Hair that is naturally porous or hair that damaged by bleaching, permanent waving, sunlight or mechanical damage is more “wet-able” and the hold-providing polymers in styling products spread better and even penetrate very slightly into the hair (through the porosity in the cuticle). More product in an evenly distributed layer, grabbing hold even under the surface, means better hold.

People with undamaged hair can improve product hold by removing as much water as possible from hair before styling, and by ensuring that products are applied evenly and distributed thoroughly.