Hair porosity determines how much water can absorb through the cuticle layer of hair. Hair cuticles overlap one another like scales on a fish. The number of gaps between the cuticles varies, depending on the porosity of the hair.
The more breaks in the hair shaft, the more water that can diffuse through these gaps. Curlier hair has more breaks in the shaft, and thus has a higher porosity. Straighter hair has flatter cuticles and therefore has a lower porosity.
Knowing the porosity of your hair can help you choose the right products and treatments for hair. Plus, it will help you have a better understanding of how these products affect your hair. Genetics plays a primary role in what type of porosity your hair is. Yet, changes in your curl pattern can change the porosity of the hair.
Here are the three types of hair porosity and how you can test the porosity of your hair.
Types of Hair Porosity
High porosity hair has many gaps on the surface of the hair shaft. Due to the open cuticles, the hair can absorb up to 55% of water and take on higher concentrations of hair dye. It is commonly found in curlier hair types and hair that has been chemically damaged by dyes, relaxers, heat, et cetera. These factors cause hair strands to lose their structure.
Hair may be dull and brittle, which can cause frizz on humid days. Frizz occurs when hair cuticles search for moisture in the hair. When products are applied to the hair, the hair cannot retain the moisture for very long. As a result, this type of hair requires constant moisture. Plus, emollients and anti-humectants can prevent excessive absorption from the humidity by sealing cuticles.
It can also become knotted and unruly very quickly since the open cuticles can get tangled onto other hair strands. Not to mention, it loses elasticity due to the weight of the water that it absorbs.
Medium porosity hair has tiny open gaps in the hair cuticle. It can absorb about 31% of the water that passes through the cortex of each hair strand.
Hair with this porosity is usually healthy, requires the least amount of maintenance, and holds hairstyles well. It is ideal to deep condition this type of hair with protein products occasionally.
However, chemically altering the hair will ultimately cause its porosity to increase over time.
Low porosity hair contains tightly bound cuticles, which makes it difficult for water to diffuse through. After applying products to the hair, the moisture sits on top of it. This is what causes low porosity hair to be shiny, which looks more apparent in darker hair. This is also why it takes a long time for hair to dry and for styles to hold.
Protein products should be used sparingly to avoid accumulation on the hair. Since the cuticles layer one another, protein and other nutrients are hard to process and penetrate. This could cause the hair to feel stiff.
This porosity is healthy, but only when the cuticles are opened for moisture. For best results, deep condition the hair and add moderate heat. Humectants and emollients are ideal for attracting moisture.
Hair Porosity Test
Before you test your hair, wash your hair so that it is devoid of product and oil. Then, place a strand of your hair in a glass of water.
- Low porosity hair floats. Only a small percentage of water is absorbed.
- Medium porosity hair stays in the middle. It can only retain an adequate percentage of the water.
- High porosity hair sinks toward the bottom of the glass. It absorbs a large amount of water.
Each hair porosity has its challenges, and that is why it is crucial to reevaluate your hair regime. What changes have you made since you discovered the porosity of your hair? Tell us in the comments below!