A tattoo means a permanent decorative and / or symbolic design made on the skin. Previously, it was mostly done with Indian or charcoal or tallow ink. Nowadays, inks containing industrial pigments are more used. There are inks of different colors and even a clear ink that reacts only to black light: this type of tattoo is called "UV" or "Blacklight" tattoo. The tattoo is considered a type of permanent bodily modification.
The tattoo technique consists of "injecting" the ink directly under the skin using needles or other sharp objects. The ink is thus deposited below between the dermis and the epidermis. The depth of the injection varies from 1 to 4 mm depending on the skin types and the parts of the body involved, the thickest areas are in the back of the body, on the elbows and on the knees.
Tattooing has been practiced for thousands of years all over the world. It can be done for symbolic, religious or aesthetic reasons. In many civilizations, it is even considered a rite of passage, "thanks" to the pain it entails during making. It was also a mode of marking used for the identification of slaves, prisoners or pets.
