Hair type classification is well described in the this article. Below is the excerpt.
Please note that when I say ‘curly’ hair in this blog, I include type 2 to type 4. The styling method that are described in the blog are also used for wavy and kinky hair type.
TYPE 1: Straight – Hair that reflects the most sheen. It is also the most resilient hair of all of the hair types. It is hard to damage and next to impossible to curl this hair texture. Because the sebum (natural oil produced in the sebaceous glands of the scalp) gently works its way from the scalp to the ends without the interference of curls or kinks, it is the most oily hair texture of all.
Type 1a – Straight (Fine/Thin) – Hair tends to be very Soft, Shiny, difficult to hold a curl, hair also tends to be oily, and difficult to damage.
Type 1b- Straight (Medium) – Hair has lots of volume & body.
Type 1c – Straight (Coarse) – Hair is normally bone straight and difficult to Curl. Asian women usually fall into this category.
TYPE 2: Wavy – Hair that lies somewhere between straight and curly hair. It also imparts sheen, more than curly hair, but less than straight hair. The further down the wavy spectrum you go the less sheen the hair will impart. Wavy hair is typically more prone to frizz. While type A waves can easily alternate between straight and curly styles, type B and C Wavy hair is resistant to styling.
Type 2a – Wavy (Fine/Thin) – Hair has a definite “S” pattern. This type normally can accomplish various styles.
Type 2b – Wavy (Medium) – Hair tends to be frizzy, and a little resistant to styling.
Type 2c – Wavy (Coarse) – Hair is also resistant to styling and normally very frizzy; tends to have thicker waves.
TYPE 3: Curly – Pulling a strand of a type 3 curly, you will notice it has a definite S shape. Granted, the S may be a lower case s or upper case S, or it may even resemble a Z on some occasions…however, there is a definite curl pattern in place, with our without products. This hair type is full bodied, climate dependent (humidity = frizz), and damage prone. Lack of proper care renders dull curls
Type 3a – Curly (Loose Curls) – Hair tends to have a combination texture. It can be thick & full with lots of body, with a definite “S” pattern. It also tends to be frizzy.
Type 3b – Curly (Tight Curls) – Also tends to have a combination texture, with a medium amount of curl.
Type 3c – Tight curls or coils that looks like corkscrews
Type 4: Kinky – Despite many misconceptions, this tightly coiled hair is quite fine and fragile. It is wiry, and delicate by nature. Each strand usually has a zig zag pattern. Kinky hair is the driest hair type, thus it is more prone to breakage and requires a gentle touch. A misconception exists that this hair type does not grow. Kinky hair grows at the same rate as other texture; however, if not treated properly it breaks more than other textures. Treat this hair type like a fine silk blouse – cleanse gently, detangle softly, and avoid harsh chemicals.
Type 4a – Kinky (Soft) – Hair tends to be very Fragile, tightly coiled, and has a more defined curly pattern.
Type 4b – Kinky (Wiry) – Also very fragile and tightly coiled; however with a less visible curl patternType 4c – ‘Z’ pattern hair