Project Case

June 12, 2025

Reviving Craft with Science: A Study in Slime Mold Dye Techniques

A report on the Joint Development Retreat by Hanna Saito, Tanaka Nao Dye Shop, Misaki Shiozu, and the SPCS community

Slime mold dyeing is a technique in which pigments or dyes are mixed into the food of slime molds, allowing undigested colorants to appear in the trails left behind in their excretions. (Slime molds refer to true slime molds, or myxomycetes, which spread in an amoeba-like form.) Contemporary artist Hanna Saito has independently developed this unique method as a form of artistic expression.

In this project, experiments were conducted to further develop slime mold dyeing into a textile dyeing technique. If successful, this could open up new applications in clothing and interior textiles. However, the process must also address practical challenges such as durability against washing and friction.

To explore these possibilities, Kazuhisa Kitagawa of the historic Kyoto-based dye manufacturer Tanaka Nao Dye Shop, and Misaki Shiozu, a dyeing artist based in Hokuto City, joined the project for an intensive round of testing and validation.

This report shares highlights from the intensive development retreat held at Hokuto Bio Art Laboratory from December 2–5, 2024.

Project members 

 

 

Nestled in Hokuto City, Yamanashi Prefecture, with a view of the majestic Yatsugatake Mountains, the Hokuto Bio Art Laboratory serves as the creative base of artist Hanna Saito.

The lab is surrounded by a forest of red pines, and for this experiment, Saito used slime molds she had collected from the nearby mountains.

In this experiment, 11 types of natural and synthetic dyes, 3 species of slime molds (myxomycetes), and 3 types of textiles were combined to explore pigment fixation. Depending on environmental conditions, some species, such as Physarum polycephalum, can move up to 20 cm per hour, making visible changes possible within just a few days. The tests revealed certain combinations to be clearly incompatible, but they also led to new hypotheses. For example, researchers observed that different slime mold species appeared to interact more favorably with specific fibers or dyes.

Mr. Kitagawa, who leads dye development at the long-established Kyoto dye manufacturer Tanaka Nao Dye Shop, participated in the experiment to test pigment fixation. He prepared a variety of textiles treated with different processes, along with fixatives and dyes. (Pictured left).

Slime molds collected by Saito from the hillside behind the lab (left).

When viewed up close, you can see the slime mold moving along the fibers.

Slime mold approaching the dye-infused oatmeal bait (left), and slime mold retreating from it (right).

To apply the technique to crafts and products, it is necessary to ensure durability against washing and friction. In this experiment, pigment fixation was performed using fixatives after washing the textiles with water.

Finally, the pigments are fixed using an iron (left), and the resulting texture varies depending on the type of textile used (right).

Silk yielded the most beautiful result, with both a refined texture and delicate patterns.

A final simple test was conducted to assess rub fastness.

During the Year-End Party at FabCafe Tokyo and Kyoto in December 2024, works that successfully demonstrated pigment fixation from the experiment were on display. (Photo: Daisuke Murakami)

Through this slime mold dyeing experiment, we found that applying textile dyeing techniques makes it likely to achieve a level of quality suitable for craft applications. This project is ongoing, and we’re continuing to explore its potential. If you’re interested in applying this method to apparel, product design, or other fields, please feel free to reach out.

  • Hanna Saito

    Contemporary artist, Doctoral student at the Kakehi Laboratory, The University of Tokyo.

    Contemporary artist. Born in 1988. After graduating from the Glass Course in the Department of Crafts at Tama Art University, she joined metaPhorest, a biological/biomedia art platform, and began working in the field of bio art. Since 2019, she has been enrolled in the Master’s Program at the Graduate School of Interdisciplinary Information Studies, The University of Tokyo (Kakehi Laboratory).

    She creates works using techniques from scientific glassmaking, as well as through the use of biological materials, organic matter, and image analysis, while also engaging in academic research. In recent years, she has been collecting and cultivating multiple species of wild slime molds, incorporating them into both her artistic and research practices.

    Her main themes include rethinking the boundaries between nature and society, humans and non-humans, and exploring the inseparability of the artist and the subject of expression.

