What is the purpose of using test strands in the context of lightening services?

• A. To determine if client is allergic.
• B. To predict lift and shade, minimize damage, and adjust formula timing and processing.
• C. To ensure color washes out.
• D. To serve as a fashion statement.

Answer: (B)

Test strands preview how hair will lift and what shade will result, letting you tailor the formula and timing to the client's hair. By applying lightener to a small, representative strand, you can see the actual level of lift you’ll achieve and the resulting tone, which helps you plan the final result accurately. This preview also shows how the hair responds to processing—taking into account factors like porosity and existing color—so you can adjust the developer strength, mix, and processing time to minimize damage and avoid uneven results. While patch testing for allergies is a separate safety step, the strand test’s main purpose is to predict lift and shade, and to fine-tune the processing to protect the integrity of the hair.