Porous or non-porous hair ? This will help you understand you hair´s behaviour and what kind of treatments it will best respond to.
What is hair porousity? It is a way to describe how the hair scales life. If the hair scales lie flat then the hair is low porousity. If they scales stand away, the hair is porous.
Highly porous hairPorous hair means hair that has gaps and holes in its shaft --- either dues to genetics, or damage. It easily absorbs a lot of water (this leads to frizz and breakage), and easily looses even more water (this leads to dryness). This kind of hair usually likes protein. Emollients (like natural oils) and slightly acidic rinses seal the scales shut.
Non-porous hairNon-porous hair has very tightly-bound scales, with no gaps. This kind of hair doesn´t like protein, since protein weights it down and makes it feel like straw. If non-porous hair gets dry, it´s hard to get the moisture in --- usually some heat is required to get the scales to open (think warm oil or shower cap)
Hair Porosity Tests:
The most reliable way to test porousity is under a microscope, if you have access to one. If not, there are a couple of tests that can help you determine your hairs porousity. The hair on different parts of the head often has different porosity. Test hair from the front hairline, in front of ears, and near the crown:
The finger test:Run a single hair between thumb and ring finger (this finger is more sensitive than the index finger). If the hair feels uneven, knobbly and bumpy then it´s porous. Non-porous hair feels smooth.
Reverse finger test:Hold a hair end firmly. With the other hand, run fingers from end to scalp. When the hair ruffles, and its is difficult to slide the fingers, then the hair is porous.
The water test:Put a strand of hair in a bowl of water. The sooner it sinks, the more porous it is. Very porous hair sinks in under a minute. Non-porous hair will float. Update: this method is ureliable, since hair is usually coated with natural oils and other stuff that might make it float (or sink).
The theories method:
There are certain theories about which types of hair are more porous than others.
Chances that your hair is non-porous if:
* It´s very shiny
* It repels water
* It is straight
* Is difficult to perm or colour.
Chances that your hair is porous if:
* It is curly
* It's always dry
* Holds styles well
* It gets frizzy and soaks water fast
* It is damaged
* It is often blow-dried, hot-curled, straightened, permed, bleached, dyed chemically, etc.
* It is easy to dye, but the colous gets washed out quicker.
Medium porosity is the best, of course. Knowing how porous your hair is makes it easier to pick the right care regimen and products that work with your hair and not against it.
Coming up: what to do about very porous hair