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.

This is a normal sponge. It absorbs and lets go of water at a normal rate.
This 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.
This 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.