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Artists create tattoos by injecting ink into a person's skin. They do this by using an electric-powered tattoo machine that resembles a dental drill. The machine moves a solid needle up and down to puncture the skin between 50 and 3,000 times per minute and is powered by a foot switch which controls the verticle movement of the needle. The needle penetrates the skin by about a millimeter and deposits a drop of insoluble ink into the skin with each puncture. We view a person's tattoo through the epidermis,which is the outer layer of skin. The ink is actually in the dermis, which is the second layer of the skin. The cells of the dermis are far more stable than the cells of the epidermis, so the tattoo's ink will stay in place, with minor fading and dispersion throughout a person whole life.