Impushana yombala we-indigo ekhishwe emaqabungeni e-Indigofera tinctoria noma e-Isatis tinctoria (i-woad) ngokuvutshelwa nangokwehlangana nomoya-mpilo. Umbala oluhlaza okwesibhakabhaka uvela ku-indigotin (C16H10N2O2). Kumele wehliswe ngekhemikhali (ebhavini ye-alkali) ukuze uncibilike ukwazi ukudaya — indlela eyehlisiwe iluhlaza okotshani okuphuzi bese iphenduka ibe luhlaza okwesibhakabhaka lapho ihlangana nomoya.