Not long ago, most Americans associated tattoos with sailors, bikers and sideshow artists. But tattoos have become more popular in recent years. What does it take to get an image under your skin?
You can see a tattoo through the skin's epidermis -- but the ink itself goes right into the dermis.
Your epidermis renews itself constantly, and ink deposited there would fade and change quickly. But ink deposited into the dermis is fairly stable. It will stay there for a person's entire life.
Tattooing is part of many indigenous cultures. The first recorded use of the word tattoo is from James Cook's records of his expedition to the South Pacific in 1769. The term comes from the Tahitian word for 'to mark.'
Even though a tattoo machine looks and sounds a little like a dental drill, its design was based on an autographic printer created by Thomas Edison. Samuel O'Reilly invented the tattoo machine in the late 1800s.
If tattoo equipment is sterile -- and people with freshly tattooed bodies care for them properly at home -- the risk of infection is relatively low. But a tattoo is basically an injury. Every time the needle enters the skin, it creates the opportunity for microorganisms to enter as well.
An autoclave uses heat and pressure to kill microorganisms. In addition to being used to clean tattoo needles, autoclaves are used to sterilize equipment in hospitals and dentist offices.
Black work is a preliminary step in most tattoos. It involves creating a permanent outline, often from a stencil, of the design. For very large tattoos, it's often practical to complete all the black work in one session and fill in the color later.
Bloodborne diseases like HIV and hepatitis make safety precautions during tattooing extremely important. If an artist needs to clean an area on a person's skin, he or she should spray the soap onto a tissue, not onto the bleeding area. This keeps blood droplets from flying through the air.
A holiday is any part of a tattoo where the ink is missing. This can happen if the ink disappears during healing or if the artist misses a spot during coloring.
Patients with tattoos have reported pain or burning during MRI procedures. Doctors also report interference around tattooed areas in some cases. Either way, the culprit is metallic particles in the tattoo ink.