PSI Cosmetology Practice Exam

For what reason should a strand test be performed?

1. To determine hair density

2. To see the hair color

3. To assess the hair's porosity

4. To determine the type of shampoo that is best for the hair

The correct answer is: To assess the hair's porosity

A strand test is performed primarily to assess the hair's porosity and overall condition, as this directly influences how the hair will absorb products, particularly color and chemical treatments. Porosity refers to the hair's ability to absorb and retain moisture, which can vary significantly between individuals and even within different sections of the same person's hair. Understanding the porosity of the hair helps professionals predict how the hair will react to various products. For instance, highly porous hair may absorb color more quickly, leading to a different final result compared to hair with normal or low porosity. This is essential for ensuring that the desired outcomes, especially in chemical processes like coloring, perming, or relaxing, are achieved safely and effectively. While determining hair density, assessing hair color, and identifying the best type of shampoo are important aspects of hair care, they do not specifically address the need for a strand test in the context of chemical services. A strand test's primary focus is on the condition and characteristics of the hair itself, particularly in relation to its porosity.