Improves the yield of Turquoise Fiber Reactive Dye. (Gives more intense color). Use in place of,and in the same proportions as, Plain Salt, when dyeing solid shades of #25 Turquoise or colors mixed with #25 (marked with T on the color chart). Also used as a leveling agent for production dyeing with Leveling class Acid Dyes for wool and silk to get the most even results. Approximately 1 1/4 cups per lb, but that can vary based on the density.
Note - this is the anhydrous form of Sodium Sulfate, not the deca-hydrated form. Best for dying as mentioned above, but not usually what you are looking for for science experiments! (we've been asked)