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. natural dye
10. vegetable dye

Anotations

Scope note:

A natural dye that is bright red to rich purple color, obtained from any of several lichens; used as a pigment, textile dye, wood stain, food colorant, and an indicator dye that turns blue in alkaline solutions. It was by the ancient Egyptians; the preparation was rediscovered by the Italians and used to make the brilliant red and purple Florentine cloth. In the18th century a Scottish chemist C. Gordon patented the process, which he called "cudbear." The dark red color in archil is formed when lecanoric acid is converted to orcein by fermentation then oxidation.