UV printing is a form of digital printing that uses ultra-violet lights to dry or cure ink as it is printed. As the printer distributes ink on the surface of a material (called a "substrate"), specially designed UV lights follow close behind, curing - or drying - the ink instantly. Originally developed for quickly drying gel nail polishes during manicures, ultraviolet light applications quickly expanded into industrial and commercial markets. Because the UV lights cure any printed ink immediately, the dots of wet ink do not get a chance to spread out once printed, resulting in much finer detail. In addition, UV cured inks are weather-resistant and offer increased resistance to fading.