bluing (EN)
noun

This word can also be a form of:
blue (verb)

noun “bluing”

sg. bluing, blueing, pl. bluings, blueings or uncountable
  1. a substance added to laundry to make clothes appear whiter
    To keep my white shirts looking bright, I add a bit of bluing to the wash cycle.
  2. methods used to coat steel to prevent it from rusting
    The blacksmith explained that bluing the steel would help prevent it from rusting over time.