The Curl Whisperer on Hair Porosity
There are a lot of myths out there about hair porosity and how it relates to curly hair care and maintenance. Let's see if we can't set some of the record straight.
Porosity is, simply put, the hair's ability to absorb and retain moisture. Porosity is an important factor in determining one's curly hair care. Since moisture is what defines and shapes our curls, the inability to keep moisture within the hair shaft will defeat the most valiant efforts to maximize curl potential.
Your degree of porosity is directly related to the condition of your cuticle layer. Healthy hair with a compact cuticle layer is naturally resistant to penetration. Porous hair has a raised cuticle layer that easily absorbs water, but is quick to lose moisture as well. The texture of your hair is not a definite indication of its porosity, however, nor does your porosity have anything to do with what product/product brand you should use. If you ever want to see me throw the mother of all temper tantrums, go into my Facebook group and introduce yourself by telling us what your porosity is.
Different degrees of porosity can be found in all hair textures. For example, although coarse hair normally can have a low porosity and is resistant to chemical services, coarse hair can also have high porosity as the result of damage or previous chemical services. It isn't a definite thing.
There are three different levels of porosity:
Hair with low porosity is considered "resistant" hair. Low porosity is when the cuticle of the hair shaft is too compact and does not permit moisture to enter or leave the hair shaft. Hair with low porosity is much more difficult to process, is resistant to chemical services, and has a tendency to repel product rather than absorb it. Chemical services performed on hair with low porosity require a more alkaline solution than those on hair with high porosity, to raise the cuticle and permit uniform saturation and penetration.
Hair with average porosity is considered "normal" hair. With normal porosity, the cuticle is compact and inhibits moisture from leaving or entering the hair shaft; however, it 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.
Hair with high porosity is considered "overly porous" and is often the result of previous over-processing. Other factors that can also affect porosity include heat damage, chlorine/hard water/mineral saturation, sun damage, or the use of harsh ingredients such as sulfates. Overly porous hair is damaged in some way, and is dry, fragile and brittle. It has an open cuticle that both absorbs and releases moisture easily; it processes very quickly and can be easily damaged even further if extreme care is not taken when a chemical service is performed. Although overly porous hair absorbs product quickly, it is often dry as the open cuticle does not allow for product retention within the hair shaft. Chemical services performed on overly porous hair require less alkaline solutions with a lower pH, which will help to prevent further over-processing.
Porous hair accepts hair color faster and permits darker color than less porous hair; however, although overly porous hair takes color quickly, color also fades quickly. While hair with low porosity is difficult for chemicals to penetrate and takes a longer processing time, the color will last much longer.
You can check porosity on dry hair by taking a strand of several hairs from four different areas of the head (front hairline, temple, crown and nape). Slide the thumb and index finger of your other hand down each hair strand from end to scalp. If it is smooth, you have normal porosity. If your fingers move very fast up the hair strand and it feels exceptionally slick, dense and hard, you have low porosity. If your fingers "catch" going up the strand, feel like they are ruffling up the hair strand, or if the hair strand breaks, your hair is overly porous.
Unfortunately, porosity issues stemming from irreparable hair damage CANNOT be permanently corrected. Only time can truly mend damaged hair. You can, however, create a temporary fix until the damaged part grows out by "reconstructing" the hair shaft with protein treatments. Protein fills in any holes within the cortex (inner layer of the hair) and also helps to fill in the gaps exposed by a raised cuticle.
Individuals with coarse hair, however, must be cautious: putting additional protein on coarse hair can dry it out even more. For those with a coarse texture, acidic treatments such as apple cider vinegar rinses are likely a better alternative as your hair already manufactures an overabundance of protein naturally.
So, what does this mean for the average girl with curls? It means you need to determine your hair texture and porosity, then think about what type of hair care routine is best suited to your particular hair type. Other factors will come into play, but these two hair properties are the most important properties to know.