Hair porosity: its meaning and how to determine yours for type 4 natural hair

Returning to natural hair means you are introduced to a whole new range of vocabulary and concepts that you’d think you’re studying for a whole new college course. This ranges from learning about the hair type chart and natural hair porosity as well as new hair practices such as pre-pooing and treatments, to the roles of different ingredients and what you allegedly can and can’t put on your hair. All this put together has made maintaining healthy natural hair, including kinky type 4 hair (4a, 4b,4c), seem like a complex mission that is quite overwhelming to get a full grasp of.

Don’t worry yourself though. Type 4 On A Mission is here to help one post at a time!

In this blog post, we will be breaking down the science of hair porosity!

What is hair porosity and why is it important?

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In short, your hair porosity is your natural hair’s ability to take in and retain moisture.

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Our natural hair can do this thanks to our cuticle layer.

To help you remember this, the meaning of hair porosity is in the name… it’s how POROUS the hair is. POROUSity.

These are essentially pores that can open or shut naturally and/or from cues from products or the environment. This opening and closing of the cuticles are how moisture (which is water, read my blog on ingredients if you don’t know this already) enters and remains in our hair. 

This process is called hydration. 

Water enters our hair cuticles when it’s open and lifted, and is sealed in when our cuticles shut. 

The process of dehydration is when water leaves the hair cuticle through the openings.

The different types of hair porosities…

Now that you know the overall basic principles of hair porosity, let’s talk about the different types of hair porosities and which one or ones you can have (because contrary to popular belief you can have more than one hair porosity on your head of hair). 

There are three hair porosities: low porosity, medium porosity and high porosity. Keep in mind that this is a spectrum and no two heads of hair will behave EXACTLY the same. 

In general (and keep in mind this is not always true) hair that is healthy and untreated tends to be lower in porosity. However, this does not mean that you cannot have healthy, natural and untreated hair that is naturally high porosity.

So what differentiates all of them?

Low porosity hair 

This is when the hair cuticles are flat and tightly shut. In this case, the hair cuticles are also harder to open, hence people with low porosity hair find it more difficult to let water inside the hair. However, once she’s in there, she ain’t coming out!

High Porosity Hair

This is when the hair cuticles are highly lifted. So, although water can be easily absorbed by hair strands, it can also easily come straight back out. High porosity hair also tends to be more porous due to missing protein to fill in the cuticle.

Because of this, high porosity natural hair tends to be more dry and brittle if not properly treated and sealed. 

Medium Porosity Hair

Medium porosity hair is in between low and high porosity hair. This is hair that has a balanced of compactly shut and raised cuticles. 

For this reason, medium porosity hair has a natural balance between absorbing sufficient amounts of moisture and keeping it all inside the hair strand. 

People with this hair porosity, therefore, tend to not struggle too much with moisturising their hair if they have a correct routine.

(To see how to build a proper routine to promote moisture check out this blog post on wash day and which products you should be using and how by clicking here).

How to know your hair porosity?

Now that you know the three different hair porosities, you’re probably wondering how you can determine which one you have. 

Before you go looking for any test, the biggest tell of your natural hair porosity is how it behaves in general. You can also look out for certain patterns you may spot in your hair characteristics.

Low porosity

As described above, the cuticles of low-porosity hair are tightly compact so it is harder for moisture to be absorbed. 

Because of this, you may have noticed that your hair takes time to fully saturate itself with water in the shower. You may have also spotted that water forms beads on top of your hair when sprayed with a spray bottle and that products generally sit on top of your hair and form a white visible coat instead of being absorbed. 

These are clear cases that represent how moisture and product are physically getting prevented from being taken into your hair. 

Having tight and compactly shut cuticles gives low porosity natural hair several distinguishing features!

Because the cuticles are tightly shut and compact, low porosity natural hair tends to be shinier since light reflects off the smooth surface to create a natural shine. 

Additionally, this smooth surface means that low porosity hair suffers from less friction between hair strands. As a result, it is less likely to form fairy knots and should be easier to detangle. 

These features are not apparent to every low porosity natural but if you can tick off a lot of these behaviours and characteristics then it’s highly likely that you could have low porosity hair 😉

(Note that because of certain hair practices, experiencing some of these does not mean you have low porosity hair. E.g. If your hair finds it difficult to absorb water it could be because your hair is heavily coated in water-repelling products such as oils, and not because you have low porosity hair. For more detail click here)

High porosity

In high porosity hair, the cuticles are highly raised.

These open cuticles allow for water to easily enter the hair but it can easily escape too.

So characteristics you may observe as a high porosity natural include hair that can rapidly and easily be saturated in water in the shower, hair that air dries quickly after the shower, hair that instantly drinks up any product that you apply and hair that is easily dehydrated.

Because of the raised cuticles other hair characteristics that you may notice include hair that is dull/matte in appearance. You may also observe that your hair is more prone to tangles and fairy knots. This is due to the raised cuticles increasing friction between each curl, kink and coil, increasing the likelihood that they will tangle up.  

Due to the dehydration and lack of protein that fill up the pores, you may also find that your high porosity hair is brittle and more prone to damage.

Don’t worry though!

These issues can be easily resolved with treatments and looking for certain key ingredients in your hair products. 😉

Medium porosity

As a medium porosity natural your hair will mainly behave normally.

Behaving normally means that you don’t have any issues with absorbing moisture or losing it and don’t suffer from any major hair issues. 

You’ve got this easy!

Water cup/float test

Now I’m sure that everyone and their grandma in the natural hair community have heard of this test to identify your hair’s porosity.

Method

1. Fill up a clear cup with filtered water.
2. Get a clean hair strand of yours (e.g. shed hair from a brush). Please don’t pluck out your hair for this!
3. Gently place your hair strand on top of the water. To be as gentle as possible, lightly drop your hair strand into a cup by dropping it from a distance that is just above the rim of the cup.
4. Wait 15 mins and keep the cup still on a level surface.
5. Check the placement of your hair strand.

Low porosity results

If your hair just floats on top of the water, then you could have low porosity hair! 

The hair strand just floats at the top because the hair cuticles are so tightly shut that they don’t let water in. Because no water is going in, then the hair strand simply floats at the top since the water is not weighing it down.

High porosity results

If your hair sinks to the bottom then you could have high porosity hair!

Your hair cuticles are highly raised and porous, so your hair just quickly soaks up all the water that it can, causing it to sink.

Medium porosity results

If your hair strand only sinks to about halfway down the cup then you could have medium porosity hair!

Your hair strand will only sink halfway as it doesn’t absorb as much water as high porosity hair does due to having a balance of open and closed cuticles.

Hair strand test

This is when you grab a hair strand (this time it can be attached to your head) and run two fingers up the hair strand from your ends, up to your roots. 

If your hair feels completely smooth and you encounter no bumps, then you could have low porosity hair. 

If you find a lot of bumps along the way then you could have high porosity hair.

Feeling a mixture of both means you could have medium porosity hair.

Test conclusion for natural hair porosity

You can test out any of these two tests on multiple hair strands to determine the overall porosity of your hair, and see if you have multiple on your head of hair!

Final words

So there you have it!

One natural hair phenomenon made simple 🙂

Make sure to share this with those who are also struggling to get a grasp of their hair and their porosity and need some help!

You will also want to follow up reading this blog post in this natural hair porosity series by reading my next one on the importance of hair porosity and how you should adjust your routine for porosity!

Trust me, you don’t want to miss out on this crucial, hair-saving information 😉

With love,

A type 4 natural ♥