How is hair porosity defined?

Hair porosity refers to the ability of hair to absorb moisture, such as water or oil. It is influenced by the structure of the hair cuticle, which is the outermost layer. When the cuticle is tightly packed, hair has low porosity and is less able to absorb moisture. Conversely, when the cuticle is more open or damaged, hair has high porosity and can absorb moisture more easily, but may also lose it quickly. Understanding hair porosity is essential for selecting appropriate hair care products and treating the hair effectively, as it affects how well products will penetrate and how much moisture the hair retains.

Other definitions provided do not match the definition of hair porosity. The amount of damage in hair relates to its health, the thickness of each strand refers to hair diameter, and the natural color pertains to pigmentation rather than absorption capacity. Thus, the correct understanding of hair porosity distinctly centers around its ability to absorb and retain moisture and oils.