(Erika Onodera/Strange World)
Simply because tattoos are made in one of the deepest layers of the skin, which does not undergo renewal. It is good to remember that the tissue that covers our body is formed by three main layers: the epidermis, the outermost layer; the dermis, intermediate; and the hypodermis, the deepest of all. Of the three, the only one that is in constant renewal is the epidermis. “The tattoos are done with the injection of pigments directly into the dermis, which is not renewed”, says dermatologist Solange Teixeira, from the Federal University of São Paulo (Unifesp).
Tattoo artists use thin needles that penetrate about 2 millimeters into the tissue and then inject drops of ink into the dermis. It is for this reason that tattoos do not leave the body, while a pen line, which only affects the epidermis, disappears with soap and water. However, if not done well, they can end up getting blurred over time. This occurs, for example, when the needle does not reach the dermis or when the ink is of poor quality. Designs can also lose definition due to the action of skin defense cells, which try to isolate pigments by understanding that they are an aggression to the body.