What is Going on Up There

Hair texture usually means the thickness of each individual strand (fine, medium, coarse), but in everyday language people also use it to mean the overall pattern (straight, wavy, curly, coily).

Texture vs type vs other traits

      Texture (strand diameter): Fine, medium, or coarse, referring to how thick each hair strand is.

• Hair type (pattern): Straight , wavy , curly, coily/kinky 
• Other key traits: Porosity (how easily hair absorbs/holds water), density (how many strands per area), and elasticity (how far hair stretches before breaking) all influence behavior but are distinct from texture.

Strand texture: fine, medium, coarse

• Fine: Small diameter, often only cuticle + a small cortex; looks delicate, gets oily and weighed down easily, and is more prone to breakage.
• Medium: “Average” diameter, usually most common; tends to be more resilient, holds styles reasonably well, and isn’t as easily weighed down as fine hair.
• Coarse (thick): Largest diameter, usually a more robust cortex; feels rougher, resists heat and chemicals more, holds styles well, but can be drier and harder to saturate with moisture.

Pattern: straight, wavy, curly, coily

• Straight : No bend or very minimal; sebum travels easily, so it can look shinier and oilier.
• Wavy : “S” pattern along the shaft; tends to frizz in humidity and can be styled straighter or curlier.
• Curly : Distinct loops or spirals; naturally drier because oil has trouble traveling down the curl.
• Coily/Kinky : Very tight coils or zigzags with significant shrinkage; often fine but densely packed and quite fragile despite looking strong.

How the traits interact

• Any pattern can occur with any strand texture, and that combo shapes product and technique choices.
• Porosity and elasticity overlay on top of texture and type, changing how much protein, moisture, and cuticle care a given head of hair can handle.

What porosity means

• Porosity is hair’s ability to absorb and retain moisture, largely controlled by the condition and arrangement of the cuticle layer.
• Levels are usually described as low, medium (normal), and high, and each behaves very differently in water, products, and chemical services.

Low porosity hair

• Cuticles lie very flat and tight, so water and products bead up or sit on top, and it can take a while for hair to get fully saturated.
• Hair often feels smooth and looks shiny, dries slowly, tends to get buildup easily, and can be resistant to color or chemical processing.

Medium (normal) porosity hair

• Cuticles are less tightly packed, allowing moisture to enter at a moderate rate and stay in the fiber without escaping too quickly.
• Hair usually holds styles well, accepts color and treatments predictably, and looks healthy without needing as much “work” as low or high porosity.

High porosity hair

• Cuticles are raised or have gaps (often from genetics, heat, lightener, or chemical damage), so hair soaks up water and product very quickly.
• Moisture also escapes fast, so hair feels dry, frizzy, tangly, air-dries quickly, and is more prone to dullness and breakage.

Hair density

Is the number of hair strands growing in a given area of the scalp, usually described as low, medium, or high density.

In practice, it’s about how closely the follicles (and therefore strands) sit together, which is why it affects how “full” or “thick” someone’s hair looks, regardless of whether each individual strand is fine, medium, or coarse.