What is porosity?
Porosity refers to how well your hair is able to absorb and hold moisture. It is affected by the flexible outer hair layer called the cuticle, which determines how easily moisture and oils pass in and out of your hair. For most, porosity is genetic, but it can also be affected by external factors such as exposure, heat treatments and chemical processing. Knowing your hair’s porosity can help you choose the right products to keep your hair well-moisturized, supple, strong and shiny.
Different levels of porosity:
Low- has a tightly bound cuticle layer with overlapping scales that lay flat. This type of hair is usually considered healthy, and is often very shiny, especially when it’s dark in color. Hair repels moisture when you try to wet it and is hard to process since it resists penetration of chemicals. It is also prone to build-up from protein-rich deep conditioning products, which can leave it feeling stiff and straw-like. Low porosity hair requires moisturizers rich in emollients such as shea butter, jojoba oil, coconut oil and mineral oil. It also benefits from humectant products, which attract and hold moisture to your hair.
You should: Choose lighter, liquid-based products such as hair milks that won’t sit on your hair and leave it oily or greasy. Stick to protein-free, daily conditioners with humectants such as glycerin or honey. Use moderate heat with protein-free deep conditioning treatments to help open up the tightly bound cuticle.
Medium: Often requires the least amount of maintenance. The cuticle layer is looser, allowing just the right amount of moisture to enter while preventing too much from escaping. Hair with medium porosity tends to hold styles well, and can be permed and colored with predictable results. Over time, however, these processes can damage your hair and increase its porosity.
You should: Occasionally deep condition using treatments with protein conditioners. This can benefit medium porosity hair, but proteins should not be included in your daily regimen.
High: Can be either an inherent property of hair or the result of damage from chemical processing, rough treatment or environmental damage. High porosity hair has gaps and holes in the cuticle, which let too much moisture into your hair and leave it prone to frizz and tangling in humid weather. Even simple acts such as bathing, swimming and shampooing can create more damage and breakage due to the sheer amount of moisture highly porous hair can absorb.
You should: Be sure to use anti-humectants in climates with high heat and humidity. This will help seal your damaged cuticles and prevent them from absorbing excess moisture in the air. Because highly porous hair can also lose moisture easily, it’s important to use leave-in conditioners, moisturizers and sealers. Layering these products will help your hair hold on to the moisture you’re giving it. You can even follow up with a heavy hair butter to help fill the gaps in your damaged cuticles and further protect your hair from losing too much moisture.
Why is Porosity important?
Porosity is a critically important factor in determining one’s hair care. Moisture determines the health of our hair and this is more evident in wavy, curly, kinky or highly textured hair. Because moisture defines and shapes the curls, the inability to absorb or keep moisture in the hair shaft will undermine even the most valiant efforts to maximize our curl potential.
If you don’t know your hair’s porosity, you won’t be able to pick out the best products and maintenance routine choices to maximize the amount of moisture your hair retains. Lack of moisture is one of the biggest causes of frizzy, dry, dull hair.
The texture of your hair is not an indication of its porosity. Different degrees of porosity can be found in all hair textures. For example, although coarse hair normally has a low porosity and is resistant to chemical services, coarse hair can also have high porosity too, either naturally or as the result of damage or previous chemical services.
How does my porosity affect treatments?
Low porosity is known as “resistant” hair, which makes it more difficult to process, it is resistant to chemical services, and has a tendency to repel products rather than absorb them. Chemical services performed on hair with low porosity require a more alkaline solution. This is needed to raise the cuticle and permit uniform saturation and penetration. While hair with low porosity is difficult for chemicals to penetrate and takes a longer processing time, the color will last much longer.
Medium porosity hair, allows for normal processing when a chemical service is performed – according to the texture – and will readily absorb and retain product properly formulated for this hair type.
High porosity is considered “overly porous” & can occur naturally, but is usually the result of previous over processing. Other factors that affect porosity include heat damage, chlorine/hard water/mineral saturation, sun damage, or use of harsh ingredients. Overly porous hair is dry, andfragile. High porosity hair processes very quickly and can be easily damaged even further if extreme care is not taken when a chemical service is performed. Chemical services performed on overly porous hair require more acidic solutions with a lower pH level, which help to prevent further over processing. Although overly porous hair takes color quickly, the color also fades quickly.
How to determine your hair’s porosity:
There are a few methods you can use to find out how porous your hair is.
- The Float Test: Take a couple of strands of hair from your comb or brush and drop them into a bowl of water. Let them sit for 2-4 minutes. If your hair floats, you have low porosity. If it sinks, you have high porosity.
- The Slip’n’Slide Test: Take a strand of hair and slide your fingers up the shaft (toward the scalp). If you feel little bumps along the way, this means that your cuticle is lifted and that you have high porosity. If your fingers slip smoothly, then you have low porosity hair.
- Spray Test: Hold a section of your clean hair that you have washed the night before. Do not blow dry it, as this can cause damage to the hair. Spray the section with a mist of water. Look to see if the hair absorbs the mist. The water should roll off the hair immediately, indicating a non-porous or resistant condition. If it absorbs and disappears, the hair is porous.
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