Hair Typing 101
Texture
Hair texture describes the thickness of your individual hair strands - Fine, Normal, and (or) Coarse. Both Fine and (most) Normal strands contain just 2 layers - the Cortex and the Cuticle. Coarse strands contain all 3 - Cortext, Cuticle, and Medulla. The medulla is mostly just empty space and proteins.
Fine hair is silkier to the touch, and may not hold styles very well. You also may also have trouble feeling a single strand rubbed between your fingers. Finer hair is more delicate given its smaller protein content, and heavy products will weigh it down. Check out Fine Natural Hair Rocks for great tips on how to maintain fine strands. For your protein treatments, you may benefit from targeting larger protein sources (oat, wheat, soy, and quinoa for example).
Normal (medium) strands can feel silky to the touch as well, but less so. When held between your fingers, you can feel them, but not particularly well. It is less fragile than fine hair, but would still be vulnerable to heat styling. Be sure to take proper precautions when using heat (as should all textures). These strands should hold styles relatively well, and your hair will look full and cover your whole scalp in its healthier state. For your protein treatments, you may benefit from targeting larger protein sources (oat, wheat, soy, and quinoa, for example).
Coarse strands feel more substantial, are less delicate, are also more visible to the eyes when held up to the light. Coarse hair can also better tolerate heat and chemicals (but don’t abuse either!). These strands will hold styles best. These strands have a tendency to look dull and lack shine, so finding the right products to boost these characteristics will be a task (check out the product finder on this website!). Regarding protein treatments, you may benefit from targeting smaller protein sources (amino acids, peptides and hydrolyzed proteins (silk, oat, keratin, collagen, etc).
Density
Density measures how densely packed the hair follicles on your scalp are, and therefore how many strands are on your head. The average person has ~2200 strands per square inch. Examine your hair in its clean (no-product), dry state and natural shape to observe your density.
Low density - If in its natural state described above, you can easily see your scalp, you have low density hair. To avoid weighing down your hair, try using lighter products. Mousse can help give the appearance of volume, as can curlier styles.
Medium density - If in its natural state as described above, you can see some of your scalp, you have medium density hair. It should be easier to style this hair, and you can benefit from both heavier and lighter products. Wash and go’s, braid outs, rod sets, and twist outs are all great styles for this density of hair.
High density - In its natural state as described above, it is either difficult or impossible to see your scalp. You may benefit from choosing heavier products (butters, creams, gels) to help clump your curls, and to reduce volume (or go ahead and let that flag run free!)
Porosity
Hair porosity measures the ability of your hair strands to take in, retain, and to expel water, based on the structure of your hair cuticle layer.
Low porosity
The cuticles lay flat, making it harder for water and other products to penetrate the strands. Per the science, as difficult as it is for moisture to enter the strands, it is just as difficult for it to escape, meaning that low porosity hair should better retain moisture. In my experience, that has not been the case. My hair is prone to dryness, and until I repaired my hair through proper treatment over time, it had never held moisture despite my low porosity strands. Applying heat helps open the cuticles for treatments to penetrate, and steam treatments are specifically recommended. I won’t go into preferred product consistencies, and “to use”, or “not to use” oils because in my experience, it really depends on the hair, and is not necessarily tied to porosity. Product consistency is more relevant to density, and fine vs coarse as described in previous sections. Note that there may be oils better for low porosity or high porosity hair. See the 2 “Manifest” oil formulations from Beau Peep Luxuries.
Low porosity tests
A clean and virgin strand of hair (no product applied) will sit on top of a cup of water even after 5 minutes. This indicates that the hair strand is not absorbing water which would otherwise weigh it down.
When you wet your hair, you see water bubbles sitting on top of your strands instead of penetrating.
When you slide your fingers up the hair shaft, it will feel very smooth.
Normal (Medium) Porosity
The hair cuticles are not fully open, and not fully closed, and this should be the most amenable porosity level. Your hair does a good job of taking in, and retaining moisture.
Normal porosity tests
A clean and virgin strand of hair (no product applied) will sink partially in a cup of water within 5 minutes.
When you wet your hair, the water bubbles will slowly penetrate your strands and you won’t see as much sitting on top of your hair as if you were low porosity
When you slide your fingers up the hair shaft, you can feel little granules of an open cuticle on your fingers
High porosity
The cuticles are largely open, making it easy for water and other products to enter to and to leave the strands, and it is hard to keep the strands moisturized. You can develop high porosity hair through chemical treatments (relaxers, chemical hair dying, etc), or you can have this porosity naturally. I won’t go into the preferred product consistencies, and to use, or not to use, oils because in my experience, and having spoken to many naturals, it really depends on the hair, and is not necessarily tied to porosity. Product consistency is more relevant to density and fine vs coarse as described in previous sections. Note there may be oils better for low porosity or high porosity hair. See the 2 Manifest oil formulations from Beau Peep Luxuries.
High porosity tests
A clean and virgin strand of hair (no product applied) will sink to the bottom of a cup of water within 5 minutes. This indicates that the hair strand is absorbing water and weighing it down.
When you wet your hair, the water will quickly penetrate the strand instead of sitting on top as a water bubble.
When you slide your fingers up the hair shaft, it feels very rough.
Elasticity
Elasticity measures the extent to which you can stretch your hair, and it will return to its normal un-stretched state. Healthier hair will have higher elasticity, but this will be in the range determined partially by the hair’s density (higher density strands tend to be more elastic, lower density tends to be less elastic).
To keep your ideal amount of elasticity, you will need to maintain a good moisture/protein balance. Too much moisture can make the hair gummy, leading to hygral fatigue, and too much protein can make the hair stiff and fragile.