青黛为爵床科植物马蓝Baphicacanthus cusia(Nees) Bremek.蓼科植物蓼蓝polygonum tinctorium Ait和十字花科植物菘蓝Isatisindigotiea Firt等的叶或茎叶经水浸泡二至三昼夜至叶腐烂,茎脱皮时捞去茎枝叶渣,加一定比例的石灰,充分搅拌至浸液由乌绿色转为紫红色时,捞取表面的泡沫状物,干燥而成。但近来发现市售青黛中有不去叶渣,加工后捞取下沉的叶渣及石灰,并 The green barley is a plant of the Acipenser genus Malus Baphicacanthus cusia (Nees) Bremek. The indigo plant Polygonum tinctorium Ait and the crucifer plant Isatisindigotiea Firt are soaked in water for two to three days until the leaves rot. When peeling, remove the stem and leaf residue, add a certain proportion of lime, and stir until the infusion is turned from blackish green to purple red. Then, take the surface of the foam and dry it. However, it has recently been found that commercially available barley have no leaf residue, and after processing, the sinking leaf residue and lime are harvested, and