Henna Black Powder: Indigo (Indigofera tinctoria; Qing Dai) 1 lb

This is Starwest's nitrogen-flushed double wall silverfoil pack. This raw indigo powder is bright green not blue-black. Green indigo produces an intense deep blue color only when properly processed. Proper use of indigo is quite time-consuming requiring considerable technique including fermentation. Indigo (Indigofera tinctoria) has long been one of the most important dyestuffs; this dye was used as far back as 6000 years in China. Dye is obtained from the processing of the plant's green leaves. They are soaked in water and fermented in order to convert the glycoside indican naturally present in the plant to the blue dye indigotin. The precipitate from the fermented leaf solution is mixed with a strong base such as lye pressed into cakes dried and powdered. The powder is then mixed with various other substances to produce different shades of blue and purple. The preparation of natural indigo is carried out as follows: the plant is cut down steeped in vats for about 12 hours and the extract which is of a greenish colour is separated and run into fresh vats. Then it is stirred vigorously so as to bring it into contact with atmospheric oxygen. Insoluble indigo is precipitated as a blue mud which is collected pressed dried and cut into cubes. The blue dyestuff is produced during fermentation of the leaves commonly with caustic soda or sodium hydrosulfite. A paste that exudes from fermenting plant material is processed into cakes and finely ground. The blue color develops as the material is exposed to air. The indigo dye is a derivative of indican a natural constituent of several of the Indigofera species. Indican is enzymatically converted to blue indigotin. The colorfast dye is mixed with different mordants and other plant materials to produce a wide range of colorants. Indigo dyeing and the cultivation on the plant originated in India. Because of the good quality of the dye indigo became an important item of trade between India and other parts of the world by 300 B.C. Dyers in Europe tried to resist the importation of indigo into Europe and were able to do so for a long time. Finally however quality won out. Indigo was an early crop in colonial South Carolina. South Carolina indigo was considered excellent but as the economics were not too good it was replaced by rice. The leaves contain about 3% indigo. Synthetic indigo was produced in 1897. Although indigo of commerce came from an Old World plant another species of Indigofera was domesticated and used as a source of a blue dye by the Precolumbian inhabitants of Yucatan. As a medicinal plant indigo has been used as an emetic. The Chinese use Indigofera tinctoria L. to clean the liver detoxify the blood reduce inflammation alleviate pain and reduce fever. Based on its traditional use for liver problems researchers have investigated whether indigo might protect the liver against chemically induced injury. Animal studies do suggest that extracts of the indigo species Indigofera tinctoria protect the liver from damage by toxic chemicals. No human trials however have been performed to examine indigo's effects on the liver. The indigo species Indigofera tinctoria has a history of use in traditional medical systems and is regarded by herbalists as safe other than the occasional allergic reactions that have been reported. However comprehensive safety tests have not been performed. For this reason indigo should not be used by pregnant or nursing women young children or individuals with severe liver or kidney disease. Safety in other individuals is unknown. Grieve's classic 'A Modern Herbal': 'A blue dyestuff is obtained from the various species of Indigofera. It does not exist ready formed but is produced during fermentation from another agent existing in the plant. This is called Indocan and is yellow amorphous of a nauseous bitter taste with an acid reaction; readily soluble in water alcohol and ether.' 'Medicinal Action and Uses: Indigo was at one time much used in medicine but now is rarely employed. It is said to produce nausea and vomiting.' 'It is a very well-known and highly important dye millions of pounds being exported from India annually.'