Eyeliner is applied closer to the eye's mucous membrane than any other cosmetic product, yet most formulations still depend on a petroleum-derived pigment classified as a possible human carcinogen.

The beauty industry made do with carbon black for as long as it had to. The formulators who built their careers around it were talented, rigorous, and working with the best available materials. That history deserves respect. But history is also the setup for what comes next.