UV Blacklight Ink :: Remember, remember, the velvet November

http://www.tattooartists.org/Gal3975_UV_Blacklight_Ink.asp

UV tattoos or blacklight tattoos are tattoos made with a special ink that is visible under an ultraviolet light (blacklight). Depending upon the ink, they can be nearly invisible in non-UV environments, thus they are a popular consideration for people seeking a subtler tattoo. They are particularly popular in the raver subculture.[citation needed]

Although the tattoos are sometimes considered invisible in normal light, scarring from the tattoo machine in the application process may remain, and therefore still show. A UV tattoo becomes visible under blacklight, when it glows in colors ranging from white to purple, depending on the ink chosen. Colored ink is also available, where the ink is visible in normal light (as with a regular tattoo) but the ink will glow vividly under UV light. However, some UV inks are not as bright under normal light as normal tattoo ink and are considered not as vibrant.