Sodium carbonate (also referred to as ‘soda ash’) is used in dyeing for the following purposes:

• Scouring cotton and cellulose fibres
• As a fixer for cellulose (plant) fibres and silk with fibre reactive (procion mx) dyes
• As an alkaline colour modifier in natural dyeing
• As an alkali in the indigo and woad (vat dyeing) process

Sodium carbonate is also referred to as soda ash and is similar to washing soda crystals.