Dyeing with Alder Leaves & Iron Mordant
Autumn begins early here in the Pacific Northwest, slowly creeping into August with cooler evenings and falling leaves. Already, the clouds have returned, bringing small rain falls and relieving us from the haze of wild fires that burn to the north and east of the mountains.
Walking by the wetlands last week, I noticed many Alder leaves on the ground. Click here for my blog post about finding and gathering alder cones.
After asking permission to gather, I collected quite a few to make a small dye bath.
I enjoy dyeing my own silk thread for embroidery projects and I never seem to have enough shades of green. Alder leaves can give a lovely green with a little help from something called a mordant. This is a substance, typically an inorganic oxide, that combines with a dye or stain and thereby fixes it in a material. In this case, an iron mordant is best.
There are many different kinds of mordants and many different ways to use them. One of the things I enjoy about plants dyes is the experimental quality of the whole process. Different seasons, regions, soils, water, soaking times, heat ranges, and fibers will give you different colors every time with the same plant material. Natural dyes are a vast world to explore, and each dyer will have different techniques that work for them. I’m going to talk about how I use iron dye baths, which suits my style of dyeing. But, I urge you to experiment and research on your own to find the way that works best for you. I highly recommend Jenny Dean’s Wild Color book for anyone interested in delving deeper. She gives very detailed instructions and measurements. I often consult her book for ideas, but I am the biggest ‘just eye ball it’ dyer in reality.
When beginning the dyeing process, I like to soak my plant material in a small pot. In this example, I’ll just be dyeing some silk embroidery thread and a little cotton swatch. My soaking time varies from a few hours to overnight depending on the plant material. For leaves, a few hours is plenty, since they’ll release their dye stuff readily, as opposed to bark or roots. (Their tough woody nature indicates they should be soaked overnight at least.)
Once sufficiently soaked turn the heat to low-medium and simmer them for an hour. After this, I let the mixture cool down to room temperature before straining out the leaves. I had this pot sit overnight to allow the dye more time to leach out of the leaves and into the bath.
Once the leaves are removed, the dye bath can be reheated to simmering and the fibers added. Simmer the dye bath on low for an hour and then let it cool to room temperature. I let this pot with the fibers sit overnight as well. I find that plant dyes become richer if allowed more time to adhere to the fibers, so I often let them sit 2-3 days in a dye bath before removing them to rinse.
Give this project the amount of time you feel is best. Thoroughly rinse out your fibers and wring them free of excess water when done. In this example, I got a nice golden brown from the alder leaves, but I wanted to shift this color to green. This is where the iron mordant comes into play.
Iron mordant is known for shifting colors to greens and greys and is best used on a fiber after it has been dyed with the plant material (although not always!). It is also one of the easiest mordants to make in my opinion. You simply take some old rusty nails or washers and add them to 2 parts water to 1 part vinegar within your desired size of vessel. Let it sit for 1-2 weeks and voila! Iron mordant! I keep my iron mordant for several months at a time until the water becomes too icky to use and then begin the process over again.
Now, with your still damp rinsed fibers, submerge them in your iron mordant. I always do this at room temperature. Check on the fibers every 10-15 minutes until you see the color emerging that you want. Then, remove the fibers from the mordant and wash them immediately with a gentle soap. Too much iron, or iron left on the fibers too long, will begin to break down the fibers and make them more brittle.
I used my very old iron mordant on these fibers and it’s begun to not give a uniform effect, which is what I wanted in this case since I like to have variegated green embroidery threads in my patterns. I would’ve created a whole new pot of iron mordant had I wanted a cleaner more uniform shift in the color.
You can see how varied the results can become when using natural dyes. This is part of the fun of finding your own dyeing style!
Let me know if you decide to try out iron mordant and what results you receive!