What characteristic does hair with a compact cuticle layer have concerning chemicals?

Hair with a compact cuticle layer is characterized by its tight and overlapping structure of cuticle cells, which effectively protects the inner layers of the hair shaft. This compact arrangement creates a barrier that minimizes the ability of chemical substances to penetrate the hair. As a result, hair with a compact cuticle layer resists penetration by chemicals.

This resistance is crucial when considering hair treatments such as coloring or chemical relaxers, where the integrity of the hair's structure can influence how well these chemicals can be absorbed and how they interact with the hair. When the cuticle layer is compact, it provides a stronger shield, resulting in a lower rate of absorption for chemicals, thus affecting how hair responds to various treatments.