1.) Low porosity - doesn't easily allow moisture to be absorbed into hair shaft. harder for water to saturate when it's washed.
a.) low porosity hair pre-poo before shampoo.
b.) wash your hair weekly or bi-weekly will keep it from build up giving opportunity to absorb moisture.
c.) moisturize your hair mid week, cover your hair.
2.) Medium porosity - the least amount maintenance, allows just the right amount of moisture to enter, while preventing too much escaping.
a.) holds styles well, and can be colored and permed with predictable results.
b.) occasional deep condition treatment with protein conditioner, but protein should not be use in daily regimen.
3.) High porosity - absorb too much moisture, and lose easily.
a.) high porosity can be inherent or a result from damage from chemical processing, rough treatment or environmental damage.
b.) prone to frizz, and tangle in humid weather. shampoo, swimming can create damage and breakage due to the sheer amount of moisture.
c.) it's important to use a leave in conditioner, moisturizers and sealers.