In the western world, tattoos are made using a tattoo machine (consisting of either a single or group of needles) which can pierce the skin around 150 times per second. The needle punctures through the epidermis (the outer layer of the skin) into a layer of deeper dermal tissue situated underneath the epidermis. During each piercing, insoluble ink is inserted into this lower layer. The healing process involves the flaking away of the outer layer of skin which removes any surface pigment, whereas within the skin, granulation tissue forms which fills the wound to allow healing. This granulation tissue is finally converted into connective tissue, repairing the skin layers but leaving the ink intact.
However, over time, various biological processes can cause tattoos to fade or smudge. As well as the fact that ink descends deeper into the dermis (causing tattoo colour to fade ), the death of skin cells and their subsequent removal from the body lead to the removal of pigment from the tattoo. A third contributing factor is the division of cells leading to the movement of ink particles within the skin, and it is this process that is used in Eames’ model which attempts to show how tattoos may change over a twenty year period. This is done by modelling the way in which skin cells move the particles of ink around in the dermis, albeit at a much slower rate of only a few millimetres a year.
However, themodel shows that the process of fading can be affected by various factors such as the wearer’s skin type, exposure to the sun, and details of the tattoo itself – for example, smaller, more intricate details are affected most by the fading process as they lose their definition at a quicker rate. In fact, it is suggested that they may last as few as ten years. Thicker lines are not affected to the same extent, however.
It is hoped that the model will help health professionals understand the long-term effects of tattoos, as well as educate potential tattoo bearers to the ways in which they can help their body art last in the long-term.