Figure 1. It can be seen that at defined shear rate (1/200 s-1) and temperature, viscosity of the coatings changed significantly only for the sample C10 (w(glycerol) = 10%). Nevertheless, it can be observed that increasing the glycerol weight ratio will lead to slight increase of the viscosity. Figure 1: Viscosity of prepared coatings Figure 2 presents results of the measured contact angles. Point in the graph represents average contact angle values and the error bars represent standard deviation. It can be observed that on coated cardboard and ink film (printed on coated cardboard) contact angle increases with the increase of the weight ratio of glycerol. On the other hand, applying coatings on the uncoated paper the contact angle will decrease. In addition, contact angles 571 29–30 May 2025, Ljubljana, Slovenia are the highest on the uncoated cardboard and the lowest on the coated cardboard (except for C30 on coated cardboard). Figure 2: Contact angle of prepared coatings on different surfaces The coating of the paper often includes various components, one of which could be polysaccharides (Li et al., 2020) leading to the better wetting with the methylcellulose coating, so adding glycerol will increase the contact angle. The smallest change of the contact angle due to the coating composition on ink film is probably conse-quence of its compact layer with no chemical interaction of coating with the dry ink film. Figure 3: Dynamic contact angle of methylcellulose coating without glycerol To determine application of a coating on the surface a bit further, dynamic contact angle of sample containing only methylcellulose was presented in Figure 3. These results are representative as all coating have similar behavior. It can be seen that on the ink film contact angle quickly stabilizes after approx. 0.5 s. The smallest change in time was obtained on the uncoated cardboard while the contact angle on coated cardboard stabilizes at 5 second with significant change from the initial contact (t = 0s). The relatively stable contact angle on the uncoated cardboard could be the consequence of the parallel mecha-nisms of surface interaction and partial absorbance of the coating on the rough surface of the substrate. 572 29–30 May 2025, Ljubljana, Slovenia 4. CONCLUSIONS The aim of this paper was to determine influence of adding glycerol to methylcellulose coating on wetting prop-erties when applied onto various printing substrates. The results of the investigation showed that adding glycerol will not significantly change coating’s viscosity. The contact angle is changing with the added glycerol, but the behaviour is more dependent on the substrate on which coating is applied. To conclude, this research has shown that adding glycerol to methylcellulose coating will not significantly influence wetting properties, but as relatively high contact angles for all investigated coating-substrate combinations indi-cates the need of wetting agents for application of these coatings in the graphic industry. 5. ACKNOWLEDGMENTS This work was carried out as part of the project IP-2022-10-3864: Improvement of Packaging Products through the Application of Environmentally Friendly Materials and Inclusive Design. 6. REFERENCES Borges, I. da S., Casimiro, M. H., Macedo, M. F., & Sequeira, S. O. (2018). Adhesives used in paper conservation: Chemical stability and fungal bioreceptivity. Journal of Cultural Heritage, 34, 1–8. https://doi.org/10.1016/j.culher.2018.03.027 Havenko, S., Khadzhynova, S., Olejnik, K., Kibirkštis, E., & Vaitasius, K. (2020). Influence of Primers on the Optical Characteristics of Ink-Jet Imprints. Mechanika, 26(4), 360–364. https://doi.org/10.5755/j01.mech.26.4.24434 Hébert, M., Dailliez, F., & Simonot, L. (2021). Why a clear coating modifies halftone color prints. Electronic Imaging, Material Appearance 2021, 1311–1318. https://www.researchgate.net/publication/349516630 Khotsaeng, N., Simchuer, W., Imsombut, T., & Srihanam, P. (2023). Effect of Glycerol Concentrations on the Characteristics of Cellulose Films from Cattail (Typha angustifolia L.) Flowers. Polymers 2023, Vol. 15, Page 4535, 15(23), 4535. https://doi.org/10.3390/ POLYM15234535 Li, Q., Wang, S., Jin, X., Huang, C., & Xiang, Z. (2020). The Application of Polysaccharides and Their Derivatives in Pigment, Barrier, and Functional Paper Coatings. Polymers 2020, Vol. 12, Page 1837, 12(8), 1837. https://doi.org/10.3390/POLYM12081837 Morić*, M., Majnarić, I., Pap, K., & Miloš, S. (2019). The influence of pre-treatment by priming on the CMY reproduction quality printed with ElectroInk. Tehnički Glasnik, 13(4), 305–310. https://doi.org/10.31803/TG-20191029125530 Nasatto, P. L., Pignon, F., Silveira, J. L. M., Duarte, M. E. R., Noseda, M. D., & Rinaudo, M. (2015). Methylcellulose, a Cellulose Derivative with Original Physical Properties and Extended Applications. Polymers 2015, Vol. 7, Pages 777-803, 7(5), 777–803. https://doi.org/10.3390/ POLYM7050777 Żołek-Tryznowska, Z., & Cichy, Ł. (2018). Glycerol Derivatives As a Modern Plasticizers for Starch Films. 217–222. https://doi.org/10.24867/ grid-2018-p27 ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Rahela Kulčar Tomislav Cigula Teodora Lukavski Department for graphic materials and printing forms University of Zagreb Department for graphic materials University of Zagreb Faculty of Graphic Arts and printing forms Faculty of Graphic Arts Getaldićeva 2 University of Zagreb Getaldićeva 2 10000 Zagreb, Croatia Faculty of Graphic Arts 10000 Zagreb, Croatia teodora.lukavski@grf.unizg.hr +385 1 2371 080 / 225 Getaldićeva 2 rahela.kulcar@grf.unizg.hr 10000 Zagreb, Croatia Marina Vukoje tomislav.cigula@grf.unizg.hr University of Zagreb Department of fundamental and general knowledge Faculty of Graphic Arts University of Zagreb Getaldićeva 2 +385 1 2371 080 / 248 and general knowledge Katarina Itrić Ivanda Department of fundamental 10000 Zagreb, Croatia Faculty of Graphic Arts Getaldićeva 2 +385 1 2371 080 / 120 10000 Zagreb, Croatia marina.vukoje@grf.unizg.hr +385 1 2371 080 / 260 katarina.itric.ivanda@grf.unizg.hr 573 COMPUTER GENERATED GRAPHICS AND ANIMATION 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION FROM VIDEO TO CHARACTER ANIMATION FOR 3D THEATER PRODUCTION: A PILOT STUDY Tamara Ilić1, Bojan Banjanin1 and Jelena Kerac1 1University of Novi Sad, Faculty of Technical Sciences, Serbia Abstract: Bringing 3D characters to life has evolved significantly in digital animation. This pilot study explores the potential of Wonder Dynamics’ Animation / Video to 3D Scene project type for creating 3D theater experiences. This tool converts live-action footage into editable computer-generated environments with synchronized character animations and camera setups. Using theatrical performances from the Tragic Talkers dataset as references, animations were generated and exported as Blender scenes for visual comparison with the original footage. Results show that while monologues had minor discrepancies, mainly in facial expressions and hand positioning, interaction scenes exhibited noticeable inaccuracies in hand positioning and character interactions. These findings highlight the platform’s strengths and limitations in recreating theatrical motion and provide a foundation for future advancements in AI-driven digital theater production. Keywords: 3D characters, 3D theater, computer-generated settings, Wonder Dynamics, Animation / Video to 3D Scene 1. INTRODUCTION Artificial intelligence (AI) has changed the animation industry by automating animation processes and scene generation. Character animation has evolved significantly with AI-driven tools (Tang and Chen, 2024). One of the key challenges in AI-assisted animation is the generation of realistic character motion. Since character animation consists of a sequence of humanoid poses, AI must ensure both spatial and temporal smoothness to maintain realism (Sadat Mirzaei et al, 2020). 3D animation involves multiple steps where efficiency improvements are essential. However, despite AI’s growing role in automating aspects of animation, studies focusing on its actual impact on production efficiency remain limited. Deep learning techniques allow creation of complex 3D models within limitations, while AI-driven tools streamline rigging and enable motion synthesis based on motion capture data (Chen et al, 2024). These advancements are important for animation production workflows with well-defined parameters. However, creative tasks still rely on human expertise, highlighting the current limitations of AI (Weingarten et al, 2020). Furthermore, the increasing use of AI also raises concerns regarding the balance between efficiency and artistic manner. The future of animation lies in the integration of human creativity and AI technology (Jia, 2024). Exploring the benefits and challenges of AI in animation helps clarify how technological advancements can support, rather than replace, artistic expression. Beyond animation, AI’s role in motion tracking and automation can contribute to creative possibilities in virtual theater productions (Reynolds and Reason, 2012). The integration of AI-driven digital animation allows for interactions between virtual characters and live actors, expanding the creative possibilities of stage performances. The incorporation of multimedia components into theater creates a form of artistic expression that blends classical theatrical with modern digital aesthetics, redefining the nature of performance art in the digital era (Tonkoshkura, 2022). However, achieving performance authenticity is difficult, especially when it comes to capturing the hand movements, interpersonal interactions and micro expressions (Andreadis et al, 2010). Wonder Dynamics introduced a new type of project Animation / Video to 3D Scene which facilitates the creation of complete computer-generated (CG) scenes through a simplified workflow. This project type processes a sequence of shots within a scene and produces a synchronized animated sequence. The platform supports multi-cut videos and maintains spatial continuity of characters and camera positions. It enables the export of scene data, including motion capture, character animations, environment models, and camera tracking data, to software like Blender, Unreal Engine, and Maya (Wonder Studio, 2025). This study explores the feasibility of using Wonder Dynamics' Animation / Video to 3D Scene project type for 575 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia Unreal Engine, and Maya (Wonder Studio, 2025). This study explores the feasibility of using Wonder Dynamics' Animation / Video to 3D Scene project type for 3D theater production, addressing questions of motion accuracy and character interaction. By examining the capabilities and limitations of this AI- 3D theater production, addressing questions of motion accuracy and character interaction. By examining the based workflow, the research aims to contribute to ongoing discussions on AI’s role in digital capabilities and limitations of this AI-based workflow, the research aims to contribute to ongoing discussions on performance capture. AI’s role in digital performance capture. 