FEBRUARY 14 - 19, 2021

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The Undyeing Swatch

Fiona Bell

The finished swatch showing the woven structure in dark blue colour, the led cables and a coin cell holder with coin cell.


The Undyeing Swatch utilizes a combination of visible Light Emmiting Diodes …LEDs) and photocatalytic nanoparticles to diminish the color of organically dyed textiles. As such, this swatch explores ‘undyeing’ as a design process that utilizes light and dye as materials for controlled interaction. The swatch itself consists of a knitted cotton I-cord coated with silver doped titanium dioxide nanoparticles …(TiO2/Ag) and dyed with hibiscus. The I-cord is used to encase a strand of LEDs and was then continuously woven into a swatch. When the LEDs are turned on, the light activates the nanoparticles which in turn break down organic matter (the dye). This swatch provides a proof of concept for the undyeing process, which I believe could be an interesting area of future exploration for HCI researchers and artists alike.

Two examples of the woven Swatch, left before exposure to light, right after 73 hours of exposure.
left: before Exposure to Light
right: after 72 hours of Exposure


Size 5/2 white 100% cotton yarn, size 7 double pointed knitting needles, USA Nanocoat multi- purpose LumaClean (i.e. TiO2/Ag), Cylaplex meter long light emitting diode …LEDˆ string lights, and hibiscus tea.


Dyeing with natural dye (hibiscus), coating with aqueous nanoparticles, knitting …I-cord), and continuous weaving where the same knitted I-cord is used in both the weft and warp directions.

Schematic drawing of the making of the swatch displaying the weaving structure on the left and the structure of the woven cord on the right - there included the twisted LEDs insight the woven strand.


I would like to acknowledge Laura Devendorf and Mirela Alistar from the University of Colorado Boulder, for their guidance and help with editing the submission, and Andreea Danielescu, Ben Greenspan, and Aditi Maheshwari from the Future Technologies R&D Group at Accenture Labs for support.





There are many potential relationships between textiles and light and the concept of “undyeing” is provocative and useful. The sample was beautifully crafted and the documentation is excellent. The author does a good job of placing their work in context and dialogue with similar work to make the case for specific innovations this swatch contributes.I find it fascinating that the photocatalytic material is a cleanser currently marketed to a world besieged by a viral pandemic. 

This swatch was awarded the INSPIRATION AWARD because it plays with and inverts ideas of tools and materials, by positioning the LED as a tool.