• Amateur decorative tattoos are typically tapped by hand into the skin using a wire or needle resulting in a low density of ink particles that are located superficially in the skin. These are usually black in color and composed of carbon-based inks such as pen ink or burnt wood.

• Professional decorative tattoos are placed with a “tattoo gun.” These devices have a single needle or group of needles that rapidly oscillate in and out of the skin. Professional tattoos usually contain organic dyes mixed with heavy metals to give vibrant colors. For example, red is often made from mercury, yellow from cadmium, green from chromium, and blue from cobalt.

• Cosmetic tattoos are commonly referred to as “permanent makeup.” They are typically applied to eyelash margins, eyebrows, and lips to simulate makeup, and are usually combinations of colors containing pink and flesh tone inks that may be mixed with white. Flesh tones often contain iron oxide, and white commonly contains titanium dioxide or zinc oxide.

• Traumatic tattoos result from deposition of pigment in the skin by abrasion. Common causes include trauma from gravel referred to as “road rash,” pencil graphite, or by explosive forces as with shrapnel and fireworks. These materials become lodged in the dermis after reepithelialization of the wound and result in blue/black tattoos.

• Medical tattoos are placed as markers for radiation therapy. These are usually black, carbon-based inks.