Editing Ultraviolet (section)

===Fluorescent dye uses===
Colorless [[fluorescent dyes]] that emit blue light under UV are added as [[optical brightener]]s to paper and fabrics. The blue light emitted by these agents counteracts yellow tints that may be present and causes the colors and whites to appear whiter or more brightly colored.

UV fluorescent dyes that glow in the primary colors are used in paints, papers, and textiles either to enhance color under daylight illumination or to provide special effects when lit with UV lamps. [[Blacklight paint]]s that contain dyes that glow under UV are used in a number of art and aesthetic applications.{{cn|date=May 2024}}

Amusement parks often use UV lighting to fluoresce ride artwork and backdrops. This often has the side effect of causing rider's white clothing to glow light-purple.{{cn|date=May 2024}}

[[File:RBC Visa UV.jpg|right|thumb|A bird appears on many Visa credit cards when they are held under a UV light source.]]
To help prevent [[counterfeiting]] of currency, or forgery of important documents such as driver's licenses and [[passports]], the paper may include a UV [[watermark]] or fluorescent multicolor fibers that are visible under ultraviolet light. Postage stamps are [[Phosphor banded stamp|tagged]] with a phosphor that glows under UV rays to permit automatic detection of the stamp and facing of the letter.

UV fluorescent [[dye]]s are used in many applications (for example, [[biochemistry]] and [[forensics]]). Some brands of [[pepper spray]] will leave an invisible chemical (UV dye) that is not easily washed off on a pepper-sprayed attacker, which would help police identify the attacker later.

In some types of [[nondestructive testing]] UV stimulates fluorescent dyes to highlight defects in a broad range of materials. These dyes may be carried into surface-breaking defects by capillary action ([[liquid penetrant|liquid penetrant inspection]]) or they may be bound to ferrite particles caught in magnetic leakage fields in ferrous materials ([[magnetic particle inspection]]).