Natural Dye Workshop with Michel Garcia and Sustainable Dye Practice
A film series and discussion forum dedicated to the science and practice of natural dyes and pigments using sustainable methods.
Indigo Vat Question
On the DVD, Michel uses vinegar for the mordants, I am working on a commercial scale, is there a substitute?
Yes, of course, it is much easier to use the sodium acetate from Maiwa. Then, the proportion of alum doesn’t change in the formula, but the sodium carbonate and the vingar are replaced by socium acetate. e.g.: for 1 litre of water, dissolve 50g of alum + 50g of sodium acetate- this mordant is very concentrated and used for printing. For immersion dye, it can be diluted with water.
I have followed the 1-2-3 Indigo recipe with fructose, it would be helpful to have some info on what to do when it doesn’t work….mine isn’t working and I am wasting too much indigo trying.
The best solution is to add more sugar and wait for about one day: the the sugar is converted in lactic acid: the pH is decreased while the reduction is very strong
-Michel
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Natural Dye Workshop with Michel Garcia and Sustainable Dye Practice 
Dominique Cardon’s book mentions using clear gelatin to protect wool. Does anyone have experience with that?
I don’t have experience with gelatin but some books or dyers recommend hide glue be added to protect delicate fibers- fine wool, kid mohair and even silk. I would think hide glue and gelatin are pretty similar products. I think the hide glue lightly coats the fiber. Of course somehow the dye penetrates without destroying the fibers.
Thanks for your reply. I have read that as well, but was wondering if anyone had tried the gelatin (easy to obtain) in a controlled test situation resulting in wool that is not so badly damaged by the alkali state of the indigo.
Earthues and their dealers sell hide glue in bulk. It’s probably cheaper than gelatin long term but for a quick fix I’ld try the gelatin.
I’ve another question to Michel about the 1-2-3 vat. I always learned to keep my vat on temperature, 50° for wool and below 50° for cellulose. The DVD is not telling us about the temp. only to use hot water for the start. During a day or a few days the vat will be cold. Isn’t temperature not important then ????
I have made a fructose indigo vat and wonder if fructose from corn is anti oxidant as regular fruit based fructose. Reason is I can only find crystals (fructose) from corn and my vat has a super high ph and I have added 25 g of indigo but hardly get color. I dont want to add too much sugar. Am I on the right track?
Dear Rio Wrenn,
Thanks for your inquiry! We have responded to you below, since thedomesticbarbarian asked a similar question.
I dont see the response.
Dear RioWrenn,
Apologies. We’re not sure why it wasn’t posted. Here’s our response:
To answer both thedomesticbarbarian and rio wrenn,
Indigo can be kept going as long as the ph is somewhere between 9-11. You can reinvigorate it by stirring it the day before you want to use it. Check the ph, if it is less than 10, you may sprinkle some Calcium Hydroxide i.e. hydrated lime to restore the ph. You also need to heat up the vat. The best way to do this is with creating a hot fructose solution. You can create this by collecting the peels of mangoes, pears, apple and peaches and boiling them in 1/2 of a gallon of water for 45 minutes, until the solution is cloudy. Slowly add small amounts of this hot liquid into your indigo vat while stirring. The question for you: What is the amount of liquid in your indigo vat vs. the amount of indigo powder, what is the ph and what is the temperature? The ratio between all of these 4 factors are key to maintaining a successful vat. The more fabric you dye, the more of the indigo pigment is depleted in the vat. Therefore, you need to constantly restore your vat with a strong stock solution, i.e. small quantities of liquid to indigo powder to create a strong indigo solution to add to your main vat.
When you are dyeing, take care not to airate the solution, by introducing bubbles and water (which contain oxygen) into the indigo vat. This oxygen depletes the vat quickly and will not give you dark blue.
If you need further directions, you can check out Yoshiko Wada’s book: Shibori, page 280-283. In the text, ignore the use of the reducing agent as zinc powder. You can replace the zinc with fructose, henna, iron sulfate, or the fruit scrap solution.
Let us know if you have further questions!
I made a 1-2-3 vat with fructose as the reducing agent. The vat appears to reduce: I get the coppery sheen, the pH is about 11, and the liquid is the color of dijon mustard. But I’m not seeing much of an indigo flower, just a very few bubbles. Is this ok?
Can granulated sugar be used? I have no dying experience and I was given a small amount of natural indigo and calcium hydroxide which I don’t want to waste. The 1-2-3 method seemed the most fail-proof option, but the health food stores nearby don’t sell fructose crystals.
Dear Novice, In Michel Garcia’s DVD 2, he explains how to make fructose from common kitchen scraps such as carrots, beets and other ripe fruit peels (* no citrus) The method is simple – cook the peels for one hour and strain the liquid. This liquid can be used in lieu of fructose while preparing the vat. Detailed instructions are available with the purchase of the DVD!