Indigo - Indigofera tinctoria
Indigo is the only natural blue dye used by many cultures in unrelated places on every habited continent. Each culture, each village, and each dyer has a unique way of making the magic of indigo work. There are often rituals surrounding the successful extraction and dye process. Stories unfold about why this vat was successful and another failed. Our natural indigo is indigofera tinctoria, one of the strongest natural indigos, and is finely powdered and easy to use. This particular indigo is ideal for producing greens when overdyed with any of the yellow immersion dyes. You can obtain lime green to forest green depending on the yellow dye used and the number of indigo dips.
Color: Sky Blue to Midnight
Earthues recommends using lye (sodium hydroxide) to dissolve the indigo and thiourea dioxide to reduce (remove the oxygen) for the chemically-reduced vat. Sodium carbonate is then used to raise the pH of the vat as necessary.
There are several natural methods that work well with indigofera tinctoria as well; lime (calcium hydroxide) is used to dissolve the indigo and then fructose sugar, ferrous sulfate, henna, or ripe bananas are used to reduce the vat. Sodium carbonate is used to raise the pH of the vat as necessary.