A tattoo is a marking made by inserting indelible ink into the dermis layer of the skin to change the pigment for decorative or other reasons. Tattoos on humans are a type of decorative body modification, while tattoos on animals are most commonly used for identification or branding. The term "tattoo" or from Samoa, "Tatau" is first referred to by Joseph Banks, the naturalist aboard Cook's ship the "Endeavour" in 1769 where he mentions it in his journal. To paraphrase. he states, "I shall now mention the way they mark themselves indelibly, each of them is so marked by their humor or disposition".
Tattooing has been practiced for centuries worldwide. The Ainu, the indigenous people of Japan, traditionally wore facial tattoos. Today one can find Berbers of Tamazgha (North Africa), Māori of New Zealand, Arabic people in East-Turkey and Atayal of Taiwan with facial tattoos. Tattooing was widespread among Polynesian peoples and among certain tribal groups in the Taiwan, Philippines, Borneo, Mentawai Islands, Africa, North America, South America, Mesoamerica, Europe, Japan, Cambodia, New Zealand and Micronesia. Despite some taboos surrounding tattooing, the art continues to be popular in many parts of the world.
Types of tattoos：The American Academy of Dermatology distinguishes 5 types of tattoos.Traumatic tattoos, also called "natural tattoos", that result from injuries, especially asphalt from road injuries or pencil lead(According to George Orwell, coal miners could develop characteristic tattoos owing to coal dust getting into wounds. This can also occur with substances like gunpowder. Similarly, a traumatic tattoo occurs when a substance such as asphalt is rubbed into a wound as the result of some kind of accident or trauma. These are particularly difficult to remove as they tend to be spread across several different layers of skin, and scarring or permanent discoloration is almost unavoidable depending on the location. In addition, tattooing of the gingiva from implantation of amalgam particles during dental filling placement and removal is possible and not uncommon. A common example of such accidental tattoos is the result of a deliberate or accidental stabbing with a pencil or pen, leaving graphite or ink beneath the skin); Amateur tattoos; Professional tattoos, both via traditional methods and modern tattoo machines; Medical tattoos; Cosmetic tattoos, also known as "permanent makeup".