Which type of hair is considered the most porous when undergoing chemical relaxing?

The most porous type of hair when undergoing chemical relaxing is coarse hair. Porosity refers to the hair's ability to absorb moisture, and coarse hair has a larger diameter and more open cuticle layers, which allow it to absorb chemicals and moisture more readily than other hair types.

When performing chemical relaxing, porous hair can process faster because the chemicals penetrate more easily. This can lead to a more rapid and sometimes uneven reaction, emphasizing the need for careful monitoring during the relaxing process. It is crucial for stylists to understand this characteristic so they can adjust timing and application methods accordingly to avoid damage.

In contrast, fine hair typically has a tighter cuticle layer, which makes it less porous and less receptive to chemical treatments, requiring different handling techniques to avoid over-processing. Medium and thick hair also have varying porosity levels, but coarse hair is specifically notable for its higher porosity, making it the right answer to this question.