Ethnolichenology - Lichens For Dye

Lichens For Dye

Lichens are a common source of natural dyes. The lichen dye is usually extracted by either boiling water or ammonia fermentation. Although usually called ammonia fermentation, this method is not actually a fermentation and involves letting the lichen steep in ammonia (traditionally urine) for at least two to three weeks.

In North America the most significant lichen dye is Letharia vulpina. Indigenous people through most of this lichen's range in North America traditionally make a yellow dye from this lichen by boiling it in water.

Historically, traditional dyes in Scotland were very important. Brown lichen dyes (called crottle) and red lichen dyes (called corkir) were used extensively to produce tartans.

Purple dyes from lichens were historically very important throughout Europe from the 15th to 17th centuries. They were generally extracted from Roccella spp. lichens imported from the Canary Islands, Cape Verde Islands, Madagascar, or India. These lichens, and the dye extracted from them, are called orchil (variants archil, orchilla). The same dye was also produced from Ochrolechia spp. lichens in Britain and was called cudbear. Both Roccella spp. and Ochrolechia spp. contain the lichen substance orcin, which converts into the purple dye orcein in the ammonia fermentation process.

Litmus, a water soluble pH indicator dye mixture is also extracted from Roccella species.