We get mordant questions all the time at Botanical Colors so why not create Mordant Monday??? Got mordanting questions? Email [email protected]
YOU ASKED: I recently purchased Ceriops Tagal Liquid Dye and have used it once already, I love it!! I am looking at your site and it says post-mordanting with iron to alter the color but I can’t seem to find what color it will produce. Does it result in a darker almost black shade like walnut would?
KATHY ANSWERED: Ceriops creates a very dark chocolate shade when immersed in an iron rich mud solution (check out this link from Threads of Life). With a ferrous sulfate post bath, it may also make almost a purple-brown as it’s quite reddish.
YOU ASKED: What is your favorite/preferred mordanting process for plant-based and animal-based fabrics?
KATHY ANSWERED: Check out our mordanting instructions. I am partial to aluminum sulfate with or without Cream of Tartar for wool and animal fibers, aluminum sulfate for silk, and aluminum acetate for plant-based fabrics.
In regard to post-mordanting with iron I have done this to shift yellow (weld with alum) to a more green color on wool. I make an iron mordant by taking about half a cup of white vinegar and adding rusty nails to it. After about a day the rusty solution can be diluted (maybe 1:4) with hot water in a container only used for iron solutions. Then I put in the wet and warm wool and let soak for perhaps 20 minutes. Take out the wool, rinse it and let dry.
If a tannin solution (such as boiled oak leaves or twigs) is added to the diluted iron it immediately gives a black precipitate. I haven’t experimented much with this as I’m concerned it would harshen or even weaken the wool but it would be useful for some purposes.