What does the term "porosity" refer to in hair?

Porosity in hair refers specifically to the hair's ability to absorb moisture. This characteristic is determined by the condition of the hair cuticle, which is the outermost layer of the hair strand. The cuticle can be more or less tightly packed, affecting how easily moisture can enter or escape the hair shaft.

Hair with high porosity has gaps or holes in the cuticle, making it more susceptible to absorbing moisture but also losing it quickly. This can lead to frizz and damage, as the hair is unable to retain moisture effectively. Conversely, hair with low porosity has a tightly packed cuticle that repels moisture, making it more challenging for products to penetrate.

Understanding porosity is crucial for hair care, as different porosity levels require different products and care methods to maintain optimal hair health. Recognizing how porosity affects moisture retention helps stylists and individuals choose appropriate treatments, conditioners, and styling products that suit specific hair types.