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Curly Nikki

SO FINE: Natural Hair Part 3

By January 27th, 202133 Comments
SO FINE: Porosity and Why it Matters
by Cassidy of Natural Selection Blog
“Great, I’ve got fine hair too!! So. Whatproductsdoyouusewhatshouldiuse howshouldistylewhereshouldibuyhowmuchshouldiusecanyou pleasetellmeeverythingineedtoknowaboutfinehairnowwwwww???”

This has been an extremely popular question I’ve been getting in comments and emails since jumping into the So Fine Series to which I can only respond with one thing:

HOLD YOUR HORSES, YOU FINE THANGS YOU! We’ve gotta talk about porosity first.

To all of you whose eyes just glazed over because you get confused about all of this science-y hair stuff, keep reading (and stop pulling at your coils!! Remember: fine hair is fragile!!!). I promise I’m going to make this easy.

What is porosity? Porosity in hair-speak is a way of saying ” a strand’s ability to soak up and let go of moisture.”

While I would love to keep that pantyhose analogy alive, I can’t and we’re going to talk about porosity in terms of SPONGES.

SO FINE: Natural Hair Part 3This is a normal sponge. It absorbs and lets go of water at a normal rate.
SO FINE: Natural Hair Part 3This is a sponge in a plastic bag. If you submerge the bag beneath water, the water will eventually get inside the bag, but it will take longer and more effort to fully soak the sponge. It is also more difficult to get the water out.
SO FINE: Natural Hair Part 3This is a sponge that I took a pair of scissors to. The larger holes in this one mean that water seeps into and squishes out more easily than the above sponges with normal and low porosity.

Now take these same concepts and apply them to your hair.

  • Normal sponge = hair with normal porosity. Moisture goes in and out of hair with relative ease at a neither breakneck nor snails pace.
  • Sponge in plastic bag = hair with low porosity. It takes a lot more work to moisturize this kind of hair because its harder for moisture to get in. But once you get that moisture in, its harder for it to get out.
  • Holey Sponge = hair with high porosity. This kind of hair absorbs – and loses – moisture much more easily. Normal porosity falls somewhere in the middle of these two.

Think of it this way: High porosity = easy in/easy out. Low porosity = difficult to get in/difficult to get out.

How do you figure out what level of porosity you have?

I’ve heard of three methods for figuring out your porosity.

1. 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 it slips smoothly down, then you’re on the lower end of the scale. The

2. The Sink-or-Float Test: Take a strand of hair and place it in a glass of water. If it sinks quickly, its high porosity. If it takes some time to sink, then its normal porosity. If it just stays floating near the top, then its low porosity.

3. Take Out/Order In:
As in take out 20 strands of your hair and order a hair analysis test from Live Curly Live Free. They’ll do a complete analysis of your hair and tell you your porosity (and lots of other fun things) about your hair!

There is no “better” or “worse” porosity because each type has its own unique challenges to work with. The reason knowing porosity is important is because you need to know which type of moisturizer will work best for your hair. Fine hair with high porosity has different moisture needs than fine hair with low porosity. If you end up using the wrong moisturizers for your porosity level, your hair will wind up looking (and feeling) like this type of sponge. And you don’t want that.

SO FINE: Natural Hair Part 3


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  • Michal Booster says:

  • Roman Drama King says:

    super i have seen the same news on the

  • faheem says:

    I read your article. it has helped me a lot to understand the porosity of my hair.Your work is good keep it up as well !I have a question? if i use coconut oil on my hair. so Will it be into absorbed my hair.My hair type is low porosity hair.

  • trayemama says:

    OMG!! I am so thankful that I found this Fine series!! Cassidy, you are a great teacher:) Looking forward to finally learning more about my dense, fine, low porosity hair. I am amazed that my hair is still floating in the water!! As someone else mentioned, it did flips when it touched the water and curled up tight. . .amazing:)

  • Hermione says:

    I have very fine, kinky hair. It's so fine that when I try to wear an afro, the top falls over – it won't stand up. I thought about putting henna in it to thicken it. I just did the strand test and my hair stayed afloat – low porosity. I wear the 2 strand twist out but in the back my ends frizz up fast!! What can I do to stop the frizz and have smooth curly ends? I've started using Avlon butter creme. I need help.

  • Anonymous says:

    Okay so I just did the strand test in the water and both stands just stayed afloat. Now I'm confused because it really doesn't take a lot for me to mositurize my hair. Grant it I do wash and go's daily and I only use condish to leave in and style, I don't use any other products. I'm confused because based on the strand test I have low porosity hair but my hair dries rather quickly during my wash and go's that's why I love them so much and my hair loves the creamy condish's I use.

  • Unknown says:

    Cassidy, THANK YOU sooooo much for this article! I thought I was slow for not understanding articles on porosity:- but I see that I was not alone, LOL. Thanks for making it plain and simple to understand. Based on the description you provided, I figured I had low porous hair but I did the sink or float test last night and it was confirmed that I indeed have low porous hair! Your article was very helpful. Thanks again and I look forward to reading your next article on tips/products for low porous hair.

  • Brittney Desiree says:

    I tried the slip-n-slide method and I have bumps…I also have unique situation where Im growing out hair dye from a year ago. As soon as I dropped it in the water these bubbles formed (could be from product) and in less than a minute the dyed half sunk like a brick while the non-dyed part sank slowly–the whole strand sank vertically. I'm guessing my non-dyed is NP and the dyed is HP. I have 2 types of porosity going on in my strands for sure. I dont know if this is good or bad.

