- For the Voyager episode see "Tattoo"
A tattoo was a type of body art, a mark or design which was placed under the skin. Tattoos were a common form of decoration amongst many races and often had some sort of cultural significance.
Some Native American groups, such as the Rubber Tree People, also wore facial tattoos, both Chakotay and his father Kolopak had tattoos of Rubber Tree design above their left eyes. (VOY episode: "Tattoo")
Chakotay's tattoo was one of his most identifying features and as such was sometimes a source of parody and imitation: In 2373 Q attempted to impress Kathryn Janeway by appearing with a much more elaborate version of Chakotay's tattoo; The Bajoran character Katanay in The Doctor's holoprogram Photons Be Free was based on Chakotay and sported an elaborate facial tattoo; In 2377 Ventu villagers on Ledos began to imitate Chakotay and Seven of Nine, which included copying Chakotay's tattoo. (VOY episodes: "The Q and the Grey", "Author, Author", "Natural Law")
Romulan tradition involved facial tattoo designs being applied to individuals in a state of mourning. While mainstream 24th century tradition usually involved a temporary paint or dye, the extreme tragedy of Romulus's destruction caused Nero's crew to permanently tattoo mourning marks onto their faces. (TOS - Countdown comic: "Issue 3")