Human hair. Coloured scanning electron micrograph (SEM) of hair shafts growing from the surface of human skin. The shafts of hair (red) are anchored in their individual hair follicles (not seen) below the surface of the skin. Hair is made up of a fibrous protein called keratin. The outer skin layer, the stratum corneum, consists of dead keratinized cells that detach from the body giving this flaky appearance. Magnification: x140 when printed 10cm high.