Which porosity is described as often being called Resistant?

• A. Low porosity
• B. Resistant
• C. High porosity
• D. Normal porosity

Answer: (B)

Moisture interaction with hair is what’s being tested here. Porosity describes how easily the hair shaft allows water and moisture to penetrate the cuticle. Hair with low porosity has cuticles that lie very flat and tightly packed, forming a strong barrier. Because of this tight seal, moisture and products have a hard time getting in, so this type of hair is often described as resistant to absorption. It can take longer to wet through and may not hold moisture as readily, which is why it often needs methods like gentle heat or lighter formulations to help with penetration. In contrast, high porosity has raised cuticles and so absorbs moisture quickly but also loses it quickly, while normal porosity sits in between with a balanced rate of absorption and retention. So the descriptor most closely associated with resistance to moisture entry is low porosity.