    Contemporary artist. Born in 1988. After graduating from the Glass Course in the Department of Crafts at Tama Art University, she joined metaPhorest, a biological/biomedia art platform, and began working in the field of bio art. Since 2019, she has been enrolled in the Master’s Program at the Graduate School of Interdisciplinary Information Studies, The University of Tokyo (Kakehi Laboratory).

    She creates works using techniques from scientific glassmaking, as well as through the use of biological materials, organic matter, and image analysis, while also engaging in academic research. In recent years, she has been collecting and cultivating multiple species of wild slime molds, incorporating them into both her artistic and research practices.

    Her main themes include rethinking the boundaries between nature and society, humans and non-humans, and exploring the inseparability of the artist and the subject of expression.

  • Kazuhisa Kitagawa

    Director of the Research and Development Department, Tanaka Nao Dye Shop Co., Ltd.

    Born in 1974 in Wakayama City. Graduated from Kyoto Institute of Technology and joined Tanaka Nao Dye Shop Co., Ltd. Assigned to the Research and Development Department, where he has been involved in product development, quality control, and preparation of Safety Data Sheets (SDS). Currently serves as Director of the Research and Development Department at Tanaka Nao Dye Shop Co., Ltd.

    Born in 1974 in Wakayama City. Graduated from Kyoto Institute of Technology and joined Tanaka Nao Dye Shop Co., Ltd. Assigned to the Research and Development Department, where he has been involved in product development, quality control, and preparation of Safety Data Sheets (SDS). Currently serves as Director of the Research and Development Department at Tanaka Nao Dye Shop Co., Ltd.

  • Misaki Shiozu

    Textile dyeing artist

    Graduated from the International Fashion Department, Stage Costume Design Course at Bunka Gakuen University. While working part-time at a vegetable shop, she began experimenting with extracting dyes from discarded vegetable scraps. In 2021, she relocated to Hokuto City, where she now lives in a mountain village at an altitude of 1,000 meters. There, she conducts experimental dyeing using foraged plants, natural dyes from around the world, and materials such as iron rust.

    Graduated from the International Fashion Department, Stage Costume Design Course at Bunka Gakuen University. While working part-time at a vegetable shop, she began experimenting with extracting dyes from discarded vegetable scraps. In 2021, she relocated to Hokuto City, where she now lives in a mountain village at an altitude of 1,000 meters. There, she conducts experimental dyeing using foraged plants, natural dyes from around the world, and materials such as iron rust.

  • Nami Urano

    SPCS / Loftwork Inc.

    After graduating from university, Nami joined Loftwork, where she was involved in planning and organizing business events at the Shibuya office, as well as managing industry-academia collaboration communities between Japanese companies and overseas universities. In 2020, she helped launch and manage the COUNTERPOINT residency program at FabCafe Kyoto. She is also actively engaged in articulating the activities of FabCafe’s global network and cultivating a foundation for inter-location collaboration. Since 2022, she has been responsible for launching and managing SPCS (“Species”), a community that explores the uncontrollability of nature. Her formative experiences include studying social security systems in university, learning about Denmark’s folk high schools, living in a kibbutz in Israel, and co-hosting a fermentation club with chef Momoyo Morimoto. These experiences have sparked her interest in creating chaos within spaces, cultivating environments that embrace complexity and spontaneity.

    After graduating from university, Nami joined Loftwork, where she was involved in planning and organizing business events at the Shibuya office, as well as managing industry-academia collaboration communities between Japanese companies and overseas universities. In 2020, she helped launch and manage the COUNTERPOINT residency program at FabCafe Kyoto. She is also actively engaged in articulating the activities of FabCafe’s global network and cultivating a foundation for inter-location collaboration. Since 2022, she has been responsible for launching and managing SPCS (“Species”), a community that explores the uncontrollability of nature. Her formative experiences include studying social security systems in university, learning about Denmark’s folk high schools, living in a kibbutz in Israel, and co-hosting a fermentation club with chef Momoyo Morimoto. These experiences have sparked her interest in creating chaos within spaces, cultivating environments that embrace complexity and spontaneity.

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    This articles is edited by FabCafe Global.

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