Partial hair system

A hair system that typically only covers the top of one’s head, such as is needed for pattern baldness. Can also be limited to smaller/other areas of the head.


The underside edge, roughly one inch deep, bordering the base of a hair system. Typically this is where the user places tape or liquid adhesive, or where a poly perimeter is applied.

Poly perimeter

A thin, pliable strip of polyurethane applied to the full or partial perimeter of a hair system. Adhesives are applied directly to the poly perimeter instead of the hair system base material. It is used to increase durability and simplify cleanup.


The thickness of the edge of a hair system base or hairpiece tape.