2. MATERIALS AND METHODS 2. MATERIALS AND METHODS The purpose of this study was to find video material that represents theater movements and use them as The purpose of this study was to find video material that represents theater movements and use them as references for creating animations. The videos were provided by researchers from the Centre of references for creating animations. The videos were provided by researchers from the Centre of Vision, Speech, Vision, Speech, and Signal Processing at the University of Surrey. The dataset "Tragic Talkers" and Signal Processing at the University of Surrey. The dataset "Tragic Talkers" represents the Romeo and Juliet represents the Romeo and Juliet drama captured with multi-camera setups and microphone arrays. It drama captured with multi-camera setups and microphone arrays. It includes conventional acting scenarios, such includes conventional acting scenarios, such as monologues, dialogues between two individuals (actor as monologues, dialogues between two individuals (actor and actress), and dynamic interactions. The dataset and actress), and dynamic interactions. The dataset includes 30 sequences captured from 22 distinct includes 30 sequences captured from 22 distinct perspectives (Berghi et al, 2022). The videos feature multiple perspectives (Berghi et al, 2022). The videos feature multiple camera perspectives, including one-cut camera perspectives, including one-cut recordings that document monologues, dialogues, and interactions recordings that document monologues, dialogues, and interactions between Romeo and Juliet. For this between Romeo and Juliet. For this study, these videos were used as references to generate animations that study, these videos were used as references to generate animations that represent monologues, represent monologues, dialogues and interactions. The video files were uploaded in mp4 format to the Wonder dialogues and interactions. The video files were uploaded in mp4 format to the Wonder Dynamics Dynamics platform. The monologue videos had an average duration of 13.33 seconds, while the dialogue videos platform. The monologue videos had an average duration of 13.33 seconds, while the dialogue videos averaged 9.17 seconds. Monologues were used in their entirety as provided in the dataset, while interaction averaged 9.17 seconds. Monologues were used in their entirety as provided in the dataset, while sequences were trimmed to focus on key moments. Animation / Video to 3D Scene project type’s workflow is interaction sequences were trimmed to focus on key moments. Animation / Video to 3D Scene project divided into four sections: Edit, Actor, Environment, and Export. The Edit section allows adjustments to imported type’s workflow is divided into four sections: Edit, Actor, Environment, and Export. The Edit section videos, while the Actor section identifies actors within the frame and allows the user to assign digital characters allows adjustments to imported videos, while the Actor section identifies actors within the frame and to them. In this study, pre-rigged characters from the platform were used. In the Environment section, two options allows the user to assign digital characters to them. In this study, pre-rigged characters from the platform are currently available in the beta version: City Street and Empty Environment. The Empty Environment was were used. In the Environment section, two options are currently available in the beta version: City Street selected for this study to allow additional customization. The Export section provides export options, including a and Empty Environment. The Empty Environment was selected for this study to allow additional complete 3D scene or individual elements like AI motion capture and camera tracking data. The execution of the customization. The Export section provides export options, including a complete 3D scene or individual project involved several steps, including: preparing the project, extracting video, detecting cuts, video preparation, elements like AI motion capture and camera tracking data. The execution of the project involved several tracking actors, tracking actors across cuts, capturing motion, camera tracking, cleaning up motion capture, hands steps, including: preparing the project, extracting video, detecting cuts, video preparation, tracking motion capturing, hands motion cleanup and scene data preparation. Project type provided information about actors, tracking actors across cuts, capturing motion, camera tracking, cleaning up motion capture, Tracking are exported from videos that represent actors' monologue, actor and actresses’ conversation and their information about cameras, objects, ground, reflection, shadow catcher, ambient occlusion and lights. Blender scenes and Camera Tracking are exported from videos that represent actors' monologue, actor cameras, objects, ground, reflection, shadow catcher, ambient occlusion and lights. Blender scenes and Camera hands motion capturing, hands motion cleanup and scene data preparation. Project type provided in Figure 1. and actresses’ conversation and their interactions. For this study, animations were created from interactions. For this study, animations were created from recordings captured by cameras 1 and 21, as shown recordings captured by cameras 1 and 21, as shown in Figure 1. a b c d Figure 1: a) Interaction video captured with camera 1, b) Interaction video captured with camera 21, Figure 1: a) Interaction video captured with camera 1, b) Interaction video captured with camera 21, c) Male monologue captured with camera 1, d) Male monologue captured with camera 21 c) Male monologue captured with camera 1, d) Male monologue captured with camera 21 The animations were exported as Blender scenes (blend format) for comparison with the original videos. The animations were exported as Blender scenes (blend format) for comparison with the original videos. Blender Blender version 3.4.1 was used to import and analyze the animations. Footages from the database were version 3.4.1 was used to import and analyze the animations. Footages from the database were used to generate used to generate the animations and were played side by side to compare the results in 30 fps. the animations and were played side by side to compare the results in 30 fps. Animations in blend format were Animations in blend format were created separately. created separately. 2 576 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 3. RESULTS AND DISCUSSION 3. RESULTS AND DISCUSSION Monologue recordings exhibited minimal movement, primarily involving facial expressions and limited hand Monologue recordings exhibited minimal movement, primarily involving facial expressions and limited gestures, while interaction scenes featured more dynamic movements. Monologues would be analysed first, hand gestures, while interaction scenes featured more dynamic movements. Monologues would be followed by interactions. analysed first, followed by interactions. In the recording titled “malemonologue1_t1 - cam1”, it was observed that the animated character fails to blink In the recording titled “malemonologue1_t1 - cam1”, it was observed that the animated character fails in sync with the reference video, as shown in Figure 2a and 2b, due to the fact that the actor’s eyes remain to blink in sync with the reference video, as shown in Figure 2a and 2b, due to the fact that the actor’s in shadow for most of the recording. Additionally, multiple instances were identified where the actor’s thumb eyes remain in shadow for most of the recording. Additionally, multiple instances were identified where penetrated through the index finger and other fingers. Furthermore, the actor’s left hand (the one closer to the the actor’s thumb penetrated through the index finger and other fingers. Furthermore, the actor’s left camera) is clenched into a loose fist, whereas in the animation, the hand appears consistently outstretched hand (the one closer to the camera) is clenched into a loose fist, whereas in the animation, the hand (Figures 2c and 2d). appears consistently outstretched (Figures 2c and 2d). a b c d Figure 2: Figure 2: a) Animated character’s blinking detection inaccuracy, b) Animated character’s finger detection inaccuracy, c) Actor’s a) Animated character’s blinking detection inaccuracy, b) Animated character’s finger detection inaccuracy, c) Actor’s hand positioning, d) Animated character’s hand positioning hand positioning, d) Animated character’s hand positioning reveals that the animation inaccurately represents the left hand, as shown in Figures 3a and 3b. Moreover, the Moreover, the thumb's penetration into the other fingers is noticeable in the footage captured from this thumb's penetration into the other fingers is noticeable in the footage captured from this alternate angle. The video alternate angle. The video "malemonologue2_t1 - cam1" confirms the limitations in detecting finger "malemonologue2_t1 - cam1" confirms the limitations in detecting finger movements. In the video, both the right movements. In the video, both the right and left palms are slightly clenched into fists, which is not the In the video titled “malemonologue1_t1 - cam21,” a different perspective of the same monologue and frame frame reveals that the animation inaccurately represents the left hand, as shown in Figures 3a and 3b. In the video titled “malemonologue1_t1 - cam21,” a different perspective of the same monologue and and left palms are slightly clenched into fists, which is not the case in the animation. case in the animation. 3 577 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia a a b b b) Animated character’s hand positioning - camera 21 (front) b) Animated character’s hand positioning - camera 21 (front) Figure 3: Figure 3: a) Actor’s hand positioning - camera 21 (front), Figure 3 : a) Actor’s hand positioning - camera 21 (front), a) Actor’s hand positioning - camera 21 (front), b) Animated character’s hand positioning - camera 21 (front) Screenshots captured at the same frame of the video titled “interactive1_t1 - cam1” reveal discrepancies in Screenshots captured at the same frame of the video titled “interactive1_t1 - cam1” reveal discrepancies Screenshots captured at the same frame of the video titled “interactive1_t1 - cam1” reveal discrepancies in hand positioning, as shown in Figures 4a and 4b. In the animation, the woman's fingers intersect with in hand positioning, as shown in Figures 4a and 4b. In the animation, the woman's fingers intersect with hand positioning, as shown in Figures 4a and 4b. In the animation, the woman's fingers intersect with her other her other hand, and the intended positioning—where her hand rests over the man's—is not accurately her other hand, and the intended positioning—where her hand rests over the man's—is not accurately hand, and the intended positioning—where her hand rests over the man's—is not accurately maintained. In the maintained. In the video, the man firmly grasps the actress's hand with both hands, while her other hand maintained. In the video, the man firmly grasps the actress's hand with both hands, while her other hand video, the man firmly grasps the actress's hand with both hands, while her other hand naturally moves over his. naturally moves over his. Additionally, the woman's hand is positioned farther from the man's, making it naturally moves over his. Additionally, the woman's hand is positioned