Blacklight paint

Blacklight paint or blacklight-reactive paint is paint that glows under a blacklight. The paint may or may not be colorful under ordinary light.

Such paints and inks are commonly used in the production of blacklight posters. Under daylight, the ultraviolet light ordinarily present makes the colors especially vivid. Under blacklight (with little of no visible light present), the effect produced can be psychedelic.

Blacklight paints are always fluorescent. More rarely, they may also be phosphorescent, continuing to glow for a time after the blacklight has been removed.

A common trade name for such paints is "Day-Glo".


The invention of blacklight painting was by the brothers Joseph and Robert Switzer in 1930s. Robert met with an accident, suffered from severe hand injury, the doctors confined him to a dark room. Joseph and his brother started to investigate on fluorescent compounds.

They brought a black light (a lamp that emits ling wave of UV light) into the storeroom of their father's drugstore looking for naturally fluorescing organic compounds and mixed those compounds with shellac (is a resin secreted by female lac bugs) to develop the first black light fluorescent paints. The first use of these paints was for Joseph's amateur magic shows.


Blacklight paints and inks are commonly used in the production of blacklight posters. Common usage of the black light pigments is in security features of money notes, various certificates printed on paper, meal coupons and tickets. The blacklight printed figures used for this purpose are usually invisible under normal lighting, even when they are exposed to direct sunlight (which contains ultraviolet light) but they show up glowing when exposed to blacklight source.

Black light paints are sometimes used in the scenery of amusement park dark rides: a black light illuminates the vivid colors of the scenery, while the vehicle and other passengers remain dimly lit or barely visible.