For the last couple of months, I’ve been dyeing hundreds of handkerchiefs using natural dyes as I work on a project for a show in the spring. So far I have successfully worked with madder, weld, cochineal, pomegranate, myrobalan, cutch, various parts of the oak tree, walnut, and indigo.
I waited to work with indigo till I had some experience under my belt. It’s a trickier dye to work with than others because it’s insoluble in water and has to be reduced to a water-soluble form. To make an indigo vat, you have to follow steps to create the chemical reactions needed for the indigo to convert to a dye rather than a pigment.
To make the indigo vat, you have to create an alkaline environment in the vat (adding lye or soda ash to the water for example), remove the oxygen (adding thiourea dioxide in my case), add the indigo “starter” you made earlier, check the pH, adjust the pH to the correct one for the fiber you’re dyeing, then you can start. You then adjust the vat as needed each work session, adding the necessary ingredients for each chemical change to occur.
Other colors are much easier to work with and just involve steeping dyestuff for hours or days.
What’s been so exciting about working with indigo the last 2 weeks is that I’ve added a whole side of the color spectrum to my handkerchief palette. I’ve been able to overdye reds and yellows to make a range of turquoise, greens, violets, and lavenders. If you look at the images below, you’ll notice that some of the handkerchiefs are much darker than others. This involves dipping the hankies multiple times in the indigo, anywhere from 5 seconds to 5 minutes at a time. And the magic of indigo is that when you take fabric out of the vat, it comes out yellow or green and only turns blue in contact with air. It oxidizes over the course of the next 30 minutes to reach its peak blueness. You can then dip it in the vat again to make it darker and bluer.
