research into how to go about using temperature sensitive substances to change one graphic into another, it seems this was mainly used on T-shirts...
Hypercolor was a line of clothing, mainly
T-shirts and
shorts, that changed
color with heat. They were manufactured by
Generra (now a division of
Public Clothing Company) and marketed in the
United States as
Generra Hypercolor or
Generra Hypergrafix and outside the US as
Global Hypercolor. They contained a
thermochromic (
temperature sensitive) pigment made by
Matsui Shikiso Chemical of
Japan, that changed between two colors–one when cold, one when warm. The shirts were produced with several color change choices beginning in 1988.
[1] The effect could easily be permanently damaged, particularly when the clothing was washed in hotter than recommended water.
(wikipedia)
Thermochromism is the ability of
substance to change
color due to a change in
temperature. A
mood ring is an excellent example of this, but it has many other uses such as baby bottles (changes to a different color when cool enough to drink) and kettles. Thermochromism is one of several types of
chromism.
The two basic approaches are based on
liquid crystals and
leuco dyes. Liquid crystals are used in precision applications, as their responses can be engineered to accurate temperatures, but their color range is limited by their principle of operation. Leuco dyes allow wider range of colors to be used, but their response temperatures are more difficult to set with accuracy.
Paints
Thermochromic paint is a relatively recent development in the area of color-changing
pigments. It involves the use of
liquid crystal or
leuco dye technology. After absorbing a certain amount of light or heat, the crystallic or molecular structure of the pigment reversibly changes in such a way that it absorbs and emits light at a different wavelength than at lower temperatures. Thermochromic paints are seen quite often as a coating on coffee mugs, whereby once hot coffee is poured into the mugs, the thermochromic paint absorbs the heat and becomes colored or
transparent, therefore changing the appearance of the mug.
