There are no knots, which can appear as black dots inside the poly skin. Instead of tying in the hair, single hairs are injected by hand into the poly skin, and an extra thin coat of polyurethane is set over the scalp side of the base. Maximum density is about 100% for single injected hair, but we can add some double injections to increase it a bit more.

Until 2007, we stated that this material was too thick to provide a reasonably undetectable front edge, but now it can be made thinner, and looks great at the hairline, even with a combed back hairstyle.