The outer cuticle layer of human hair is not smooth-surfaced but scaly in one direction. Hair coloring e.g. it destroys the cuticle layer, and the scales separate from each other, making the hair dull, fragmented, and more prone to tangling. If the wig is made of such hair without sorting the hair direction, it will most likely become unmanageable after a while. Dyed human hair is not used in the hair industry. The hairs from hajadományból, carefully cut hairs are sorted, graded grouped.