Hair simulation, scalp pigmentation, or scalp shading are all the same techniques, however, scalp tattooing in not performed in clinical conditions and tattoo inks are used in this technique. Hair simulation, scalp pigmentation, or scalp shading is a procedure that needs to be performed in clinical conditions, and is a medical procedure. In all these techniques, the scalp is pigmented.
One can find powder concealers that one can apply on the scalp to cover it up. These can be purchased, and applied daily, however, these concealers do not stay after shower or swimming. In hair simulations, the inks stay for up to 18-24 months.