New York State Cosmetology Practice Exam 2025 – The All-in-One Guide to Master Your Certification!

Coarse hair is more resistant to chemical services due to its thicker and denser structure. The cuticle, which is the outer layer of the hair shaft, is usually more tightly packed and more robust in coarse hair. This characteristic makes it less porous and less susceptible to absorbing chemicals quickly, which means that chemical treatments, such as coloring or perming, may require more time or stronger formulations to effectively penetrate and alter the hair's structure.

When dealing with chemical processes, understanding hair porosity is crucial. Fine hair tends to be more porous and can absorb chemicals more readily, leading to quicker reactions during treatments. Medium hair sits between the two in terms of resistance and porosity. Wavy hair does not inherently indicate a specific level of resistance to chemical treatments; wave patterns can occur in hair of various thicknesses and porosities. Therefore, when considering the resistance of hair to chemical services, coarse hair stands out as the type that is traditionally more resistant.