Tattoo removal is most commonly performed using lasers that react with the ink in the tattoo, and break it down. The broken-down ink is then absorbed by the body, mimicking the natural fading that time or sun exposure would create. This technique often requires many repeated visits to remove even a small tattoo, and may result in permanent scarring. The newer Q-switched lasers are said by the National Institute of Health to result in scarring only rarely, however, and are usually used only after a topical anesthetic has been applied. The NIH recognizes five types of tattoo; amateur, professional, cosmetic, medical, and traumatic (or natural). Areas with thin skin will be more likely to scar than thicker-skinned areas. There are several types of Q-switched lasers, and each is effective at removing a different range of the color spectrum. Whilst black is the easiest color to remove, there are various different types of lasers, and specific types have proven more useful at removing other ink colours.
Laser tattoo removal
Also worth considering is the fact that some of the pigments used (especially Yellow #7) are known to break down into toxic chemicals in the body when attacked by light. This is especially a concern if these tattoos are exposed to UV light or laser removal; the resulting degradation products end up migrating to the kidneys and liver. Laser removal of traumatic tattoos may similarly be complicated depending on the substance of the pigmenting material. In one reported instance, the use of a laser resulted in the ignition of embedded particles of firework debris.