I have been reading a book all about Smart Materials this morning, which I ordered with some photochromic and thermochromic materials... I am very excited to test these out to see what sorts of interesting combinations I can come up with.
Photochromic Pigments which react to UV light and change colour accordingly should be very interesting as will give the impression that an image simply appears when you step out into the sunlight. It can be mixed with any acrylic media so the possibilities for this product are very vast.
Thermochromic Materials such as smart colour pigments change colour at specific temperatures. They are based on liquid crystal technology (at certain temps the liquid crystals re-orientate which results in an apparent change of colour). The liquid crystal itself is micro-encapsulated (the tiny particles are surrounded by a coating) and billions of these capsules (10microns in diameter) can be mixed with a suitable carrier (most acrylic media) to create printing inks for fabrics.
At room temperature the pigment appears coloured but at 27oC it disappears. The colour possibilities are endless as it can be mixed with any acrylic paint to make any colour and when it heats up to over 27oC the smart colour pigment will become transparent leaving a different colour underneath. (see example above)
Glow-in-the-dark pigments are phosphorecent pigments that absorb and store energy from natural or artificial night to be expelled as a glowing image at night when their is a limited or no light supply.
It comes in a powdered form which can be mixed with an acrylic medium to form a water resistant seal around the particles. If it does not have this barrier the pigment will degrade when exposed to moisture.
Its effectiveness depends on the thickness of the print and how much is used in conjunction with the acrylic paint.
The possibilities: you can 'charge' up your garments print all day so it will 'glow' all night-an alternate image will appear at night when the glow-in-the-dark pigment takes over from the photochromic pigment.
I think that using all these different pigments in conjunction will give a single garment multiple looks see post on One t-shirt many looks...?