farther from the man's, making it Additionally, the woman's hand is positioned farther from the man's, making it seem as though he is not holding it. seem as though he is not holding it. Throughout the animation, their hands do not make contact, as seem as though he is not holding it. Throughout the animation, their hands do not make contact, as Throughout the animation, their hands do not make contact, as shown in Figures 4c and 4d. An animation created shown in Figures 4c and 4d. An animation created using the video “interactive1_t1 - cam21” as a shown in Figures 4c and 4d. An animation created using the video “interactive1_t1 - cam21” as a using the video “interactive1_t1 - cam21” as a reference confirms the claim. reference confirms the claim. reference confirms the claim. a a b b c c d d Figure 4: a) Hand placement during actor’s and actress’ interaction, b) Hand placement during animated character’s interaction, Figure 4: a) Hand placement during actor’s and actress’ interaction, b) Hand placement during Figure 4: a) Hand placement during actor’s and actress’ interaction, b) Hand placement during c) Holding hands - reference, d) Holding hands - result animated character’s interaction, c) Holding hands - reference, d) Holding hands - result animated character’s interaction, c) Holding hands - reference, d) Holding hands - result In the video “interactive2_t1 - cam1”, the actor touches the actress's back, but in the animation, the model doesn’t In the video “interactive2_t1 - cam1”, the actor touches the actress's back, but in the animation, the In the video “interactive2_t1 - cam1”, the actor touches the actress's back, but in the animation, the model doesn’t make contact and simply continues moving, likely because the actress obstructed the make contact and simply continues moving, likely because the actress obstructed the view, as shown in Figures model doesn’t make contact and simply continues moving, likely because the actress obstructed the view, as shown in Figures 5a and 5b. This interaction is further confirmed by the footage named 5a and 5b. This interaction is further confirmed by the footage named "interactive2_t1 - cam21". Furthermore, in view, as shown in Figures 5a and 5b. This interaction is further confirmed by the footage named the video “interactive4_t1 - cam1”, the actors are depicted making physical contact in the video. However, in the animation, they are not positioned close enough to touch and simply pass by each other without making contact, as shown in Figures 5c and 5d. 4 4 578 29–30 May 2025, Ljubljana, Slovenia "interactive2_t1 - cam21". Furthermore, in the video “interactive4_t1 - cam1”, the actors are depicted making physical contact in the video. However, in the animation, they are not positioned close enough to touch and simply pass by each other without making contact, as shown in Figures 5c and 5d. a b c d c) Proximity among actors - reference, d) Proximity among animated characters - result Figure 5: Figure 5: a) Actor’s hand placement, b) Animated character’s hand placement a) Actor’s hand placement, b) Animated character’s hand placement c) Proximity among actors - reference, d) Proximity among animated characters - result 4. CONCLUSIONS 4. CONCLUSIONS The results indicate that the project type successfully generates synchronized animations from video The results indicate that the project type successfully generates synchronized animations from video footage footage but faces limitations when applied to the recreation of theatrical movements. While general body movement is properly detected, particularly in scenes without interactions, minor inconsistencies in but faces limitations when applied to the recreation of theatrical movements. While general body movement is finger positioning and facial expressions are noticeable. Interactions among actors posed the greatest properly detected, particularly in scenes without interactions, minor inconsistencies in finger positioning and facial challenge, especially when holding hands. Despite these challenges, Wonder Dynamics’ Animation / expressions are noticeable. Interactions among actors posed the greatest challenge, especially when holding Video to 3D Scene project type is considered a promising tool for generating animation out of video. hands. Despite these challenges, Wonder Dynamics’ Animation / Video to 3D Scene project type is considered a However, achieving authentic performance representation in theatrical contexts still requires human promising tool for generating animation out of video. However, achieving authentic performance representation intervention. This pilot study serves as initial research of the Animation / Video to 3D Scene project type in theatrical contexts still requires human intervention. This pilot study serves as initial research of the Animation and its potential applications in theater animation workflows. While the current research focuses on / Video to 3D Scene project type and its potential applications in theater animation workflows. While the current visual data, future studies will consider quantitative metrics to strengthen the analysis. research focuses on visual data, future studies will consider quantitative metrics to strengthen the analysis. 5. ACKNOWLEDGMENTS 5 This research has been supported by the Ministry of Science, Technological Development and Innovation (Contract No. 451-03-65/2024-03/200156) and the Faculty of Technical Sciences, University of Novi Sad through project “Scientific and Artistic Research Work of Researchers in Teaching and Associate Positions at the Faculty of Technical Sciences, University of Novi Sad” (No. 01-3394/1). 579 29–30 May 2025, Ljubljana, Slovenia 6. 5. REFERENCES Andreadis, A., Hemery, A., Antonakakis, A., Gourdoglou, G., Mavridis, P., Christopoulos, D. and Karigiannis, J. 2010. “Real-Time Motion Capture Technology on a Live Theatrical Performance with Computer Generated Scenery.” Proceedings of the 14th Panhellenic Conference on Informatics 148-152. Berghi, D., Volino, M. and Jackson, P. 2022. “Tragic Talkers: A Shakespearean Sound and Light-Field Dataset for Audio-Visual Machine Learning Research.” Proceedings of the 19th ACM SIGGRAPH European Conference on Visual Media Production 1-8. Chen, Y., Wang, Y., Yu, T., and Pan, Y. 2024. “The Effect of AI on Animation Production Efficiency: An Empirical Investigation Through the Network Data Envelopment Analysis” Electronics 13 (24): 5001. Jia, H. 2024. “The application and impact of artificial intelligence in the field of animation as well as the existing disadvantage.” Transactions on Computer Science and Intelligent Systems Research 5: 660-671. Reynolds, D. and Reason, M. 2012. Kinesthetic Empathy in Creative and Cultural Practices. University of Chicago Press: Intellect Ltd. Sadat Mirzaei, M., Meshgi, K., Frigo, E. and Nishida, T. 2020. “AnimGAN: A Spatiotemporally-Conditioned Generative Adversarial Network for Character Animation” Tang, M. and Chen, Y. 2024. “AI and animated character design: efficiency, creativity, interactivity.” The Frontiers of Society, Science and Technology 6 (1) Tonkoshkura, O. 2022. “Theatre in the Age of Digital Technologies.” ARTISTIC CULTURE. TOPICAL ISSUES 30-35. Weingarten, E., Meyer, M., Ashkenazi, A. and Amir, O. 2020. “Human Experts Outperform Technology in Creative Markets.” She Ji: The Journal of Design, Economics, and Innovation 6 (3) 301-330. Wonder Studio. 2025. Wonder Dynamics. URL: https://wonderdynamics.com/ (last accessed on 18. 01. 2025). ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Tamara Ilić Bojan Banjanin Faculty of Technical Sciences Faculty of Technical Sciences Department of Graphic University of Novi Sad University of Novi Sad Department of Graphic Engineering and Design Engineering and Design Trg Dositeja Obradovića 6 Trg Dositeja Obradovića 6 21000, Novi Sad, Serbia 21000, Novi Sad, Serbia +381 21/485-2634 bojanb@uns.ac.rs +381 21/485-2559, tamarailic@uns.ac.rs Jelena Kerac University of Novi Sad Faculty of Technical Sciences Department of Graphic Engineering and Design Trg Dositeja Obradovića 6 21000, Novi Sad, Serbia +381 21/485-2559 jelena.kerac@uns.ac.rs 580 29–30 May 2025, Ljubljana, Slovenia ORAL PRESENTATION VISUALIZATIONS IN COMPUTER GRAPHIC – A COLLABORATIVE BRIDGE BETWEEN MUSEUM AND HIGHER EDUCATION RESEARCH INSTITUTION Tanja Nuša Kočevar1, Aleksandra Nestorović2 and Helena Gabrijelčič Tomc1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia 2 Regional Museum Ptuj–Ormož, Slovenia Abstract: Visualizations in computer graphics have transformed the landscape of cultural heritage preservation and interpretation. They serve as both a methodological tool and a communication bridge between museums and academic institutions. The aim of this paper is to present the importance of visualizations in computer graphics as a pivotal element in the communication strategies fostering cooperation between museums and higher education research institutions engaged in computer-aided planning and design. The study explores how visualizations in computer graphic facilitate non-invasive, accurate, repeatable, and controllable processes in cultural heritage conservation, documentation, presentation, and interpretation. Using the collaboration between the Provincial Museum Ptuj - Ormož and the Chair of Information and Graphic Arts Technology (Faculty of Textiles, Graphic Arts, and Design) as a case study, we present mutual motivations, the establishment of professional-scientific dialogues, multidisciplinary involvement, and the strategic dissemination of research outcomes through scientific platforms. Keywords: museum, higher education institution, collaboration strategy, computer generated visualisation, cul-tural heritage. 1. INTRODUCTION Visualizations, ranging from 3D reconstructions and immersive virtual reality environments to interactive digital maps and augmented reality applications, have revolutionized the ways in which cultural artifacts and historical narratives are presented to both academic audiences and the general public (Vidrih, 2019; Perko, 2022). These technologies not only enhance the accessibility and engagement of cultural content but also provide innovative methodologies for research, education, and collaborative exploration. The significance of visualizations in cultural heritage extends beyond mere representation. They serve as dynam-ic tools that enable the reconstruction of lost or damaged artifacts, the simulation of historical environments, and the detailed analysis of complex archaeological data. Through visual storytelling, museums and cultural institu-tions can create compelling narratives that bridge the gap between past and present, making history tangible and relatable. Moreover, visualizations foster inclusivity, allowing diverse audiences to interact with cultural heritage in meaningful ways, irrespective of geographical or physical limitations (Popadić, 2017; Selčan Božič, 2023). The presented contribution examines communication framework developed over years of collaboration on cultur-al heritage research, focusing on computer graphics visualizations. Using the Provincial Museum Ptuj – Ormož (PMPO) and the Chair of Information and Graphic Arts Technology (KIGT) as a case study, it highlights unique communication models that optimize cooperation, enhance research impact, and support interdisciplinary en-gagement. 