Which factor related to hair is affected by the condition of the cuticle layer?

The condition of the cuticle layer significantly affects the porosity level of the hair. The cuticle is the outermost layer of the hair shaft and consists of overlapping, scale-like cells. Its integrity determines how well the hair retains moisture and how porous it is.

When the cuticle is healthy and intact, the hair tends to be less porous, meaning it can hold moisture and oils more effectively. Conversely, if the cuticle is damaged or lifted, which can occur from over-processing or environmental factors, the hair becomes more porous. This increased porosity means that the hair can absorb moisture more easily, but it can also lead to moisture loss, making the hair more susceptible to damage.

Understanding hair porosity is crucial for selecting appropriate products and treatments, as high porosity hair may require different care than hair with normal or low porosity.