What is the purpose of strand testing before a chemical texture service?

• A. To determine final color shade.
• B. To gauge porosity only.
• C. To gauge processing time and chemical strength.
• D. To check for allergies.

Answer: (C)

Strand testing is about predicting how the client's hair will react to the chemical processing. By applying the product to a small, representative strand, you observe how the hair responds over time—how quickly it lifts or loosens, and what processing time is needed to reach the desired result. This directly tells you the appropriate processing time and the strength of the chemical to use for that individual’s hair. If the strand over-processes or shows too much lift too quickly, you know to shorten the time or weaken the solution; if it under-processes, you adjust the time or strength accordingly. This helps prevent damage and ensures the final texture matches the goal. The other ideas aren’t the primary purpose: determining final color shade is separate, porosity assessment is useful but doesn’t specify timing and strength on the hair, and allergy testing is done with a patch test, not a strand test.