What is the purpose of a porosity test and how does it affect color application?

• A. To measure hair length.
• B. To gauge how open the cuticle is; informs processing time, filler needs, and whether to adjust lift or deposit for even results.
• C. To assess scalp health.
• D. To determine shade.

Answer: (B)

Porosity is about how easily pigment can enter the hair, which depends on how open or closed the cuticle is. The porosity test reveals this openness, telling you how long color should process, whether a filler is needed to even out differences in how the hair takes color, and whether to lean more on lifting or depositing pigment to achieve a uniform result. If the hair is highly porous, it will accept color quickly and can become uneven if not controlled, so you’ll typically shorten processing time, monitor lift, and use a filler to even porosity so deposits are uniform. If the cuticle is less porous, color penetrates slowly, so you may extend processing time, adjust the deposit, or use heat to help penetration, again with a filler to provide an even base for consistent color. This test isn’t about hair length, scalp health, or choosing a shade; it directly guides how color will behave during processing and deposition.