Oregon Cosmetology Certification Practice Exam

Porosity of hair refers to how well hair absorbs and retains moisture. This is determined by the hair's cuticle, which can either lay flat or be raised, allowing moisture to seep into the hair shaft. This is why high-porosity hair tends to be dry and damaged, while low-porosity hair may have difficulty absorbing products. The other options, such as density, growth direction, and natural color, do not directly relate to porosity and therefore are incorrect.