A tattoo is a marking made by inserting indelible ink into the dermis layer of the skin to change the pigment.

Tattoos on humans are a type of decorative body modification, while tattoos on animals are most commonly used for identification or branding.

tattoo models

The first written reference to the word, "tattoo" (or Samoan "Tatau") appears in the journal of Joseph Banks, the naturalist aboard Captain Cook's ship the HMS Endeavour in 1769: "I shall now mention the way they mark themselves indelibly, each of them is so marked by their humor or disposition".