• 1 cup vinegar
• steel wool pad

Soak for 4 hours. Strain. Add 1 Tbsp Cream of Tartar

• 3 cups hazelnut hulls
• 1/2 gallon water

Boil for several hours, replenishing water as needed. Strain. Add mordant and fibers.
Boil fibers in dye-bath for 2 hours. Allow fibers to cool in dye-bath before rinsing.