We have been so lucky to get guest blogger Lucy Lepchani to talk about the use of natural mordants. Mordants are a huge part of determining the colours and final results of your dye projects and if you head over to Lucy’s blog you can see some of the beautiful and varied results she has achieved, check it out here.
“I have stuck with the least toxic and most affordable/accessible ones so far, which are salt, vinegar, tannin from rhubarb/blackberry/oak leaves, alum (bought as a powder) soda ash/washing soda, and iron. Some dyes don’t need mordants: lichens, turmeric and oak.
How I use them: first, make sure the wool is washed of any commercial fastening or detergent. careful not to felt it in the process – heat is OK – agitation makes felt. You can use soda ash but I hate how it makes wool brittle. Iron is my favourite: keep some rusty nails or steel wool in a jar of spirit vinegar. After the wool is washed and rinsed, or, as I do, after the dye is in the pan, add a good sloosh (I am so slapdash, a sloosh is a small wineglass full) of iron mordant and let the wool soak for ages and ages – ages x 2 meaning a few hours or a day.
Using alum must be done in advance – I use it with all kitchen ingredient things (not turmeric) but it must be used in equal parts with cream of tartar or th wool is horribly sticky.
Iron makes colours slightly murky (I love these) alum makes them quite as-they-are, and I hear that tin and copper make the colours brighter but I haven’t made natural versions of them yet. I want to. That will involve copper in vinegar, and tin likewise. Slooshes are my mainstay of amount, I have yet to discover how they work. I have just ordered a teeny amount of copper sulphate to save time/see if its worth the trouble of using copper in my palette. If so, I will be harassing plumbers for their leftovers forever.
Also – vinegar brings out the red in colours, bicarb accentuates blue. With an alum mordant, you can get a range of pinks, mauves and blues from red cabbage. salt is my go-to if I’m having self doubt about a mordant, I just add a teaspoon or so into the mix.