Porosity is the set of voids (pores) in a solid material, these voids are filled by fluids (liquid or gas). It translates into the hair's ability to absorb and retain hydration.
I assure you, hair is by nature porous. Hair is permeable, so it lets water through and can absorb up to 30% of its weight.
The porosity level may vary due to 2 factors:
- hair type : curly, frizzy, frizzy, straight
- external aggressions : discoloration, coloring, smoothing, use of plates, etc.
We can distinguish 3 levels of porosity:
- weak: the hair is not very porous, this means that the hair cuticle has closed scales, that it breathes poorly and therefore that water has difficulty penetrating it.
- medium: moderately porous hair has scales in good condition. They are healthy, easily absorb and retain hydration
- high: a hair with high porosity will result in brittle, dry hair, because its scales will be too open, which will prevent good hydration which lasts.
Okay, but how do I determine the porosity level of my hair?
As a reminder, hair is made up of the hair shaft itself made up of 3 layers:
What interests us here to determine the level of porosity is the cuticle. It is by the appearance of the cuticle that we can see whether the hair is in good or bad health.
With low porosity hair , there is not enough space between these scales, water cannot penetrate. Likewise, none of your treatments to moisturize and nourish the hair are absorbed. Generally, low porosity hair is associated with genetic factors. Low hair porosity is not the reason for the use of chemical treatments or heat.
Generally speaking, straight hair (not bleached) is less porous and absorbs rich treatments less easily. Frizzy and curly hair is more porous and therefore absorbs richer treatments better.
How to see it?
Don't do the glass of water test that you see everywhere. It is not at all reliable, especially because of the material deposits on the hair (care, conditioner, etc.).
It is easier to notice it yourself, for example, does your hair dry with difficulty? Do they swell when humid? When you apply a treatment, does the hair absorb it easily or does it remain greasy?
Why is determining them important?
To better understand your needs and spend your money on products that suit you!
Low porosity hair : Healthy hair maintains a balance between hydration and proteins. Choose your conditioner or conditioning mask while avoiding excess proteins, which would tend to accumulate on the surface, making the hair dry and dull, contrary to the desired moisturizing effect.
To allow the penetration of the active ingredients in your treatments and to hydrate them, you must encourage the opening of the scales. Choose clarifying shampoo once a month . And wash your hair with hot water . When you do a treatment, use heating caps to open the scales.
Favor, in your conditioner, formulas rich in emollients, such as vegetable butters (Shea, Avocado) and botanical oils (Argan, Avocado, Coco, Jojoba, Grape Seed, Baobab). For serums: choose a light formula, without proteins, to attract and retain hydration (glycerin, honey, etc.) and a fluid texture, milk for example.
Hair with high porosity : rely on protein-based treatments. For example, you can add an egg to your Ayurvedic powder mask. Favor rinsing with cider vinegar and cold water at the end of your conditioner.