Tattoos were probably also used in ancient medicine as part of the treatment of the patient. In 1898, Daniel Fouquet, a medical doctor, wrote an article on “medical tattooing” practices in Ancient Egypt, in which he describes the tattooed markings on the female mummies found at the Deir el-Bahari site. He speculated that the tattoos and other scarifications observed on the bodies may have served a medicinal or therapeutic purpose: "The examination of these scars, some white, others blue, leaves in no doubt that they are not, in essence, ornament, but an established treatment for a condition of the pelvis, very probably chronic pelvic peritonitis."
"In the late eighteenth and early nineteenth centuries, tattoos were as much about self-expression as they were about having a unique way to identify a sailor's body should he be lost at sea or impressed by the British navy. The best source for early American tattoos is the protection papers issued following a 1796 congressional act to safeguard American seamen from impressment. These proto-passports catalogued tattoos alongside birthmarks, scars, race, and height. Using simple techniques and tools, tattoo artists in the early republic typically worked on board ships using anything available as pigments, even gunpowder and urine. Men marked their arms and hands with initials of themselves and loved ones, significant dates, symbols of the seafaring life, liberty poles, crucifixes, and other symbols."
Always pay attention to whatever the tattoo artist tells you, and do exactly what he or she instructs. If the artist is a professional, they will definitely know what kind of product and healing technique works the best for their own creation. Remember that if you change the aftercare for whatever reason it may be, the artist won’t be obliged to touch up your tattoo free of charge. It’s ultimately up to you to take care of your tattoo, once you leave the studio.
According to George Orwell, coal miners could develop characteristic tattoos owing to coal dust getting into wounds. This can also occur with substances like gunpowder. Similarly, a traumatic tattoo occurs when a substance such as asphalt is rubbed into a wound as the result of some kind of accident or trauma. These are particularly difficult to remove as they tend to be spread across several layers of skin, and scarring or permanent discoloration is almost unavoidable depending on the location. An amalgam tattoo is when amalgam particles are implanted in to the soft tissues of the mouth, usually the gums, during dental filling placement or removal. Another example of such accidental tattoos is the result of a deliberate or accidental stabbing with a pencil or pen, leaving graphite or ink beneath the skin.