Hair porosity is the ability of the hair to absorb moisture. The degree of porosity is directly related to the condition of the hair cuticle.
Healthy hair with tight-fitting scales of the cuticle layer is resistant to the penetration of any chemicals and is called hydrophobic (moisture repellent). The surface of such hair is smooth, reflects light, and shines. In porous hair, on the other hand, the cuticle layer is raised or completely absent, the coat is matte and readily absorbs moisture, and is considered hydrophilic (absorbs moisture).
There are three types of hair by porosity:
Hair with low porosity is considered healthy and resistant to chemical attack. As a rule, hair is gleaming, especially if it is dark in color. If you try to wet your hair, it repels moisture. Hair with this porosity is challenging to handle as it resists the penetration of chemicals. On such hair, preparations with a more alkaline pH, heat, or longer processing times are used. Alkaline preparations raise the cuticle layer, allow the practices to penetrate and work evenly inside the hair. The heat also speeds up the penetration of drugs into the hair. However, in some cases, this is not enough, and you have to pre-treat the hair to open the cuticle layer.
Hair with low porosity tends to accumulate protein-rich hair care on its surface. This makes this type of hair stiff, like straw, and heavy. Therefore, in caring for such hair, it is essential to use very light cosmetics with moisturizing components (such as glycerin and propylene glycol) that are practically protein-free, so that this care does not settle on the surface of the hair and does not make them oily. For deeper penetration of the treatment into the hair, you can also warm it up slightly immediately after applying the mask or conditioner.
Medium (normal) porosity hair:
Medium porosity hair is normal. Their cuticle layer is slightly loose and allows retaining only the necessary amount of moisture in the hair. That is, on the one hand, it prevents its intense evaporation, and on the other hand, a substantial accumulation of water in the hair. These hairs tend to hold the style well, chemically curl and color with predictable results. They do not require special procedures and solutions. For a given degree of porosity, standard formulations, techniques, and processing times are sufficient. However, over time, these hairdressing treatments damage the hair and increase its porosity.
Hair with medium porosity can occasionally be treated with deep penetrating medicated conditioners with proteins that provide tangible benefits. However, protein should not be found in large amounts in daily hair care formulations, as it can also cause cumulative adverse effects.
Highly porous hair is considered super absorbent, and this quality of hair is usually the result of previous chemical treatments, high-temperature exposure, lack of proper care, environmental damage, or an intrinsic property of the hair (such as curly hair). Porous hair – damaged hair or very frizzy hair – dry, brittle, and brittle. They have lesions or large holes in the cuticle that allow too much moisture to evaporate and make them prone to frizz, also in wet weather. Even simple activities such as bathing, swimming, and shampooing can cause even more damage to the hair due to the enormous amount of moisture that can be absorbed by highly porous hair.
These hairs are treated with preparations with a lower alkali content – low pH to prevent further damage, and select care products are used to regulate porosity before hairdressing. These products do not 100% eliminate the problem of porosity, but they partially fill the voids in the hair and prevent the rapid absorption of dyes and curling compounds. Since porous hair quickly absorbs all preparations, the processing time is therefore short. However, the effects of any procedure do not last long (the color is washed soon out, and the curls are straightened).
In caring for such hair, it is imperative to use superior products (mainly silicone-based) that prevent moisture from absorbing into such hair. This is especially important in climates with high temperatures and humidity. This will help seal the damaged cuticle and prevent porous hair from absorbing excess moisture from the air.
Due to its high porosity, this type of hair can also quickly lose moisture, so it is essential to use leave-in conditioners and moisturizing treatments. These products will help maintain the moisture level in your hair. You can also use a protein-rich revitalizing treatment to provide a “cure” to help fill in the damage in the cuticle layer and further protect your hair from losing more moisture.
The features of the structure (thickness) of the hair can be associated mainly with porosity. For example, thick, healthy Asian hair usually has low porosity and is challenging to treat chemically. However, it’s worth noting that this is just a healthy hair trend. Hair of the same Asians fades in the sun, is lightened by hairdressers, and is not always kept in shape by professional care. As a result, they are damaged and have high porosity, regardless of the cause of its appearance. Therefore, it is essential to understand the trends in hair characteristics associated with ethnicity, but at the same time, take into account merely the human factor. Therefore, it is essential to determine the porosity of the hair to choose the right preparations for the subsequent procedure.
To determine the porosity of the hair, strands are selected in different areas of the head. One-handed hair is supported. On the other hand, the thumb and forefinger are combed from the ends to the scalp. This procedure is carried out exclusively on dry hair.
On hair with low porosity, fingers glide smoothly, and the strand does not comb. Hair with medium porosity is easy to comb, but the fingers feel rough. In the case where a strand is very easy to comb and difficult to comb, even with a comb, the hair is considered very porous and damaged.
Alternative methods for determining hair porosity
There are also methods for determining the porosity of the hair, based on the absorption of water by the hair:
Water is sprayed onto dry hair, and the absorption of drops is observed within 1 minute. If the water is immediately absorbed, then the hair is considered porous, if after a while, it is absorbed, then normal. If the water is not soaked for a long time – more than 1 minute, but the hair is considered closed.
Please take a few hairs and place them in a tall glass of water with warm water (not cold and not hot). In this case, 1 minute is recorded, and it is tracked how quickly the hair got water and drowned. Hair with low porosity is slightly submerged in water or remains on the surface for 1 minute or even longer (30 minutes in the video). Hair with medium porosity sinks slowly, and the longer it falls, the tighter the scales are closed. Porous hair immediately picks up water and sinks.