An effective way to remove a tattoo is with a quality-switched laser. According to CNN, the laser searches for contrasts and pulses on the skin to break down the ink so that it is small enough for the body to absorb.
Laser treatment works differently on each individual. The greater the color contrast is between the skin and ink, the easier it is to remove. For example, black ink on light skin is the easiest to remove. Florescent colors are often the hardest to remove from light skin. Small and older tattoos are also easier to remove than bigger or new tattoos.