Simmering Dye Mordant is used to dye clothes and is made by adding alum to simmering water. To use, you dip wool clothes in to make them "dye ready", then dip them in either Simmering Rose Madder Dye or Simmering Indigo Dye. It will turn into ashes with bowl after 2 minutes.
Note: White Apron does not need to be pre-treated and can be directly placed into the rose madder dye.