Dye Afterbaths
Afterbaths are useful for expanding the range of dye colors from one dye vat. Yarns can be immersed in afterbaths directly, or soon after they are removed from the dye pot. Preparing the baths is simple, and the results are immediate.
Iron
Iron afterbaths are known to deepen or “dull” dye colors. In the case of staghorn sumac, the color shifts altogether, from chestnut brown to a deep charcoal.
Choose a bowl or pot large enough for your fibers to move freely around the vat. Fill your vessel with the iron solution (add extra water if needed so the fibers can move about freely). Heat the iron solution until it’s just beginning to steam a little (140-160°F). Add the dyed fibers and let sit in the afterbath for approximately 10 minutes. Remove and gently rinse your fibers in warm water after letting them cool for several minutes. Hang fibers to dry after rinsing.
Vinegar
A vinegar afterbath will brighten orange, yellow, and red dyes.
Fill a glass, stainless steel, or enamel vessel with enough hot tap water for your fibers to move freely. Add approximately 1/2 c. of vinegar for every 4 oz. of fiber you are dipping. As an alternative, you can begin with cold water and heat your vessel on the stove until it is hot to the touch. Add vinegar once the water is hot. Transfer fibers to your vinegar solution immediately after removing them from the dye vat. Stir gently and continuously in the solution for up to 10 minutes.
Wood Ash
Wood ash and soda ash can be used interchangeably to create an alkali afterbath. You can simply dissolve 1 tsp. of soda ash for every 4 oz. of fiber into your afterbath dye vessel. Taking wood ash from your fireplace or outdoor fire-pit is a way to make use of an available by-product that does not need to be synthetically produced, as is the case with soda ash.
1. To make the solution, put wood ash into a woven cloth (or fine cheesecloth) bag and hang the bag over a plastic bucket or other available vessel.
2. Fill your container with enough water so that the bag of wood ash is completely immersed. Squeeze the bag for 4 to 5 minutes, and then let it soak for several days, squeezing the wood ash bag twice a day.
3. This wood ash solution can be poured into your afterbath vessel and gently heated until it is hot to the touch. Once your fibers have been removed from the dye vat, they can be placed in the alkali afterbath for approximately 10 minutes.
Read more from Harvesting Color:
How to Make Natural Dyes
How to Make Mordants for Natural Dyes
Master Dye Bath Recipe
Fiber Preparation for Dyeing Yarn
Excerpted from Harvesting Color: How to Find Plants and Make Natural Dyes by Rebecca Burgess (Artisan Books). Copyright © 2011. Photographs by Paige Green.