581 29–30 May 2025, Ljubljana, Slovenia 2. EXPERIMENTAL In the experimental phase a structured communication strategy was designed and implemented to strengthen institutional collaboration and enhance the visibility and societal relevance of research outcomes. This strategy was directly aligned with the museum’s documentation, presentation, and interpretation processes, which were conveyed through computer-generated visualizations. Five core components were identified and operationalized: Mutual motivation, the establishment of a professional-scientific dialog: Interdisciplinary workshops and collaborative meetings were held regularly to establish a sustained professional-scientific dialogue among stake-holders. These sessions facilitated goal alignment, expectation clarification, and the cultivation of mutual trust, fostering an effective and cohesive collaborative environment. Research tenders and inter-institutional support: Strategic actions were taken to identify relevant national opportunities. Joint proposals and institutional agreements were developed, providing financial support and rein-forcing a foundation for long-term collaboration. The introduction of multidisciplinarity and the involvement of students in the implementation work: Teams composed of professionals in museology, computer science, education, and environmental studies were formed. Students participated actively in implementation phases—including content design, AR development, and test-ing—thereby enhancing innovation and skill development. The targeted planning of exhibition opportunities: Public exhibitions were planned in alignment with research milestones. These interactive showcases, integrating augmented reality components, served as engagement tools and evaluation opportunities, enabling feedback-driven refinement. Academic dissemination: Research findings were disseminated through presentations at international confer-ences and publications in peer-reviewed journals. These efforts aimed to ensure academic rigor, promote knowl-edge exchange, and contribute to the broader research community. 3. RESULTS AND DISCUSSION 3.1 Mutual motivation and the establishment of a professional-scientific dialog As a cultural institution with a focus on expanding the scope of the significance of cultural heritage, the museum is the starting point from which the research challenge arises (3D reconstructions, presentations of heritage objects, etc.). Research and higher education institutions, on the other hand, need challenges from practice, which include the work of researchers, educators (if the institution is pedagogically oriented), and students. This partnership is crucial for ensuring the scientific accuracy, authenticity, and educational value of visual content. Museums provide access to invaluable collections, curatorial expertise, and historical context, while research institutions contribute cutting-edge technological tools, methodological rigor, and interdisciplinary approaches. In the 2018/19 school year, the collaboration between PMPO and KIGT began in the form of pedagogical-re-search work. The aim and purpose was to examine the starting points, references and literature about Panorama, the central part of Petoviona (an ancient Roman city located on the present-day site of Ptuj). Based on the list presented in Figure 1, 17 groups of students from the Master’s degree program in Graphic and Interactive Com-munication created visualizations throughout the semester (Figure 1). On this basis, the PMPO representative was able to continue the study of the buildings, layout and appearance of the historical elements of the Roman city centre. 3.2 The search for research tenders and inter-institutional support The cooperation between both institutions was based on the agreement of the representatives of both institutions in terms of working methods, enthusiasm for the work, technical agreements, work organization and the trans-parency of the transfer of information from the field of archaeology to visualizations in computer graphics and vice versa. Over the years of cooperation, the permanent representatives of the cooperation group have been two experts in the field of computer graphics and visualization and one archaeologist. The research team also temporarily included experts in geology, photogrammetry expert, a historian, a fashion and textile designer and an expert in color management. The search for research tenders took place at national level, whereupon we applied for the “Student innovative projects for social benefit” tender for 2019 and 2020 and successfully completed the 582 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia research work. In the following years, the collaboration was driven primarily by the goal of presenting the results at national and international exhibitions (which is described below). inventory of objects, artifacts and buildings intended for reconstruction dishes and glassware a circumambulating sanctuary dedicated to Jupiter schematic representation of the city and Roman costume commercial buildings Figure 1: Figure 1: The list of objects, artifacts and buildings given by museum for reconstruction and first The list of objects, artifacts and buildings given by museum for reconstruction and first visualisations made by visualisations made by students. students. 3.3 Student Involvement and Multidisciplinarity 3.3 Student Involvement and Multidisciplinarity Involving students in research implementation enriched their academic experience and fostered the development of practical skills. Collaborative research offered students hands-on opportunities to apply Involving students in research implementation enriched their academic experience and fostered the development theoretical knowledge in real-world contexts, enhancing their problem-solving abilities and professional of practical skills. Collaborative research offered students hands-on opportunities to apply theoretical knowledge competencies. Multidisciplinary approaches, integrating fields such as museology, archaeology, in real-world contexts, enhancing their problem-solving abilities and professional competencies. Multidisciplinary computer science, and graphic design, broadened the scope of research and created comprehensive approaches, integrating fields such as museology, archaeology, computer science, and graphic design, broad educational environments. This diversity of perspectives encouraged innovative solutions and fostered -ened the scope of research and created comprehensive educational environments. This diversity of perspectives a deeper understanding of complex cultural heritage issues. Students gained valuable experience encouraged innovative solutions and fostered a deeper understanding of complex cultural heritage issues. Stu working in interdisciplinary teams, preparing them for diverse career paths.-dents gained valuable experience working in interdisciplinary teams, preparing them for diverse career paths. The presented research work involved students' participation of regular curricula of 1st and 2nd level study programmes and extracurricular performance work. On the basis of this experience, we were able The presented research work involved students’ participation of regular curricula of 1st and 2nd level study pro-to gain some insights into the advantages and disadvantages of involving students in the research grammes and extracurricular performance work. On the basis of this experience, we were able to gain some methods mentioned. In a full-time study research, the number of students was larger, so that the amount insights into the advantages and disadvantages of involving students in the research methods mentioned. In a of archaeological content to be worked on for reconstruction, interpretation and reproduction could be full-time study research, the number of students was larger, so that the amount of archaeological content to be gre ater, but in this case the work results (in terms of motivation, diligence and willingness to learn) of worked on for reconstruction, interpretation and reproduction could be greater, but in this case the work results (in student groups were very different, so that it was more difficult to bring the results to a common terms of motivation, diligence and willingness to learn) of student groups were very different, so that it was more denominator. For a teacher and a professional staff member, supervising a larger number of students difficult to bring the results to a common denominator. For a teacher and a professional staff member, supervising was also more demanding in terms of organization, time and pedagogical skills. When students were a larger number of students was also more demanding in terms of organization, time and pedagogical skills. When involved in extracurricular work, the work was more focused, the number of students involved was students were involved in extracurricular work, the work was more focused, the number of students involved was smaller and the students were additionally supported by paid student work. We believe that at the beginning of the collaboration is optimal to carry out the research work with a larger number of students if possible and thus obtain a wider range of possible outcomes, and then narrow down the objectives of the research and work with a smaller number of more motivated students as part-time research. In the 583 3 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia smaller and the students were additionally supported by paid student work. We believe that at the beginning of the collaboration is optimal to carry out the research work with a larger number of students if possible and thus obtain a wider range of possible outcomes, and then narrow down the objectives of the research and work with a case of the collaboration between PMPO and KIGT and 3D Graphics Reconstruction of Petoviona smaller number of more motivated students as part-time research. In the case of the collaboration between PMPO research we initially involved students from the course of Advanced Computer Graphics and case of the collaboration between PMPO and KIGT and 3D Graphics Reconstruction of Petoviona and KIGT and 3D Graphics Reconstruction of Petoviona research we initially involved students from the course Visualizations course at the 2nd level of g research we initially involved students from the course of Advanced Computer Graphics and raphics studies (25 students), and we continued with the of Advanced Computer Graphics and Visualizations course at the 2nd level of graphics studies (25 students), and research Visualizations course at the 2nd level of g work Student innovative projects for social benefit (Figure raphics studies (25 students), and we continued with the 2 ), in which, in addition to 6 students we continued with the research work Student innovative projects for social benefit (Figure 2), in which, in addition of Graphic design research work Student innovative projects for social benefit (Figure , students of Fashion and Textile Design and Geology (3 students) also participated. 