Photochromic inks for printing
Photochromic inks are completely transparent or milky inks, which become coloured under the influence of a solar radiation (or that of a UV lamp), showing visual elements only after exposure to the light.
The effect is reversible, after the exposure to the light is ended, the inks return to their transparency.
They are used in information and advertising materials, where the task is to provide information or a visual effect only when sunlight or UV light hits the printouts.
Elements printed with photochromic inks somewhat ‘wake up to life’ together with the sun. They can also function as a warning, when the recommended doses of UV light falling on the surface of the printout are exceeded.