Resistant hair has what level of porosity?

Resistant hair is characterized by low porosity. This means that the hair cuticle layers are tightly packed and overlap each other more significantly, which makes it harder for moisture and chemicals to penetrate the hair shaft. As a result, resistant hair tends to repel water and other products, requiring more effort or the use of specific techniques to achieve effective treatment or styling.

In contrast, hair with medium porosity has a more balanced cuticle structure, allowing for some absorption of moisture and product, while high porosity hair has widely spaced cuticles that easily absorb moisture but can lead to quick loss of that moisture. Variable porosity refers to hair that has different porosity levels along its length, which is not a characteristic of resistant hair. Understanding porosity levels is crucial for selecting the appropriate hair care products and procedures tailored to specific hair types.