Porosity is the measure of the hairs ability to absorb moisture. To better understand hair porosity, think of your hair strand as the roof of a house and the outer layer or the cuticle as the shingles on the roof. When the shingles lay completely flat, it’s difficult for water to enter or exit the hair shaft – this is low porosity hair. If the shingles are completely raised then moisture will easily enter and escape – this is high porosity hair. In normal porosity hair, the shingles or cuticles are neither completely flat nor raised, but at an optimum angle to allow moisture to enter and remain there.
Knowing your hair porosity is far more important than knowing your curl pattern since it will greatly affect your ability to have moisturized healthy looking hair.
For those with low hair porosity, it is imperative that you use lighter more liquid based products that will not just sit on top of your hair making it oily or greasy. Also, you will be able to get away with fewer moisturizing sessions to avoid build up.
However, with high hair porosity that easily loses moisture, layering on products to retain moisture is a necessity. Many high porosity naturals, after washing their hair, apply a leave-in conditioner, then a thick water based moisturizer followed by a heavy butter. By layering your products, you are providing your hair with the moisture it needs from the leave-in and moisturizer, and ensuring that the moisture remains near the hair shaft by using a heavy butter or oil to act as a protective layer to prevent the moisture from being lost to the atmosphere. High porosity naturals may also find it necessary to moisturize often and some high porosity naturals moisturize once or twice daily.
If you have normal porosity hair then count your blessings, listen to your hair’s needs and moisturize accordingly.
Read more, to learn how to test your hair’s porosity levels.