Understanding Porosity When Searching for Hair Products

(photo by koalie)

Understanding hair porosity was probably one of the biggest things that helped me find the right hair care products for my daughter. And I can't say it was an easy process. I knew that my hair was pretty porous (colouring for years has turned it into a fly-away mess when the weather is dry), but I wasn't really sure about my daughter's hair. I had some idea that it would swell a bit in our humid weather, but only when using certain products. She never had the same fly-away problems that I did when it was dry outside and it took a bit of research before I actually understood why. And now that I know, I know which products work best on her hair and, better yet, when to use them.

Pores on the hair strand are like fish gills.

What!?! Stay with me, I'm trying to go somewhere with this. Reading through a ton of jargon about how a strand of hair works can be a bit overwhelming. Couple the jargon with scientific drawings and/or microscopic images breaking down the different elements of a hair shaft can further complicate things. That is, if you're not a total science nerd such as myself (I love this stuff by the way!). So I decided to break it down like I would if I were explaining it to my daughter (or even my husband, for that matter), because eventually I'm going to have to. Fish gills were the simplest way that I could think to describe pores on the hair, especially when we all know what pores on our skin look like. So thinking of pores like fish gills, you can see that the hair needs them to "breathe" and stay healthy. If they are too open, they let too much in and out; if they're too closed, they suffocate and die.

Healthy hair has pores that lay mostly flat and smooth. If you lay a fish flat, the gills lay flat against it. The water that's in the hair doesn't get out very easily; the water outside of the hair can get it, but also not very easily. It's a pretty balanced system. The hair looks and feels smoother because, well, the gills, er uh, pores, are laying flat. So if you have really healthy hair and then start dumping a bunch of product on it, it would be like sealing the fish's gills closed; it wouldn't be able to breathe. Same concept.

Damaged hair has pores where the flaps are not laying flat, they're sticking out, leaving gaping holes. When that happens water can get in really easily. Sounds great, right? Well it's not, because it gets out just as easily. And that's how porous hair dries out so quickly.

Now think of curly hair. Fish are straight and the gills are designed to lay flat when the fish flat. When you bend the fish along the gills, you can see how they flap open more than they do when the fish is flat. Get where I'm going here? If you imagine a strand of hair covered with those gills, and then you put all these kinks and bends in it, many of the pores would flapping open. The curlier the hair, the more likely the pores are not going to be laying nice and flat because, well, the strand upon which the pores are located is not nice and flat.

All curly does not have high porosity.

Curly hair may be more vulnerable to porosity, but it doesn't necessarily mean it's true. There are a ton of different factors that go into this, including genetics. And one of the most important parts of genetics is how much protein the hair has. Some people have more protein in their hair than others. And protein actually forms a shield over the pores, so even if they are flapping up a bit from being attached to a very tightly coiled hair strand, the protein helps control the flow of moisture in and out. Therefore, you could have super kinky-curly hair, but awesome protein and, hence, low porosity. Or you could have super straight hair and low protein and, thus, high porosity. Curl pattern, then, doesn't dictate porosity. Hence knowing whether or not child has Type 4b or Type 3a curl pattern isn't going to tell you how porous your child's hair is. So picking products based solely on curl pattern is not the best way to go. In short, don't buy the same products as someone else just because you both have the same curl pattern.

What causes high porosity.

Genetics doesn't (usually) cause highly porous hair. Damage does. Suffice it to say that heat (ironing and blow drying), colouring (which is not as bad as it used to be), and chemical processing like perms relaxers can all damage the hair. Some of these processes specifically affect the protective protein, some can literally damage the strand of hair, itself, especially if done frequently and/or over long periods of time. Damage can also be caused by over-manipulation, such as rubber band usage, rough brushing/detangling, and/or using products that are drying and/or damaging.

Testing hair porosity is pretty easy.

I was really pleased with this test over at The Beauty Brains. If you're interested in testing the porosity of your child's hair, it's also a fun experiment to do with him or her. If you're not interested in going through the trouble, the easiest observations are to see how much the hair swells without any product in it when it's humid. If your child's hair gets really big and twist-outs are suddenly afros when it's humid outside, it's pretty porous. If humidity doesn't seem to affect the hair at all, then it's not very porous. I say to test it without product because many of the products that we use are humectants, which draw moisture out of the environment and into the hair, so using products will obviously skew results.
Also, when it's dry outside, does the hair get really light and fly-away? Mine does, like crazy! That's when I start dipping into Boo's coconut oil for my ends. Boo's hair shrinks when it's dry, but doesn't become brittle or fly-away like mine does. Without product she retains more water in her hair than I do.

Choose products for hair needs, not curl pattern.

So, this is what it all boils down to: If your child's hair is porous, he or she will likely need to have some products that will both draw in moisture (humectants) as well as seal it in once it's there. See our post on moisture, butters, and oils to get a better idea of which to use and when. Damaged hair might also benefit from protein treatments to help replenish the protein in their hair to help protect it better. Protein rich products and conditioners can be used daily, or as a pre-poo or deep condition. Sadly, if the hair has been damaged to the point where it is extremely porous (i.e., it sinks right away during the porosity test outlined above), there is nothing you can do to repair it. The damage is permanent and although products can help seal in moisture, the pores will never lay flat again on their own. Any claims that products can "fix damaged hair" in this regard are false.

Porous hair can also benefit from an apple cider vinegar (ACV) rinse. Unlike using ACV to cleanse the hair, sealing the cuticle with ACV is done after a wash and condition, before styling. The acidity of the ACV will encourage the layers of the cuticle to flatten a bit, thus leaving the strand less prone to loss of moisture. Because my hair is more porous than my daughter's, I will actually use ACV for a cuticle-sealing rinse, whereas with her we will use it as a clarifying wash to break through product build-up.

For as long as this post was, this was actually the short version. There is a great deal of science behind how hair and products work together, and porosity is just one of many elements that needs to be taken into account while searching for the right hair care regime for your child. Other things such as styling habits (including protective styling), how hard your child plays, how well the hair is protected while sleeping, and what the weather is like all play a role, as does protein (which I touched on a bit above) and nutrition. Healthy hair really does come from the inside out, so making sure your child is well hydrated and eating balanced meals will help immensely, especially if you've recently brought your child home and their previous environment did not provide adequate nutrition.