Classic tattoo eyeliner, also known as permanent eyeliner, is a form of cosmetic tattooing where pigment is applied to the upper or lower eyelids to create the appearance of eyeliner. This technique is used to enhance the eyes by providing a defined look without the need for daily makeup application. The pigment is implanted into the skin using a fine needle, and the results can last for several years, though touch-ups may be needed to maintain the desired look.