2 ), in which, in addition to 6 students to 6 students of Graphic design, students of Fashion and Textile Design and Geology (3 students) also participat-One Master's student subsequently obtained a Master's degree on this topic. of Graphic design , students of Fashion and Textile Design and Geology (3 students) also participated. Figure 3 present the visual ed. One Master’s student subsequently obtained a Master’s degree on this topic. Figure 3 present the visual and and topological upgrades of the 3D objects that were previously modelled and textures. One Master's student subsequently obtained a Master's degree on this topic. Figure 3 present the visual topological upgrades of the 3D objects that were previously modelled and textures. and topological upgrades of the 3D objects that were previously modelled and textures. Rome costume Roman soldier Rome costume Roman soldier warehouse Domus warehouse Domus Panorama, view 1 Panorama, view 2 Panorama, view 1 Panorama, view 2 Figure 2: Interdisciplinary research work results Student innovative projects for social benefit (Jerneja Figure 2: Figure 2: Sotlar, Maruša Možina, Ferdi Jajai, Špela Košir; mentors: Helena Gabrijelčič Tomc, Tanja Nuša Interdisciplinary research work results Student innovative projects for social benefit (Jerneja Sotlar, Maruša Možina, Interdisciplinary research work results Student innovative projects for social benefit (Jerneja Sotlar, Maruša Možina, Ferdi Jajai, Špela Košir; mentors: Helena Gabrijelčič Tomc, Tanja Nuša Ferdi Jajai, Špela Košir; mentors: Helena Gabrijelčič Tomc, Tanja Nuša Kočevar, Aleksandra Nestorović). Kočevar, Aleksandra Nestorović) . Kočevar, Aleksandra Nestorović). hill Panorama from a bird's eye view view of the Panorama from the top of the hill hill Panorama from a bird's eye view view of the Panorama from the top of the hill Domus with courtyard and atrium Domus with private thermal baths and atrium Domus with courtyard and atrium Domus with private thermal baths and atrium courtyard Figure 3: courtyard Results of Master thesis on the topic of 3D reconstruction of ancient city Poetovio (Jerneja Sotlar; mentors: Helena Gabrijelčič Tomc, Tanja Nuša Kočevar, Aleksandra Nestorović). 4 584 4 29–30 May 2025, Ljubljana, Slovenia Regarding student involvement, we had excellent experiences in collaborating with extracurricular cooperation, which involves highly motivated students with the aim of enriching subject-specific competences. In this way, we and the institution collaborated on research into the graphic reconstruction of ancient mosaics (presented in Figures 5 and 6). 3.4 The targeted planning of exhibition opportunities Exhibitions served as public-facing platforms to showcase the interdisciplinary outcomes of our collaborations. They offered opportunities to engage broader audiences, promoted cultural awareness, and demonstrated the practical applications of academic research in real-world settings. Exhibitions also helped in building public sup-port, which were crucial for future funding opportunities. The results of the mentored student research Student innovative projects for social benefit and the master’s thesis were presented at the exhibition Osrčje Petovione in Ptuj, which is shown as a 360 exhibition in Figure 4. Figure 4: Illustrations of a soldier and horse equipment made by students in the research work (PMPO, 2020). The inter-museum and international exhibition Women’s Stories presented the results of the graphic reconstruc-tion of the mosaic with scenes of the abduction of Europa (Figure 5), which was also awarded the prestigious Valvasor award for museum achievements. Figure 5: Animation with the graphical reconstruction of the mosaic with scenes of the abduction of Europa (authors of the reconstruction and animation: Gregor Oštir, Anže Mrak, mentors: Helena Gabrijelčič Tomc, Tanja Nuša Kočevar, Aleksandra Nestorović) (PMPO, 2022). The exhibition as part of Museum night at the Regional Museum in Koper in June 2024 also hosted the results of the graphic reconstruction of Dionysus, Glory to Life, where we exhibited a reconstruction of a mosaic with animal emblems (Figure 6). 585 29–30 May 2025, Ljubljana, Slovenia 29–30 May 2025, Ljubljana, Slovenia exhibition animated presentation graphical reconstruction of the mosaic with animal emblems reconstructed mosaic's animal emblems Figure 6: Figure 6: Graphic reconstruction of a Roman mosaic with animal emblems (author of the Graphic reconstruction of a Roman mosaic with animal emblems (author of the reconstruction: Gregor Oštir; mentors: reconstruction: Gregor Oštir; mentors: Helena Gabrijelčič Tomc, Tanja Nuša Kočevar, Aleksandra Helena Gabrijelčič Tomc, Tanja Nuša Kočevar, Aleksandra Nestorović). Nestorović). 3.5 Academic dissemination Targeted planning of conferences and scientific journals for publishing research outcomes was a crucial com-3.5 Academic dissemination ponent of the communication strategy. Disseminating research findings through reputable platforms not only enhanced academic recognition but also contributed to the broader scientific discourse on cultural heritage and Targeted planning of conferences and scientific journals for publishing research outcomes was a crucial digital technologies. Presenting at conferences provided opportunities for networking, knowledge exchange, and component of the communication strategy. Disseminating research findings through reputable platforms feedback from peers, which could inform and improve ongoing and future research. Publication in high-impact not only enhanced academic recognition but also contributed to the broader scientific discourse on journal ensured that research findings reached a wide, international audience, increasing their visibility and im cultural heritage and digital technologies. Presenting at conferences provided opportunities for -pact. The results of the collaborative research have been published at 3 national conferences in the field of graph networking, knowledge exchange, and feedback from peers, which could inform and improve ongoing -ics and digital media and in one scientific impact factor (SCI) journal in the field of applied sciences (Oštir, 2024). and future research. Publication in high-impact journal ensured that research findings reached a wide, In addition, we have also presented the results of our work in 3 professional articles in the field of archaeology. international audience, increasing their visibility and impact. The results of the collaborative research have been published at 3 national conferences in the field of graphics and digital media and in one scientific impact factor (SCI) journal in the field of applied sciences (Oštir, 2024). In addition, we have 4. CONCLUSIONS also presented the results of our work in 3 professional articles in the field of archaeology. This research underscores the impact of computer-generated visualizations in cultural heritage, demonstrating 4. CONCLUSIONS their role in enhancing interdisciplinary research and dissemination impacts. By integrating 2D and 3D recon-This research underscores the impact of computer-generated visualizations in cultural heritage, structions of objects of cultural heritage the collaboration between PMPO and KIGT optimized institutional part-demonstrating their role in enhancing interdisciplinary research and dissemination impacts . By nerships, expanded research outreach, and fostered presentation and interpretation methodologies. The paper integrating 2D and 3D reconstructions of objects of cultural heritage the collaboration between PMPO highlights key communication and collaboration focuses, including mutual motivation, student involvement, tar-and KIGT optimized institutional partnerships, expanded research outreach, and fostered presentation geted exhibitions, and scholarly dissemination. The collaborative framework not only ensured the authenticity of and interpretation methodologies. The paper highlights key communication and collaboration focuses, digital heritage content but also enriched educational experiences of mentors and students. Through exhibitions including mutual motivation, student involvement, targeted exhibitions, and scholarly dissemination. The and academic publications, the results reached wider audiences, reinforcing the significance of interdisciplinary collaborative framework not only ensured the authenticity of digital heritage content but also enriched cooperation in preserving and interpreting cultural artifacts. The study provides a replicable model for future re educational experiences of mentors and students. Through exhibitions and academic publications, the -search, demonstrating how harmony in cooperation and technological advancements can bridge the gap between results reached wider audiences, reinforcing the significance of interdisciplinary cooperation in archaeological research, education and public engagement. preserving and interpreting cultural artifacts. The study provides a replicable model for future research, demonstrating how harmony in cooperation and technological advancements can bridge the gap between archaeological research, education and public engagement. 6 586 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES Oštir, G., Javoršek, D., Stergar, P., Kočevar, T. N., Nestorović, A., & Gabrijelčič Tomc, H. 2024. “Graphic Reconstruction of a Roman Mosaic with Scenes of the Abduction of Europa. ” Applied Sciences 14(9), 3931. Perko, V. 2022. Družbena vloga (slovenskih) muzejev in kulturne dediščine. Muzeji in muzejska zakonodaja, SMD. Pokrajinski muztej Ptuj - Ormož. Občasna razstava Osrčje Petovione. URL: https://pmpo.si/wp-content/themes/pmpo/virtual-gallery/ Petoviona/index.html (last accessed on 5.3. 2024). Pokrajinski muztej Ptuj - Ormož. 2022. Ženske zgodbe, medmuzejska razstava. URL: https://www.gorenjski-muzej.si/zenske-zgodbe-evropa-semitska-mati-evropejcev/ (last accessed on 5.3. 2024). Popadić, M. M. 2017. The Origin and Legacy of the Concept of Musealit. URL: https://cyberleninka.ru/article/n/the-origin-and-legacy-of-the-concept-of-museality/viewer (last accessed on 2.12. 2024). Selčan Božič, A. 2023. “StoryTeching—Immersing into the Past through the Digital Interpretation of Heritage. ” In MuseoEurope International Symposium; Koprivnik, V., Salecl, D., Eds.,168–169. Maribor Regional Museum: Maribor, Slovenia. Vidrih Perko, V., Terčon, N., Bonin, F. 2019. Muzeji in njihova vloga v sodobni družbi, In Muzeji in njihova vloga v sodobni družbi : zbornik / XIX. zborovanje SMD, Verena Vidrih Perko, V., Terčon, N., Bonin, F. Eds., Slovensko muzejsko društvo. ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Helena Gabrijelčič Tomc Aleksandra Nestorović Graphic Arts and Design 2250 Ptuj, Slovenia 2000, Ptuj, Slovenia Department of Textiles Regional Museum Ptuj–Ormož Faculty of Natural Sciences +386 (0)2 787 92 34 and Engineering aleksandra.nestorovic@pmpo.si University of Ljubljana Aškerčeva cesta, 12 Tanja Nuša Kočevar 1000, Ljubljana, Slovenia Department of Textiles, Graphic Arts and Design + 386 1 200 3 291 Faculty of Natural Sciences helena.gabrijelcic@ntf.uni-lj.si and Engineering University of Ljubljana Aškerčeva cesta, 12 1000, Ljubljana, Slovenia + 386 1 200 3 280 tanja.kocevar@ntf.uni-lj.si 587 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION INTERPRETATION OF STOP-MOTION ANIMATION IN 3D COMPUTER TECHNIQUE Ivana Pika Schlegl1, Andrej Iskra1 and Tanja Nuša Kočevar1 1University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: Animating physical puppets and 3D animation have lots of differences, since they are two different animation techniques. However, some animation studios are recreating stop motion style in a 3D world. With this research we aimed to identify the best tools and techniques for achieving this aesthetic. The paper explores replicating the stop-motion style digitally using a 3D program, resulting in a short 3D animation. The theoretical section examines why are we as the audience attracted to the style of stop motion. Key stylistic features of stop-motion were analysed and applied in Blender, utilizing various tools and add-ons to achieve the desired effect. The animation was later edited in Adobe Premiere Pro. The results were evaluated by comparing traditional and digital techniques. Findings highlight the importance of interpolation, material creation, and render engine selection. During the making of the animation a useful Blender add-on was identified as particularly effective in simulating stop-motion within a 3D environment. Keywords: stop motion, animation, 3D computer graphics, stylistic features 1. INTRODUCTION The development of technology over the years has introduced innovations in animation techniques, thereby also enhancing the production of traditional stop-motion animation. Although 3D animation dominates today, stop-motion animation has a unique charm that still captivates the audience. This article describes the creation of an animation that attempts to replicate stop-motion style digitally. The objective was to explore the most effective ways to replicate this style using a 3D graphics program and to identify the tools that help us achieve that. The anticipated result was a short 3D animation in the stop-motion style. We focused on understanding the differences between traditional and 3D stop-motion animation, particularly in terms of production methods, time requirements, and visual outcomes. 1.1 Stylistic features of stop motion Stop-motion is a technique where objects are physically manipulated and photographed after each movement. This method, known as frame-by-frame animation, creates the illusion of motion when a sequence of frames is played (Gong, 2023). A film is not merely an audio-visual experience (Langan, 2023). While textures in films cannot be physically touched - similarly to art pieces in galleries, where touching is typically prohibited - artists explore ways to evoke tactile sensations visually. Stop motion animations often incorporate materials from everyday life. Utilizing familiar textures brings the film closer to the audience, fostering a sense of connection as viewers can relate to the materials through prior experiences. By employing textures from daily life, filmmakers create an emotional resonance, enhancing relatability and engagement. (Minnan, 2020). This phenomenon, termed haptic visuality, refers to the process where the observation of specific textures triggers memories, allowing viewers to “feel” materials through visual perception and past experiences (Langan, 2023). 588 29–30 May 2025, Ljubljana, Slovenia Stop-motion typically uses a frame rate of 12 frames per second. (Laybourne, 1998) The distinctive choppy movement resulting from a lower frame rate is one of the most recognizable stylistic features of stop-motion animation (Teh, 2023). Creators often seek to replicate this effect in digital animation to emulate the stop-motion style (Thill, 2023). As mentioned, stop-motion animation inherently reflects the creator’s touch. Puppets and models are manually crafted and moved, leaving behind visible fingerprints and sewn clothing. Everyday objects are often repurposed during filming. These imperfections are not flaws but rather expressions of real-world presence (Langan, 2023). Finally, stop-motion animation evokes childhood memories of storytelling and playing with toys, giving viewers the feeling of nostalgia. It represents a dreamlike scenario where toys come to life. It is proven that as technology advances, the appreciation for handmade creations grows stronger. We tend to value objects crafted with significant effort and dedication. 2. EXPERIMENTAL Our short animation is about a fox which comes into a living room, where different objects are placed. The fox, unfamiliar with its surroundings, begins to disrupt the setting. For 3D modelling and animating we used program Blender, which is free software for 3D graphics. After 3D modelling all the objects, we focused on different ways to achieve realistic look of the objects. Some of the materials were created using image-based textures and others were done manually. Two procedural materials were sourced from online repositories as this is also a way to achieve realistic material. Special attention was given to simulating clay, which was the material used for the main character. We wanted to animate a material with transformative properties and focused on developing a realistic clay texture and movement. Using UV mapping, we customized the fox character’s surface with the function ‘Smart UV Project’. This way we could apply fingerprint texture to simulate tactile imperfections, adding relief to enhance depth and reduce shine in certain areas. 2.1 Walk Cycle Animation While adding bones to the character, we referenced a pre-existing wolf skeleton in Blender. Walk cycle animation relied on sketches of various walking phases, which guided the bone adjustments. Each step required positioning the fox in ten poses. To create forward motion, we shifted the character along the Y-axis in each keyframe, ensuring consistent paw placement between frames. Constant interpolation was used for movement transitions. This approach mirrors traditional stop-motion, where the puppet is repositioned and photographed after each adjustment. 2.2 Keymesh Animation The fox was animated using a combination of armature movement and the Keymesh plugin, developed by Pablo Dobarro and available on GitHub (GitHub). Keymesh allows frame-by-frame mesh deformation, akin to physically reshaping clay between shots. This technique closely resembles traditional stop-motion animation. Armature animation alone led to artifacts (Figure 1a), which we corrected using Keymesh (Figure 1b). The combination of bones for basic motion and Keymesh for fine-tuning was effective. 589 29–30 May 2025, Ljubljana, Slovenia Figure 1: Artifacts on the character (a) and their reduction after using the plugin (b) 2.3 Animating other objects Each object was animated according to the material from which it was made. We had to consider how each specific material would move in reality – fabric wrinkles softly, denim is stiffer, cardboard boxes flatten, etc. Movements where objects only change location or rotation were animated by inserting keyframes in Object mode. When the fox jumps onto the cardboard boxes and flattens them, we again used the Keymesh plugin and flattened the box in each frame using the Grab tool in Sculpt mode. Similarly, we animated the wrinkling of fabric using the Cloth tool, which simulates the wrinkling or falling of textile. For all the movements of the objects, which we carried out during this project, we used constant interpolation. Constant interpolation directly transitions from one keyframe to the next, without adding any intermediate frames or transitions. This type of interpolation is also the technique used to achieve the stop-motion animation style, as it functions in the same way as moving a puppet and taking a photograph after each movement. Since this interpolation results in very abrupt transitions from one pose to another, we had to ensure that we included enough keyframes for each movement to make it appear cohesive, yet still imperfect enough to resemble classic stop-motion animation. The title animation was created in the style of claymation, also using Blender. We wanted the word “Fox” to appear as if the letters were gradually being shaped from clay. For this part of the animation, we exclusively used the Keymesh plugin. For each letter, we started with a subdivided cube, which we shaped using the Grab tool in Sculpt mode. With the plugin, we inserted new keyframes and slightly reshaped the letter in each frame, so that in the end, the word was fully formed. Figure 2 shows the clay title in the program. 590 29–30 May 2025, Ljubljana, Slovenia Figure 2: Animating the title 2.4 Rendering and post-production In our case Eevee rendered clay textures more convincingly, preserving details like fingerprints. In contrast, Cycles diminished these details, making fingerprints less visible even at high sample rates. We exported our animation in image format. After exporting all the images, we imported them into Adobe Premiere Pro, as we first needed to convert them into a video. In the program, we set the animation speed to 12 frames per second. We set the duration of each imported image to 1, meaning each image lasted for one frame in the video. This gave us the final animation. If we wanted to duplicate or extend the duration of any keyframe, we changed the image’s duration to 2, with the Ripple Edit function enabled, which adjusts the duration of an individual frame without affecting the others. 3. RESULTS AND DISCUSSION Our goal was to replicate stop-motion animation using digital tools. The clay title sequence and character (Figure 3) were particularly successful, achieving a convincing stop-motion aesthetic. Intentional imperfections added realism, reflecting changes typical of physical clay models. Figure 3: Clay material that was used in the final animation 591 29–30 May 2025, Ljubljana, Slovenia Some other materials lack the charm of stop motion, making it more apparent that they were created in a 3D environment. The cardboard box was the least convincing due to texture visibility issues. The movement successfully mimicked stop-motion’s non-smooth flow. We avoided poses unachievable with real puppets, such as mid-air jumps. Instead, we split the jump into segments where the character always maintained ground contact. Comparing traditional and digital stop-motion, traditional setups require fully prepared scenes and fixed lighting before shooting, as changes are difficult to implement later. In contrast, digital scenes allow continuous adjustments, saving time and enabling error correction even after rendering. 3D software also simplifies character manipulation, providing comprehensive viewing angles—an advantage over physically handling miniature models. Throughout this project, we aimed to identify the tools and techniques that would best help us achieve the stop-motion animation style. Keymesh plugin proved highly effective, whether used alone (as in the title animation) or in combination with the skeleton rig. In this case, we used it to correct errors, ensuring that the character maintained its shape in all poses, or to add a clay-like effect. We used the frame-by-frame technique, meaning that in each keyframe, we manually adjusted the position of the character or objects. This type of animation is more time-consuming than letting the program calculate the movements and add intermediate keyframes, but it allowed us to achieve the stop-motion style, as traditional stop-motion animation is also created frame by frame. The key to achieving the recognizable, non-smooth movement of characters, as seen in stop-motion animation, is the use of constant interpolation. Of all the interpolation options in the program, this one most closely resembles the sequence of photographs that would be taken in traditional animation. We also considered to set the right number of frames per second, as too many frames would result in overly smooth movement, which would cause us to lose one of the key characteristics of stop-motion animation. For exporting such an animation, it is suitable to export it in an image format, which does not export a video, but rather each keyframe separately. This way, we can also control the frames per second in post-production. If the movement appears too fast in some areas, we can duplicate keyframes. 