Sunlight stable inks are not as bright as the organic inks, but will last for years under sunlight. The organic inks are much brighter and less expensive, but will fade in about 1 week if left to sit under the sun. Sunlight stable inks are phosphor dispersions or suspensions made using an acrylic binder that dries to a clear coating holding the phosphor to the surface. The phosphors are small ceramic crystals that behave similar to rock dust. They cannot be dissolved in solvents and are inert to over 1500 DegF.
UVLWG - Ultraviolet Longwave green fluorescing non-soluble powder.
UVLWR - Ultraviolet Longwave red fluorescing non-soluble powder.
UVLWB - Ultraviolet Longwave Blue fluorescing non-soluble powder.