Soda Ash, also known as sodium carbonate, is a workhorse in the dye studio. It may be used in small amounts to alter the ph of a madder dye bath which causes it to redden, or used for scouring cellulose fibers. It is also an easy way to raise the pH of an indigo vat. In addition, it is a mild base that increases the pH of an indigo vat or adds alkalinity to a dyebath to modify its shade.
- When balancing an indigo vat, plan on using between 250-500 grams (8-16 ounces) of Soda Ash.