4. CONCLUSIONS During this research, we explored the most recognizable stylistic features of stop-motion animation. We aimed to replicate these characteristics and the style of such animation using a 3D animation software, while also identifying the best tools and techniques to achieve this. In the experimental section, we gained a deeper understanding of Blender and the process of creating 3D animation within it. During production, we tested a combination of different animation techniques and analysed which one yielded the best results and why. Throughout the project, we engaged with the entire process of creating such an animation and observed the critical role post-production plays in achieving the desired outcome. The final outcome aligned with our expectations. The project highlighted numerous advantages of digital animation production, including a faster and ultimately more cost-effective process (considering the costs of materials in traditional stop-motion animation). However, each technique has unique merits, and both should be preserved to celebrate their distinct creative advantages. Computers and technology can successfully complement and enhance traditional stop-motion animation, but the digital realm should not entirely replace it. 592 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES GitHub, URL: https://github.com/pablodp606/keymesh-addon/. Gong, Y. The blend of reality and illusion – analysis of the artistic characteristics of stop-motion animation. URL: https://www.atlantis-press. com/proceedings/iclahd-22/125984403 (last accessed on 25. 1. 2024). Langan, H. The appeal of stop motion in the digital age. URL: https://onshow.iadt.ie/wp-content/uploads/sites/6/2023/04/The-Appeal-of-Stop-Motion-in-the-Digital-Age.pdf (last accessed on 24.1.2024). Laybourne, K.1998. The animation book: a complete guide to animated filmmaking--from flip-books to sound cartoons to 3- D animation. New York : Three Rivers Press. Minnan, C., Yizhe, T. in Shenglu, a.X. Analysis of visual language for stop-motion animations. URL: https://www.e3s-conferences.org/ articles/e3sconf/abs/2020/39/e3sconf_ewre2020_02104/e3sconf_ewre2020_02104.html> (last accessed on 17. 1. 2024). Teh, S., Perumal, V. in Hamid, H.A. Investigating how frame rates in different styles of animation affect the psychology of the audience. URL: https://mmupress.com/index.php/ijcm/article/view/721 (last accessed on 24. 1. 2024). Thill, S. An imperfect world: an interview with the directors of Flushed Away. URL: https://www.popmatters.com/an-imperfect-world-interview-with-sam-fell-and-david-bowers-directors-of-fl-2495740124.html (last accessed on 27.1.2024). ADDITIONAL DATA ABOUT AUTHORS Corresponding author: Co-author(s): Ivana Pika Schlegl Dr. Andrej Iskra, senior lecturer Graphic Arts and Design Faculty of Natural Sciences and Engineering Chair of Information and Department of Textiles, University of Ljubljana Graphic Arts Technology Department of Textiles, Faculty of Natural Sciences Snežniška ulica 5 Graphic Arts and Design and Engineering 1000, Ljubljana, Slovenia University of Ljubljana 01/20 03 222 andrej.iskra@ntf.uni-lj.si Ass. Dr. Tanja Nuša Kočevar University of Ljubljana Faculty of Natural Sciences and Engineering Department of Textiles, Graphic Arts and Design Snežniška ulica 5 1000, Ljubljana, Slovenia 01/20 03 280 tanja.kocevar@ntf.uni-lj.s 593 29–30 May 2025, Ljubljana, Slovenia POSTER PRESENTATION WIDESPREAD VISUALIZATIONS WITH 3D TECHNOLOGIES Boris Beja1, Lan Fabjan1, Tis Loris Lavrič1, Eva Lap1 and Žiga Ceglar1 1 University of Ljubljana, Faculty of Natural Sciences and Engineering, Slovenia Abstract: The project explores maritime heritage and reflects on how to transform photographic material into a virtual spatial experience for the contemporary museum visitor. Today, museum presentations of artefacts and exhibits are enhanced by animations and simulations that complement the museum experience. On one hand, we explored the interiors and the companies that built and co-designed the ship‘s interiors. On the other hand, we aimed to draw attention to the rich art collection of General Navigation, which has been shaped by Slovenian artists. Among these, on Slovenian ships, we find the sculptural works of Stojan Batič, who, with his characteristic expression and signature style, furnished the Ljubljana, Bela Krajina, Ljutomer, Kras, Postojna, Portorož (I) and (II), and Trbovlje. While interpreting the photographic material, we experimented with surface treatments of the created objects, the choice of materials and colours, and tried to relate the realisations to the aesthetics of the 1950s and 1960s. At the outset, we had only black and white photographs as sources for modelling. Key-words: Sculpture, virtual space, Slovenian ships, cultural heritage, art on ships. 1. INTRODUCTION The Maritime Museum Sergej Mašera Piran prepared the exhibition Slovenian Ships, 6 Ships of Splošna plovba in 2020. Splošna plovba also devoted considerable attention to the art used to decorate the interior spaces of its ships. The art collection was built through donations from the communities after which the ships were named and through public procurement by General Navigation. Formally and conceptually, the ship’s godfathers intended for the artworks to interpret the traditions and history of the towns after which the ships were named. Alongside many artists who decorated Slovenian ships with their works - Avgust Černigoj, Lojze Spacal, Zvest Apollonio, and Zoran Mušič - we focused particularly on the artistic heritage of Stojan Batič (Žitko, 2020). Stojan Batič (1925) had left a significant mark on his homeland with his sculptural works. He imprinted a wide variety of themes into clay. Initially figurative and marked by realism, his works later evolved into a distinctive authorial expression, almost scenographic in scale. The surfaces of his sculptures resemble branching scenes, carved close to the body, where various surface treatments unfold across the limited dimensions of the relief. Particularly striking is his use of surface as a compositional key - layering and sometimes using perspective. De-spite the abstract appearance, Batič never neglected proportions or anatomical relationships in his depictions of individuals and groups (Čopič, 2000). Batič contributed artworks to the ships Trbovlje (1960), Bela Krajina (1961), Ljubljana (II) (1964), Ljutomer (1965), Karst (1967), Postojna (1967), Portorož (I) (1968), and Portorož (II) (1986). In our research, we focused on Ljubl-jana (II) and Portorož (I). The motor ship Ljubljana (II), built at the Uljanik shipyard, was the fastest vessel in the fleet at the time. It measured 148.4 metres in length, 19.6 metres in width, and had a deadweight of 9,139 tonnes. In one of its salons, we find a sculptural relief Najada (1964), preserved in aluminium in the General Navigation collection (Žitko, 2020). In the salon of the motor liner Portorož (I), we encounter Batič‘s Deklici (1968). The work depicts two female figures holding hands in a pronounced longitudinal composition. The surface is intricately decorated with the graf-fiti-like markings that the sculptor often integrated into his works. Also built in the Uljanik Pula shipyard, the motor liner Portorož (I) was 147.8 metres long, 20 metres wide, and had a deadweight of 11,230 tonnes (Žitko, 2020). 594 29–30 May 2025, Ljubljana, Slovenia Figure 1: Deklici (1968), aluminium, 90 cm x 20 cm x 21 cm. Photography plays a significant role in printmaking, especially with the introduction of silkscreen techniques in artistic expression and image reproduction. Transferring photographs to printing matrices expanded the colour palette for graphic communication, particularly in poster design, where office printers first enabled montage and collage layouts (Bernik, 1989). In contemporary augmented and virtual spaces, photography becomes a tool for capturing and algorithmically adapting data into comprehensive visual „objects.“ Beyond its artistic value, photography serves as a document of the past, interpreting and explaining historical spaces in the context of time. Unsurprisingly, it is used in fields like ethnology and archaeology to build databases exploring heritage. Photography is also linked to restoration: modern software and technical tools help document restoration processes or objects. For example, Michelange-lo‘s David was digitally scanned in Florence, enabling researchers to study the surface treatment of the Carrara marble (University of Florence, 2020; Madeline, 2021). 3D technologies have also been used for Batič‘s public monuments in Trbovlje, such as the Monument to the Revolution and the Orjuna Monument. The company 3Dpro specialises in virtual walkthroughs, 360-degree pho-tography, mapping, and preparing point-cloud models (ZMT, 2022). 3D capture of sculptural forms is used for creating replicas or reconstructing missing parts. It‘s important to note that reproductions do not replace original artworks but serve as templates for educational or museum use. These techniques have largely replaced tradi-tional copyists, reducing costs and making tactile materials more accessible - especially to the blind and visually impaired. 2. EXPERIMENTAL Museum presentations of artefacts and exhibits are nowadays complemented by animations and various simu-lations that enhance the exhibition material. On one hand, this project explored ship interiors and the companies that built and co-designed them. On the other hand, we aimed to highlight the rich art collection of General Navi-gation, shaped by the contributions of Slovenian artists. Two works of art were recreated in the experiment. Deklici was captured using Polycam software. The relief was modelled through observation using Blender and Nomad Sculpt. The data, along with the artworks’ dimensions, enabled us to establish a scale both for the furniture and for the recreation of the selected space. The sculptural and relief templates, with their specific dimensions, served as a reference for scaling and interpre-ting the extended spaces, initially conveyed to us through photographic documentation of the interiors. Photo-graphy conveys various types of information - about space, time, and, not least, about people. If, in architectural representations, the human body is often used as a scale, in our case we chose to scale the space in relation to the artworks within it. Space is limitless, yet constrained by human intention and creativity, allowing objects to exist within it and be moved through it. In our case, what was once self-evident was transferred into the realm of imagination, because the photographic reference alone did not provide a complete representation or experience of the space. Space, therefore, was no longer a given, taken for granted (Muhovič, 2015). 