Cellulose (hemp, linen, cotton):
Cotton and other cellulose fibers naturally contain pectins, waxes and fatty substances as a product of their growth cycle. These will deflect, mottle and interrupt your mordant print, yielding inconsistent results and a cloudy background print.

Machine: warm water (no hot or kill enzymes), extra water cycle
1.) 1/4 Cup Diastatic Malt “Dry Malt” powder
Dried, crushed barley, dextrose and flour. The powder is enzyme rich. These enzymes begin to digest the pectins and waxes in the fiber. Run the laundry cycle and then walk away, allowing the goods to spin and drain, leaving the damp laundry in a basket for 12–24 hours. Enzymes eat!

2.) Second laundry cycle using 1 cup Soda Ash and HOT water. For best results, if time allows, boil/simmer in pot for 4 hours.

Protein (wool, silk):
WOOL
180F—don’t agitate, agitation causes felting
Hold at 180F for 1 hour, allow to cool 24–48 hours
Rinse, dye
12–20% WOF aluminum potassium sulfate
Using 10% to start, 400g fabric = 40g alum
For 20%, double 40g, so 80g or do 60g for 15%

Can add a “modifier” for brighter colors to alum bath: Cream of Tartar 1tsp per 100g wool
400g fabric, 4 teaspoons = 1tbsp + 1 tsp
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SILK
Maiwa: I have always mordanted silk hot (160F), but The Art and Science of Natural Dyes says that heat mordanting can be damaging, so I now mordant cold using cold water from the tap.