A blacklight poster or black light poster is a poster printed with inks which fluoresce under a black light. The inks used contain phosphors which cause them to glow when exposed to ultraviolet light emitted from black lights.

What is the purpose of a black light?

Black lights emit long wave ultraviolet (UV) light that allows materials and substances invisible to the human eye under normal lighting to fluoresce and produce visible color and light.

Do you need a blacklight for blacklight posters?

A flocked poster has black fibers that feel felt-like. The black appears much darker than an ink with no glare and gives great contrast to the fluorescent UV reactive inks. ... Blacklight not included and is required to see the poster fluoresce or glow in the dark.