Soda ash (sodium carbonate) is used in natural dyeing as a fixer and scouring agent. In small amounts it can change the pH of a madder dyebath, which makes it redden, and it is used for scouring cellulose fibers. It is also an easy way to raise the pH of an indigo vat: for balancing an indigo vat, plan on 250-500 g (8-16 oz) of soda ash. As a mild base, it adds alkalinity to a dyebath to modify its shade.
Available sizes
50 g (1.76 oz), 100 g (3.5 oz) and 400 g (14.1 oz).
