Porosity is a measure of how easily water and other substances can enter and exit the hair strand. Low porosity hair is hydrophobic, which means it repels water from the surface. This type of hair results in flat, tightly sealed cuticles that is more resistant to moisture loss and absorption. Knowing your hair’s porosity will help you make better product purchasing decisions and adjust your regimen accordingly.
To determine your porosity, gently pull a strand of your hair (maybe more strands if you have multiple textures) and drop it in a glass of water. If it floats to the top then you have low porosity curls, if it sinks to the bottom of the glass then you have high porosity hair and if it stays in the middle then your hair is considered regular.
If you have low porosity hair, check out these techniques for getting moisture into your strands: