What type of hair texture is most resistant to chemical processing?

Coarse hair is most resistant to chemical processing due to its larger diameter and denser structure. The individual strands of coarse hair have a thicker cuticle, which is the outer protective layer. This robust cuticle structure makes it more challenging for chemicals to penetrate deeply into the hair shaft, thereby leading to a greater resistance to processes such as perming, relaxing, or coloring.

In terms of overall chemical treatment, coarse hair generally requires more potent or longer-acting products to achieve the desired result compared to finer or medium-textured hair. Fine hair, on the other hand, is more susceptible to damage from chemicals due to its smaller diameter and fragile cuticle. Medium hair falls in between, but still lacks the resilience found in coarse hair. Curly hair can have varying degrees of texture and may also be resistant depending on its thickness, but coarse hair is notably the most resistant among all types due to the aforementioned characteristics.