Anti-Stokes materials, or 'up-converters', absorb lower energy light and re-emit the energy as higher energy light. This is achieved by emitting one unit of high energy for every two or more units of low energy absorbed. Because this photoluminescent process is the reverse of what usually happens in phosphors and fluors, the process is said to be anti-Stokes luminescence.

The pigments in the UC range of up-converters absorb near infrared around 980nm, and emit in the visible spectrum. The activating energy should be by infrared laser, but a low powered IR diode is sufficient to activate the brighter shades at short range. The UC range does not luminesce under ultraviolet.

Application guidelines:
These pigments are insoluble and should be dispersed by high speed stirring. Limited gentle milling is possible. These pigments may be blended together, but do not blend with non-luminescent pigments or dyes, or other opacifiers, which will quench the luminescent emissions.