Creating Temporary Art that Feels like Magic with Photochromic Pigment

This is a post from the archives - originally published in February 2023

Photochromic pigment changes color when exposed to UV light, opening up all kinds of possibilities for ephemeral experiments with light, shadow, collage, etc. It's a versatile material that can be mixed with paint, glue, and other materials and applied to a huge variety of surfaces. I particularly like to use this to prototype and test cyanotype designs before actually creating a cyanotype print. This post documents some of the many possibilities myself and others have explored.

The big idea: I'm using a UV LED light to "paint" onto paper and other objects that are covered with a photochromic pigment mixture. This is not a permanent process. The image lasts for a minute or so before fading away. (this is kind of how transitional glasses lenses or "invisible ink" work, they change color temporarily when exposed to UV light like the sun)

When I began sharing these experiments online, several folks asked about what materials I used, and how the process works. Some folks shared their own experiments with these materials. This post collects and documents our shared explorations and some tips for getting started.

Thank you to my friends at the Tinkering Studio for this fantastic blog post & gallery . We experimented with photochromic pigment during my residency in March 2023.