These pigments normally have a pale, off-white appearance but in sunlight or UV light they change to a bright, vivid colour. The pigments revert to their pale colour when away from sunlight or UV light. If the pigment is mixed with a binder, such as an acrylic base, it can be permanently applied to almost any surface. The more dilute the pigment, the less dramatic the colour change. The mixing proportions are a matter of trial and error, but a 50:50 mix is a good starting point. The practical applications of the pigment are almost limitless. The active photochromic dye is contained in micron-size microcapsules dispersed in water to make up the pigment, which has the consistency of thick cream. Uses range from UV warning systems to 'smart graphics' in publications and packaging and garment design. Methods of application include brush painting, block printing, stencilling, screen printing etc. 3g supplied in a plastic syringe.
