There are two compounds available for black pigment: carbon black, which is often used by body–art technicians, and iron-oxide black, most often used by permanent-makeup technicians.
Carbon black, also known as lamp black, bone black and thermal black, is a hydrocarbon compound with a small, round molecule which is both darker and more likely to migrate under the skin—hence the appearance of some very old tattoos which have lost their sharp lines. Iron-oxide black, generally used for permanent makeup, has a larger, flat-sided molecule which is less likely to migrate, though it doesn’t appear quite as dark. One solution for darker blacks is to add a blue compound (copper pthalocyanine blue)—hence the bluish appearance of some very old tattoos. I sometimes use a little purple to create the blackest eyeliners for my clients who request them, but most eyeliners are a very dark brown with a drop of black added.
This information is courtesy of the Society of Permanent Cosmetic Professionals (SPCP). Please visit www.spcp.org for additional information.
