What type of hair is known to absorb the least amount of moisture?

Hair that is characterized as low porosity has a tightly closed cuticle layer, which means that it does not allow moisture to be absorbed easily. This quality is typically due to the natural structure of the hair shaft, where the cuticle layers are smooth and overlapping, making it difficult for water and other moisturizing products to penetrate. As a result, low porosity hair often requires specific techniques or products, such as heat or lighter oils, to help open up the cuticle and allow moisture to enter.

In contrast, high porosity hair has a more opened cuticle that readily absorbs moisture but can also lead to moisture loss quickly. Medium porosity hair sits in between and usually has a balanced ability to absorb and retain moisture, while very low porosity hair suggests an extreme form of low porosity, but typically the consensus is to categorize it under low porosity. Recognizing the porosity level of hair is essential for determining the best hair care practices and products to use.