WHAT IS HAIR POROSITY?*
Porosity refers to the ability of your hair to absorb moisture and is determined by the state of the hair cuticle. Porosity is a highly important factor in determining curly hair care since moisture is what shapes and defines our curls.
Low porosity is when the cuticle of the hair shaft is too compact and does not permit moisture to enter or leave the hair shaft. Hair with low porosity has a tendency to repel product rather than absorb it.
With normal porosity, the cuticle is compact and inhibits moisture from leaving or entering the hair shaft; however, it will readily absorb and retain product properly formulated for this hair type.
Hair with high porosity, also known as “overly porous” hair, has an open cuticle that both absorbs and releases moisture easily. Although overly porous hair absorbs product quickly, it is often dry, as the open cuticle does not allow for product retention within the hair shaft.
STRAND TEST – TO DETERMINE HAIR POROSITY
With one hand, grasp a hair strand firmly between your fingers. With the other hand, slide the thumb and index fingers from end to scalp. If your fingers “catch” going up the strand, or feel like they are ruffling up the hair strand, your hair is overly porous. If it is smooth, you have normal porosity. If your fingers move very fast up the hair strand and it feels exceptionally slick, you have low porosity.
*The above information is summarized from Live Curly Live Free website