What does the term porosity refer to in hair?

The term porosity in hair refers specifically to the ability of the hair to absorb moisture. This characteristic is crucial in understanding how hair interacts with hair products, treatments, and environmental factors. Hair porosity is determined by the condition of the cuticle, the outer layer of the hair strand.

When hair has high porosity, it means the cuticle is lifted or damaged, which allows moisture to enter easily but also means it can lose moisture just as quickly. Conversely, hair with low porosity has a tightly closed cuticle, making it more resistant to absorbing moisture and requiring more effort to penetrate with products.

Understanding porosity is vital for haircolorists and hairstylists because it influences how treatments are applied and how the hair will react to color and conditioning products. Choosing the appropriate products and techniques based on the hair's porosity ensures optimal results and maintains hair health.