Which factor helps determine the appropriate perm solution and processing time?

• A. Porosity
• B. Hair Length
• C. Hair Color
• D. Curl Pattern

Answer: (A)

Porosity tells you how easily the hair can take in the perm solution, which directly affects how long the chemical needs to work and how strong the solution should be. If hair is highly porous, the solution penetrates quickly, so processing time should be shorter to avoid overprocessing. If hair has low porosity, the cuticle is tighter and the solution penetrates more slowly, so you need more processing time (or a slightly stronger solution) to achieve the desired curl. This is why porosity is the deciding factor for selecting the perm solution and timing. Hair length, color, and curl pattern may affect other aspects of the service, but they don’t determine the processing duration or solution strength as directly as porosity does.