Alum Mordant Solution for Tannin-Treated Plant Fiber

An alum mordant solution can be used on tannin-treated plant fiber before, after or during the dye process to create a brighter color.

| December 2013

Dyed Plant Fibers

For a quicker, more energy-efficient method of dyeing and mordanting, you can extract the dye and then add the mordant to the dye bath before adding your fiber.

Photo by Fotolia/recklessdaughter

Home dyeing can be a gamble if you are new to the idea, but even if you are experienced in the art, knowing the different reactions given by plant based fibers and animal fibers can be crucial to proper dye absorption. Using The Handbook of Natural Plant Dyes (Timber Press, 2010) Sasha Duerr walks you through using mordants and natural dyes in perfect harmony. Get brighter results with the alum mordant solution featured in this excerpt.


Alum Mordant Solution

After processing your plant fiber with a tannin bath before dyeing, you may want to use alum as an additional mordant to make your color even brighter. When you have rinsed the fiber of tannin, you can apply an alum premordant once, or twice for even brighter results from your dye. Wear gloves when putting your hands in the alum solution. You can save the leftover alum mordant for later use in a sealed, labeled jar. You can also use iron as an additional mordant after using tannin on your fiber, which will make your dye color darker.

4 ounces (113 g) plant fiber
20 percent (4 teaspoons) alum per fiber weight
6 percent (1 1/2 teaspoons) washing soda per fiber weight

Soak fiber in water for at least 1 hour, or overnight.

After mordanting the fiber in tannin solution and rinsing, hang it to drip while you make the alum mordant solution.

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