Hair type system
A way of sorting hair by curl pattern, from type 1 straight to type 4 coily, with letters A to C.
Also: curl type, hair typing
A hair typing system groups hair by the shape of the strand. The best known, set out by the American hairstylist Andre Walker in the 1990s and widened since, runs from type 1 straight, through type 2 wavy and type 3 curly, to type 4 coily. Letters A, B and C mark looser to tighter patterns within each type. One head often carries more than one type. It is a styling shorthand, not a science, and it says nothing about thickness, porosity or density.