Hierarchy classification:

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

Additional parents:

1. top of the aat hierarchies
2. Materials Facet
3. Materials
4. materials
5. materials by function
6. colorant
7. dye
8. dye by composition or origin
9. synthetic dye

Anotations

Scope note:

Substances used to optically brighten or whiten materials including textiles and paper, or to give a blue tint to metal, particularly gunmetal. A variety of substances may be used as bluing including many pigments and chemical formulations.