Thermochromatic ink

Working on the Magenta Square (Arrangement in Magenta, Thermochromatic Ink, Tin and Nichrome) and Viral Wallpaper we have used different methods to apply the ink and also heat it. Below we’ve covered our process for applying and heating the link from dying to resistive heating.

purchasing   

We purchase our thermochromatic ink from a company in California called Matsui International. They require a minimum purchase of 4 kilograms so it might be best to call and ask for sample if you are unsure of a color or temperature range. Another reason we purchase from Matsui is because they are a complete pleasure to deal with. They were one of the few companies that would ship a sample to a “graduate student” who wasn’t working on a mass marketed product. We’ve posted a photograph of the different colors of ink we’ve been working with. Another great thing about Matsui is that they have the best and thickest transparent base we’ve ever worked with. We ordered a huge tub of it and mix it with acrylic ink sometimes.

the ink

The first think to realize is that most thermochromatic ink on the market today disappears after a certain temperature threshold. For example, the ink will always show until it is heated and then it will disappear. Some of the inks can be purchased at lower temperature thresholds so they color disappears in normal room temperature and changes color when it is cooled.

The inks, straight out of the bottle are very thin and runny. The ink must be mixed with a base in order for the color to disappear to clear. If you apply the ink straight out of the bottle and heat the ink it simply changes to white. The transparent base is what makes it disappear clear. If you use it without mixing it with a base it dries chalky.

Matsui recommends the following percentages for mixing the ink with base:
30 – 50% – Thermochromatic ink
70 – 50% – Base (Silk Screen Clear)
The reason for the varying percentages is because each color has different properties. For example the red need a more base or else it will dry pink if you mix it half and half. It takes a bit of experimenting but eventually you’ll get the ink to disappear exactly how you want it.

The thermochromatic ink Matsui sells is water based so it makes for easy clean up.

dying

For the Magenta Square we chose to use a soft jersey material which was really great to work with because it didn’t wrinkle too much and really held the ink. I was able to dye the 6ft x 6ft fabric with the sample ink they gave me. I mixed it with a ton of water and just dip-dyed the fabric.

dip-dyed fabric hanging to dry and then rolled flat on a sheet of white paper

The magenta ink is actually a lot darker than the final dyed color of the fabric. The above photo is a rub test of a square of magenta painted onto paper. The magenta ink isn’t mixed with a lot of base which is why it turns a the pink color instead of clear (white).

silk screening the ink

coming soon… photos and information about our experiences silk screening the ink.

heating [nichrome]

coming soon… our experiences with nichrome and the magenta square.

heating [resistive heating]

coming soon… our experiences with resistive heating using conductive paint.

Tags: thermochromatic ink

This entry was posted on Wednesday, February 3rd, 2010 at 3:43 am and is filed under hacks, special process. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.