MORDANT MONDAY: Can A Cold Water Mordant Deepen Colors?

Three red and pink skeins of yarn on a marble background.

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 some aluminum triformate from you all.  I tried the aluminum triformate using it at 10% WOF hoping to get the strongest results possible. So far I have only the aluminum sulfate to compare it to.  It seems the aluminum sulfate samples are much darker, especially the reds, although I am not finished with all the colors.  

I am wondering if this is typically the case? Is there anything you would suggest to coax a darker color? It is most noticeable on the madder and cochineal samples although madder in the aluminum triformate, while lighter, I think is a different red than the aluminum sulfate madder sample and quite gorgeous.

KATHY ANSWERED: We’ve been using the mordant bucket method of aluminum trifomate, which is 20 grams mordant per liter of water.  In a 10 liter container, this turns out to be 200 grams and we were able to use the mordant bath about 8 times before we recharged it with a small amount of mordant and water.

Aluminum trifomate definitely gives very rich tones when used at this concentration and method. The other thing we discovered with this cold mordant bucket technique is that 3 hours soak in the mordant bath gave us a pale shade, but overnight in the mordant bath gave us a very dark shade. It was also important to rinse the mordanted skein of yarn before dyeing, otherwise we ended up with a lighter shade – almost like it inhibited the color a little.

You might still get some very nice colors at 10% wof, but we found that it takes longer as a cold water mordant and we’re suggesting it as a way to put some skeins in the mordant bucket, come back the next morning, rinse, and proceed to dyeing. One of the comments we’ve received is that the customer’s wool is much softer now that she’s not using aluminum sulfate and has switched to aluminum triformate. She was very happy with the product.

I hope that helps you clarify the results you are seeing. The color results are pretty dramatic with the triformate depending on the percentage used and the length of time in the mordant bath, and whether or not you rinse. We tested with cochineal, madder and fustic. 

4 thoughts on “MORDANT MONDAY: Can A Cold Water Mordant Deepen Colors?”

  1. I just want to confirm the math…2 g per 1 liter, shouldn’t it then be 20 g per 10 liters? I’m intrigued with the process and the results, just want to use the correct amount. And for 10 liters, about how much many grams would recharge it? Thanks for this and all the mordant questions you answer/

    • Right, it should be 20 grams per liter and 200 for a 10 liter container. Apologies for the typo. When I recharged, I actually only recharged with 20 grams of aluminum triformate. I was able to dye a few more times with the same dye strength results, so possibly a stronger recharge (like 60 or 100 grams) would last longer. I haven’t explored that yet.

  2. Would this be the same if you were using cotton fabric? I bought some and the first time I used it, I didn’t see any different results. So maybe doing the same with an overnight soak would help cotton fabric?

    • Hi Deb, cotton would definitely benefit from an overnight soak, then a rinse before dyeing. We found that a 3 hour soak in the triformate mordant bucket yielded pale results but saw much richer shades with an overnight soak.

Comments are closed.