The term 'Tattoo Canvas' refers to the SKIN, which is a four letter word, that is used as the surface for a tattoo. The SKIN is the most common canvas for tattoos, as it is the body's largest organ and provides a stable surface for the ink to be applied. Tattoos are created by inserting ink into the dermis layer of the SKIN, which is the second layer of the SKIN and contains nerve endings and blood vessels.