A film series and discussion forum dedicated to the science and practice of natural dyes and pigments using sustainable methods.
Recently, one of our readers wrote to us with questions relating to her indigo vat. Here’s her message verbatim –
“Before I bought the video, I tried mixing the indigo vat using Michel’s instructions for natural indigo vat found on the internet. I didn’t have a thermometer to measure the temperature and I think I had it too hot as the indigo stock didn’t change colour after adding the fructose and lime. Can this stock be revived or used? I tried to revive it by heating it as instructed but nothing happened. Does anyone have any suggestions?” – GL
Since we receive a lot of queries regarding the making and maintenance of an natural indigo vat, we asked two experts who have worked extensively with Michel Garcia to respond..
In this post i.e Part 1, we share what WSN President Yoshiko Wada had to say –
It would be good to have the following to have a successful indigo vat going – thermometer, pH paper, measuring cup (in liters).
1- 100gm > Indigo. Did you use natural indigo powder ? We sell some at our shop.
2- 200gm> Calcium. Did you use calcium hydroxide/ pickling lime?
3- 300gm> Fructose. I suggest you use liquid from cooking vegetable scraps and fruit peels (no citrus). Michel calls this “syrup”. This syrup can be used in lieu of / along with water that you want to make the vat with. To make the syrup, cook the peels/scraps for 45 minutes to 1 hour, strain and use the liquid when cooled a little.
4- Temperature around 60C is good but it can bear up to 80C. So, I don’t think that temperature caused the problem. I say the temperature is right ” if you put your finger in it and it’s hot enough that you don’t want to stay there.”
5- Massage or shake the indigo powder with a small amount of water to hydrate the powder into a soft paste.
6- Add enough water to lime slowly, to make soft paste.
7- When all 3 ingredients are mixed in the “syrup water” (antioxidant), you need to stir it thoroughly for 5 to 10 minutes. Ensure you scrape the bottom, as sediments settle in the bottom of the pot.
You begin seeing blue, reddish bubbles and oily slick surface film that is metallic looking and a bit coppery. This is the sign of reduction taking place.
8- Let the vat rest for a few hours and check and see if below the surface in the liquid, you see brownish transparent liquid. Then the reduction is complete. You can wait for a couple of hours before dipping yarns and fabric to capitalize maximum amount of reduced indigo liquid for dyeing. You probably get pH11 which is alkaline. it is fine with plant fiber materials, but not for wool. You may wait until the vat gets used and pH lowers to pH10 or pH9 if you want to use wool.
9- Be sure not to introduce oxygen to the vat while dyeing. Remember, making an indigo vat is one thing…dyeing with it, a completely different one. And finally, to maintain the vat requires attention and care.
Where do you live? Catharine Ellis is teaching a class this summer with Joy Boutrup from Denmark at Penland School. I suggest you take a class from her, Elin Noble, Sara Goodman, Ana Lisa Hedstrom , Barbara Shapiro or me who have studied with Michel Garcia and continue to practice it with depth of knowledge required for natural dyeing.
Watch out for our next post which will feature the response from renowned woven shibori artist and natural dyer Catherine Ellis.
I was asked why a henna indigo vat stripped the color from a previously fiber reactive dyed cotton cloth. This color stripping does not occurred with the iron vat I usually use. Could the anti oxidant properties in a strong henna vat have that effect?