What does it mean for hair to be porous?

When hair is described as porous, it indicates that it has the ability to absorb liquid. This characteristic arises from the structure of the hair's cuticle, which can be more raised or damaged in porous hair, allowing for easier penetration of moisture and products. High porosity can occur due to various factors, such as chemical treatments, heat styling, or environmental damage, resulting in a cuticle layer that does not lie flat.

While options like being strong and healthy, having high moisture content, or being damaged and brittle relate to the condition of the hair, they do not define what porosity means. Porosity specifically refers to the hair's ability to take in and hold moisture or products, which is a crucial aspect to consider in hair care and treatment regimens. Understanding this property helps haircolorists in selecting appropriate products and techniques for different hair types.