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 have been contacting a well-published natural dyer and they say that the aluminum mordants will be washed out of the fiber without pre-treatment with tannin. Do you have any theory why the triformate is able to mordant without a tannin ?
Have you got any data on the wash and light fastness of the triformate on cotton?
KATHY ANSWERED: Alum on cellulose performs better with a tannin pre-treatment. However, we have not noticed that the mordant is washed out of the fiber as we are still able to get good color with alum on cellulose without tannin. If the alum were completely unbonded, we would get no color at all.
My experience with triformate is that it works well with wool as a cold water mordant, but it also works with cotton and linen fibers. We are using triformate mostly as a cold water wool mordant. For cellulose mordanting we use aluminum acetate following the instructions on our how-to page.
YOU ASKED: With this cold water alum, do you also use tannin on cellulose; or is it now a one step process? Let me know! Was at a workshop with Katrina Rodabaugh today and a few of us were discussing it!
KATHY ANSWERED: We’re fans of the tannin pre-treat, then any alum mordant for cellulose. We consistently get richer results, which can sometimes be tricky with cellulose fibers.