1A vs 1B Hair: Straight Types Compared

Straight hair is not one-size-fits-all. Moving from 1A to 1B adds body and slightly changes how oil and heat styling show up.

1A strands are typically the finest in the entire twelve-type chart. They struggle to hold heat-set curls and can look oily quickly because sebum travels unobstructed down the hair shaft.

1B adds medium thickness and enough structure that ends may hold a bend from a round brush longer than 1A. You still will not see natural S-waves, but ponytails and braids may feel fuller.

Dry shampoo and root volume techniques matter more for 1A; 1B may tolerate richer conditioners on mid-lengths if ends feel dry from heat styling.

If your hair is straight but you are unsure whether it is “too fine” for 1B, compare how it reacts to a light mousse on damp hair—1A collapses easily under product weight, while 1B can sometimes handle light stylers without going limp.