MORDANT MONDAY: Does Alum Triformate Shift Color?

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 just recently tried Alum triformate, first time using it. Have you had reports that it shifts the colors? We used Sequoia extract that was purchased from Maiwa, and it should have a dusty brownish purple, and it did on the regular alum mordanted bits I had in there- but it made a greenish grey on the triformate. Just wondering if you had info on this? I’m going to do a test with 2 skeins in the same dye bath with the different mordants for curiosity sake. Thanks!

KATHY ANSWERED: Thanks for emailing. My tests were not scientific but I did notice the following when I dyed 12 rounds of wool yarn and cotton fabric using the mordant bucket method.  I was trying to determine when I needed to recharge the bucket.

• Rinse the fibers after removing them from the mordant.  I would say triformate is more acidic than aluminum sulfate and any excess unattached mordant or mordant liquid can cause a color shift in the dye bath.
• Mordant for at least 8 hours (I do this overnight) or the color will be lighter.  In the cold method, the mordant needs time to bond. I was able to get very deep and rich red shades using madder and aluminum triformate, soaked overnight and rinsed.
• If you have a pH sensitive dye (many of them are) you may want to modify your dye bath with a slight alkali shift or the addition of chalk to bloom the color.  The sequoia result sounds like a little soda ash might have darkened the shade.  Alternatively, you can soak your skein in a slightly alkaline post bath (pH 8) of soda ash and see what the effect of the color shift is.

YOU ASKED: I have been using soy milk as a mordant for paper because I was afraid alum would degrade the paper too much. Perhaps this is an irrational fear. Any thoughts or resource suggestions for mordants, paper, and natural dyes?

KATHY ANSWERED: I don’t work with paper and don’t have much experience if different mordants affect the paper quality. Soy would act as a binder and impart a different finish than alum, and maybe that is the effect that you want for your work? Perhaps someone from the community has information about preferred mordants for paper.

YOU ASKED: How effective are plant mordants vs metals?

KATHY ANSWERED: I’m assuming that you are speaking about tannins as mordants and how they compare to metallic salts as mordants on cellulose fibers. Tannins can certainly act alone as a mordant and it is possible to get good results and there are numerous historical examples of using tannin alone on cotton. However, tannin by itself is less stable than an aluminum mordant and the tannin can shift color. This is not a bad effect, but it is a feature of some tannins. Interestingly, a tannin pre-treat and aluminum mordant on cotton yields excellent results and is superior to tannin mordant alone or alum mordant alone. This is the mordant method we use most when we need to impart the most light and washfastness on cellulose fibers.