  • Anonymous says:

    Idk if this is a porosity thing, but does anyone elses hair seem to basically detangle itself once water touches it?

  • Anonymous says:

    Low porosity here. But what was really interesting was seeing my hair curl up tight while in the water (had me thinking IT'S ALIVE!)Thanks for sharing! Ang

  • Anonymous says:

    My hair floated in that water cup all day! I've noticed lately that my hair has been oh so dry no matter what I do to it and was thinking of trying an ACV rinse in case the problem was buildup, HOWEVER just saw a thread in the forum where someone said that ACV was bad for LP hair? What should I do then? HELLLPPPPP!

  • Leo the Yardie Chick says:

    So, I napped and just checked it. It's STILL floating, though some portions were under water rather than on top of it. It only sank when I nudged most of it beneath the water's surface.

    So I'm guessing my hair (or at least that strand) is low porosity.

  • melanie says:

    Very informative! Looks like i'm LP. How do you figure out what products work better on LP hair?

  • sarah says:

    @Anon 4.17 that happened to me too. it's perfectly normal to have multiple porosities and textures and curl patterns on one head. or, you can try it again. if on average it stays on top, you have low porosity.

  • Anonymous says:

    For the ladies that did the sink or float test, did anyone else notice bubbles forming all around the strand?

  • Anonymous says:

    SO! I'm at work… bored hahaha. I just cut 2 strands of hair and put it into a glass jar. One strand immediately sunk to the bottom the other strand remains at the top just-a-floatin… :/ I'm confused.

  • Leo the Yardie Chick says:

    I'm performing the glass-of-water test right now. It's been 5 minutes and my hair strand's just floating along without a care.

    I'll give it 15 more minutes and check again.

  • caracara says:

    I have low porosity hair and I found that water just beads up and never absorbs in my hair unless its saturated–like drenched. Another LP characteristic is that it takes forever to dry and sometimes creamy products just sit on top for hours. I use a steamer to help open the hair cuticle and avoid creamy styling products.

  • Anonymous says:

    Brilliant article, always found it difficult to understand porosity but you've made it so easy.

  • Anonymous says:

    My hair starts feeling dry about 5-6 days after an overnight DT with a combination of oils.

    It shrinks A LOT after washing, airdrying and prior to putting on conditioner.

    I guess this qualifies as high porosity?
    It is also rather fine, so if I use heavy creams/ butters, it gets weighed down. Coconut oil gets absorbed well without leaving a greasy feel. The Curls product line seem to be the best overall line for me and it is heavily coconut based.

    What do any of you swear by who have fine, highly porous hair?


  • Sisou says:

    I did the float test a while back and my hair floated forever! Which explains why my hair takes days to dry. Unfortunately, there is not very much information out there on routines for low porosity hair and tricks on maintaining moisture.

  • Jeannette says:

    Great article! Very informative :).

  • Blakbutterfli says:

    Ok @ Cassadie – I can be patient. Hopefully! 🙂

    So, I'm going with low porosity, thin, fine hair that shrinks to almost twa status when wet.

    >>>> Going to the couch to wait on Cassadie's next post…

  • Anonymous says:

    Cassidy, my hair strand stays floating on the top so i'm guessing that's low porosity-BUT my hair shrinks like nobody's biz when it's wet. Doesn't that mean it takes in moisture easily?

    I'm confused because my hair is so hard to moisturize (i dc'd last night, moisturized, sealed etc.) and right now my hair still looks like that last sponge. What moisturizers should low porosity use?

  • cassadie says:

    Hi all—

    YES! You caught a typo. The last sentence should read "If it just stays floating near the top, then its low porosity."

    Fixing it up there riiiight now.

    @Blakbutterfli— yes you have to wait 😉

  • Anonymous says:

    LOL on the last picture! "if you end up using the wrong moisturizers for your porosity level, your hair will wind up looking (and feeling) like this type of sponge. And you don't want that." I hear ya!

  • Courtney says:

    If the hair sinks in the porosity water test, it means it is high porosity (i.e. the hair has easily absorbed the water). If the hair floats at the top, then it is low porosity.

  • Blakbutterfli says:

    Uh-oh – maybe I'm low porosity then since my hair didn't sink at all?

  • Anonymous says:

    oh yep there is a typo. Is sinking quickly low porosity or high?

  • Anonymous says:

    Thx for breaking this down.

  • Blakbutterfli says:

    I am SO very excited about reading this series, as I feel I am cursed (yes, I said it) with fine, extremely soft, low density and – now I know – high porosity hair. 🙂 The few hairs I yanked out of my head never sank in that glass of water – just chilled at the top!

    So, all that being said – I'd love to know the product recommendations for this hair type. Cassidy – do I have to wait for the next posting? 🙂

  • Anonymous says:

    Hello Cassidy, thanks for the wonderful articles! You have provided so much insight – you've helped me to understand my fine, thin, 4c coils! Love ya!! 🙂

    ps. Can you provide a clarification of item 2? The last sentance is contradictory! 🙁

    "2. The Sink-or-Float Test: Take a strand of hair and place it in a glass of water. If it sinks quickly, its high porosity. If it takes some time to sink, then its normal porosity. If it just stays floating near the top, then its high porosity"

    All the best!

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