Oxazines

thumb|400px|The 8 isomers of oxazine

thumb|White wool yarn dyed with "orchella weeds", using traditional Natural dye|plant dye methods. Orcein, also called archil, orchil, lacmus and C.I. Natural Red 28 - CICN 758600, is any dye extracted from several species of lichen, commonly known as "orchella weeds", found in various parts of the world. A major source is the archil lichen, Roccella tinctoria. Orcinol is extracted from such lichens. It is then converted to orcein by ammonia and air. In traditional dye-making methods, urine was used as the ammonia source. If the conversion is carried out in the presence of potassium carbonate,