Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by function]
6. colorant (material)
7. dye
8. [dye by composition or origin]
9. synthetic dye

Anotations

Scope note:

Any of a class of wash-fast sulfur-containing synthetic organic dyes dissolved in a heated alkaline bath of sodium sulfide and then absorbed by cellulose fibers to which they are applied; they are made insoluble within the fibers by oxidation upon exposure to air. They are the dyes most commonly used for cotton.