500g of Sodium Sulphate Anhydrous. This is more effective than the hydrated form of the chemical, commonly known as Glauber’s salt, containing 65% combined water. As a result you will require 2½ times the weight of Glauber’s salt in the dye bath compared with the weight of anhydrous salt, Sodium Sulphate. Sodium Sulphate Anhydrous helps with the levelling of acid dyes, providing an even coverage. Make into a stock solution at 10% concentration (i.e. 10g per 100ml water) allowing 100ml stock solution for every 100g dry fibre weight.