Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by function]
6. additive (material)

Anotations

Scope note:

Chemical additives that are part of the dyeing process that allow the dyeing to be carried out more effectively. These may include reducing agents for dyeing with vat dyes or that improve the level of dyeing, better fastness, or other aspects of the dyeing.