This is a standard Weld dye, with lye added.
4 gal lye water (10 ph, made from homemade hardwood ash lye)
1 lb weld (Prairie Fibers)
1/2 lb wool fabric
4 oz. alum
Boil wool in alum mordant. Soak for 24 hours, and rinse.
Boil the weld in the 4 gal lye-water for 20 minutes. Strain.
Bring back to a boil. Enter the mordanted wool and stir for 20 minutes.
I tried the lye after reading Carolyn Priest-Dorman's excellent article on period weld dyeing, and the warming effect of lye on the weld. Her findings in the same article that tartar dulled weld made me decide against tartar for this recipe. I could not believe my eyes! This is the sunniest weld I've ever gotten. I need to test different mordant times and alum amounts on the same proportion of weld to wool to lye.
Kremer weld sucks. Prairie Fibers weld is much better, though more expensive. Kremer includes instructions for pre-soaking it in an acidic bath for 24 hours beforehand to get the color out, as it's "Anatolian weld". This should not be necessary, and is in fact counterproductive when an alkaline bath is needed. I've heard rumours that it's not true weld at all. I won't use it again.
2.Weld over-dyed with 2 oz brazilwood dyebath for 30 seconds
3.Weld over-dyed with 2 oz brazilwood dyebath for 5 mins