Tha habit of decorating, colouring, using and drawing on one's body as if it were a canvas is among the most ancient practices humanity could recall: ever since the dawn of mankind, human beings have impressed on themselves images and words able to convey powerful and evocative symbols.
A tattoo is the injection of coloured pigments into the dermis by means of a needle oscillating at a frequency ranging from 50 to 3000 times per second and reaching the depth of 1mm under the skin.
Dermis is the deepest skin layer and, differently from epidermis which is more exterior and subject to frequent shedding, is more stable and makes it possible to keep the tattoo for a lifetime.
Tattoos can therefore be defined as pigmented skin lesions due to coloured substances, usually introduced on purprose but sometimes even accidentally (accidental tattoos most frequently take place as a consequence of infections caused by road accidents).
Today, the practice of tattooing something on the skin is widespread, although not lacking in risks and suffering. Tattoos can be divided into four categories: prefessional tattoos, performed by a tattooing machine and usually featuring a large amount of pigment, voluntarily injected with the intended aim at recreating something on the skin; cosmetic tattoos, which simulate make up to reshape eyebrows or to make lips stand out better, just to make a few examples; post-traumatic tattoos, which are the result of an accident; finally, tattoos are employed in radiotherapy to help the localization of the areas to radiate (medical tattoos).
But people often regret what they have "carved" on their skin, resolving to remove the indelible sign created. However, the main problem with tattoo removal in the past were the scars created by dermabrasion.