Porosity is defined as the hair's what?

• A. Density
• B. Elasticity
• C. Length
• D. Ability to absorb moisture

Answer: (D)

Porosity measures how easily the hair can take in moisture and chemical products, which depends on the openness of the cuticle. The best answer is that porosity is the hair's ability to absorb moisture. When the cuticle is more open or damaged, moisture enters quickly and can also escape quickly, leading to quick absorption but potential moisture loss and frizz. When the cuticle is tightly packed, absorption is slower and moisture can be harder to penetrate. Density refers to how much hair is on the head, elasticity describes how well hair stretches and returns, and length is how long the hair strand is.