595 29–30 May 2025, Ljubljana, Slovenia The black and white photographs gave us a sense of depth through the use of grey tones. Using spatial cues such as overlapping and converging lines, we began to construct an imagined volume where the photograph failed to capture it. Our view was mediated by the photographer, but we used our own imagination to reconstruct the missing parts of the ship’s interior. We aimed to offer the viewer a holistic experience of the chosen salon, inclu-ding those walls and perspectives that were undocumented or lost from photographic archives. The frontal plane presented in the image had to be extended by its imagined mirror behind it, thus completing the spatial cross the photographer once occupied. His sensory experience was replaced and supplemented by our own, enriching the two-dimensional image with an impression of depth, spatiality, and the plasticity of objects (Butina, 1995). While interpreting the grey photographic material, we experimented with the surface treatment of 3D objects, the selection of materials and colours, and aimed to relate our reconstructions to the aesthetics of the 1950s and 1960s. Initially, our only modelling sources were low-resolution black and white photographs, lacking any indication of scale. We determined colours based on those most frequently used in the mid-20th century, refe-rencing catalogues and architectural monographs from that era. For furniture dimensions, we relied on standard measurements, researching the design solutions of companies such as Stol Kamnik and Meblo Nova Gorica. We were also aided by colour photographs from General Navigation’s archives and the original 1964 plan of the ship Ljubljana, which provided scale and helped us reconstruct the unseen space behind the photographic lens. A major focus of the creative process was capturing the sculptural object Deklici (1968) with Polycam software. The captured data was processed and scaled in 3D augmented space using Blender, and the sculpture was placed within the reconstructed interior. In the case of Najada (1964), we experimented with relief modelling in Blender and Nomad Sculpt. The photographic reproduction offered insight into the relief’s shadows and sculptural drawing - its interplay of rough and smooth surfaces. We struggled to determine the true depth of the relief and to grasp the sculptor’s impressions in the clay, which were cast in aluminium in the original. These challenges were addressed using comparable relief works by Batič that were available to us. Textures were rendered using a custom brush, allowing us to harmonise surface variations and build the best possible digital interpretation of the sculptor’s composition. Both works were placed within reconstructed interiors, based on photographic references and ship plans. While interpreting the grey material, we experimented with the surface treatment of 3D objects, the choice of ma-terial and colours, and tried to relate the realisations to the aesthetics of the 1950s and 1960s. At the beginning, we had only black and white photographs as modelling sources, which were of poor resolution and without scale. We tried to determine the colours based on those most commonly used in the 1950s and 1960s, which were avai-lable to us in the form of catalogues and architectural monographs. For the size of the furniture, we used standard measurements, researching the design solutions of the companies Stol Kamnik and Meblo Nova Gorica. We also used colour photographs of the Splošna Plovba and the original 1964 plan of the ship Ljubljana, which provided a scale with which we could construct the image behind the photographic lens. A major focus of the creative process was the capture of the sculptural object Deklice (1968) with Polycam softwa-re. The captured data was further surface-processed with Blender and presented to scale in a 3D augmented space and the sculptural object was placed in the created interior. In Najada (1964), we experimentally undertook relief modelling in Blender and Nomad Sculpt, and we present the process in layers in Figure 3. The photographic reproduction of the work offered us a reading of the relief in the shadows and the sculptural drawing, the relation-ship of rough and smooth surfaces. We struggled to assess the depth of the relief structures and the sculptor‘s impressions in the clay, which in the original were cast in aluminium. The challenges of the depth structure of the relief were solved on the basis of other sculptor‘s solutions that were available to us. The textures were rendered with a created brush, which offered us the opportunity to coordinate the variety and build the best possible repre-sentation of the sculptor‘s composition. Both depictions were placed in interiors, which we depicted with examples of photographic images and ship plans. 596 29–30 May 2025, Ljubljana, Slovenia Figure 2: Relief created using Blender and Nomad Sculpt. In rendering the interior, we used photographic material to determine light sources and reflections from smooth surfaces, which guided our choices of materials and textures. The original wooden floors were replaced with ne-edlefelt carpet and linoleum, based on period accuracy. We also had to construct additional spatial boundaries to complete the room, further guided by the layout and orientation of objects in the ship’s salon. This process allowed us to reconstruct a complete volume and spatial experience, into which the visitor - equipped with VR glasses - could be immersed. The spatial cross, once occupied by the photographer, was reconstructed as an interactive experience. 3. RESULTS WITH DISCUSSION The results, presented in three different modelled spatial reconstructions, offer an expanded museum presenta-tion based on the original content. The exhibition included short documentary films by Viba Film, noted for their strong artistic sensibility. This inspired us to also present the reconstructed spaces as video documentaries, where space could be experienced through time. Digital tools were used to ensure the content could be displayed and accessed online. Alongside the recreated sculptural works, we produced 3D models that make the ship’s interiors accessible to the public, including virtual walkthroughs for the blind and visually impaired. This research is an effort to preserve and reinterpret the memory of our maritime heritage. Figure 3: View of the expanded space in Blender with the Deklici statue. 597 29–30 May 2025, Ljubljana, Slovenia The video animations and digital spaces form a dramaturgy of space, guided not by a photographer, but by the creator of the expanded environment. This designer incorporates light, texture, and object arrangement to sha-pe the final experience. The musical background further enhances the visual impression of the virtual space, dictating its rhythm and tone. In one of our experiments, the animation ends with a visualisation of a degraded interior: furniture has been rearranged, and graffiti from urban settings covers the walls. In doing so, we drew a connection between private and public space, linking the history of these interiors with the eventual scrapping and abandonment of Slovenian ships. Figure 4: View of Salon 1 and Blender view of the degraded graffiti area. 4. CONCLUSIONS The Maritime Museum Sergej Mašera Piran prepared the exhibition Slovenian Ships, 6 Ships of General Na-vigation in 2020, which now includes a contribution we developed using black and white archival material. Our intention was to create an expanded spatial narrative through photographic sources and to share a simulation with those who never had the opportunity to experience the ship interiors firsthand. While we carefully considered the materials used in furnishing interior walls and furniture, our primary focus was on the artworks—now digitally rendered and made viewable from all directions, much like Batič’s own approach when shaping his sculptures in evolving clay forms. Most of the General Navigation ships are preserved only in reduced scale as physical models. Our aim was to offer a deeper glimpse into their interiors, allowing VR glasses to provide museum visitors with an enriched experience of industrial heritage and spatial design. One of our goals was also to make cultural heritage—often housed in private collections—more accessible, and to present it in the highest quality visual forms and digital templates. By digitising small sculptural works, we have extended the reach of Batič’s oeuvre, which has predo-minantly been accessible only through his public monumental sculptures. Now, in a 360-degree virtual space, with options for zooming and interacting, selected works are available to researchers and admirers of Slovenian modernist figurative art alike. 598 29–30 May 2025, Ljubljana, Slovenia 5. REFERENCES: Bernik, S. (1989), Plakat & znak, vodilni temi slovenskega sodobnega oblikovanja vidnih sporočil. Ljubljana: Sinteza Čopič, Š. (2000), Javni spomeniki v slovenskem kiparstvu prve polovice 20. stoletja. Ljubljana: Moderna galerija Madeleine, P, A. 2021. “3D printed replica of Michelangelo’s statue of David presented at the Dubai World Expo, 3D Natives”. (obtained by [24. 1. 2025]). Muck, D., & Križanovskij, I. (2015). 3D-tisk. 1. izd. Ljubljana: Pasadena. Muhovič, J. (2015). Leksikon likovne teorije: slovar likovno-teoretskih izrazov z ustreznicami iz angleške, nemške in francoske terminologije. Celje: Celjska Mohorjeva družba. Smyth, C. (2015). Functional design for 3D printing. Alaska: C. T. Smyth. Stephen, H. (2018). 3D Printing for Artists, Designers and Makers. London: Bloomsbury Visual Arts. University in Florence and the Hexagon group. 2020. “3D printed reproduction of Michelangelo’s sculpture of David” (obtained by www.theflorentine.net/2021/01/05/michelangelo-david-expo-dubai/> [20. 1. 2025]). Žitko, D. (2020). Slovenske ladje: 6 ladji Splošne Plovbe. Piran: »Sergej Mašera« Piran. Watson, F. (1982). The history of furniture. London: Obris ADDITIONAL DATA ABOUT AUTHORS Corresponding author Co-author(s): Boris Beja Eva Lap Tis Loris Lavrič Department of Textiles, Department of Textiles, Department of Textiles, Graphic Arts and Design, Graphic Arts and Design Graphic Arts and Design Chair of Information and Chair of Information and Faculty of Natural Sciences Graphic Arts Technology Graphic Arts Technology and Engineering Faculty of Natural Sciences Faculty of Natural Sciences University of Ljubljana University of Ljubljana University of Ljubljana 1000, Ljubljana, Slovenia Aškerčeva 12 and Engineering and Engineering Aškerčeva 12 Aškerčeva 12 Žiga Ceglar 1000, Ljubljana, Slovenia 1000, Ljubljana, Slovenia Department of Textiles, +386 1 470 4500 Department of Textiles, Lan Fabjan Graphic Arts and Design Faculty of Natural Sciences boris.beja@ntf.uni-lj.si Graphic Arts and Design and Engineering Faculty of Natural Sciences University of Ljubljana and Engineering Aškerčeva 12 University of Ljubljana 1000, Ljubljana, Slovenia Aškerčeva 12 1000, Ljubljana, Slovenia 599