Why is it important to assess hair porosity prior to chemical services?

Assessing hair porosity prior to chemical services is crucial because it directly influences how well the hair can absorb and retain chemical products. Porosity refers to the hair's ability to absorb moisture and other substances, which is determined by the condition and structure of the hair cuticle.

When the cuticle is raised or damaged due to previous chemical treatments, the hair's porosity is considered high. This means that the hair can absorb products quickly, but it may also lead to over-processing, as high porosity hair can lose moisture and nutrients more rapidly. Understanding the porosity allows the stylist to choose the appropriate formulations and application techniques that will deliver the best results while minimizing damage.

In contrast, if the hair has low porosity, it may be resistant to absorbing products, requiring heat or other methods to open the cuticle for effective treatment. Therefore, knowing the porosity helps the cosmetologist tailor the chemical service to the specific needs of the client's hair, ensuring both safety and effectiveness.