Which hair color services usually require strand tests?

Strand tests are critical in assessing how a particular hair color service will interact with a client's hair. These tests help determine the hair's reaction to the chemicals used, which is especially important for services that involve strong chemical processes.

Chemical hair relaxers and permanent color can significantly alter the hair's structure and color, and different hair types react differently to these products. Conducting a strand test prior to applying these treatments can prevent damage and ensure optimal results. By applying the product to a small section of hair, the stylist can observe how the hair responds in terms of texture, color penetration, and any potential adverse reactions. This testing process is vital for maintaining hair integrity and achieving the desired outcome safely.

In contrast, the other options typically involve less drastic changes or are unlikely to cause significant reactions, making strand tests less essential. For example, semi-permanent colors may not require strand tests because they generally don’t penetrate the hair shaft as deeply as permanent colors. Highlights often involve a foiling technique that can be assessed through client consultation rather than needing an in-depth strand test. Additionally, root touch-ups and gloss treatments tend to affect smaller areas and do not usually require strand tests since they are applied to already processed hair. Shampooing and conditioning treatments are