Indigo workshop

It was a pleasure to return in June to the Bedfordshire Guild of Weavers, Spinners and Dyers, of which I was a member for over thirty years before we moved to West Sussex. The occasion was an indigo workshop I was leading and I was delighted to see old friends and to meet some new members.

To demonstrate the various sources of indigo dye, I made several vats using natural indigo, synthetic indigo, woad leaves, woad balls and stored woad solution.

I used the Colour Run Remover recipe given in my books with the synthetic indigo. However, as Colour Run Remover is not always easy to find in powder form (the liquid form isn’t suitable for indigo vats), I decided to try a different method with natural indigo. I was looking for a simple method and, after some experimentation, it seemed that using equal quantities of indigo powder, washing soda and sodium hydrosulphite (hydros) would work well. An added advantage is that using equal amounts of each ingredient makes this a very simple recipe. As indigo reduces better in a more concentrated solution, I decided to make a stock solution on the day before the workshop. To do this, I mixed 4 teaspoons of natural indigo powder with very hot water to make a paste. Then I dissolved 4 teaspoons of washing soda in very hot water in a strong glass jar, added the indigo paste and stirred well. I added more hot water until the glass jar was just over three-quarters full then, after checking that the temperature was not above 50C, I carefully stirred in 4 teaspoons of hydros and put the lid on the jar. I then placed the jar in a saucepan of very hot water and put this on a hotplate overnight. In the morning I checked the pH and added more washing soda to bring it to pH9. The solution looked a murky greenish yellow at this stage. When I arrived at the workshop, I filled a stainless steel bucket with very hot water (but no hotter than 50C) and added 2 teaspoons of washing soda and two teaspoons of hydros. I then gently added the contents of the glass jar. The vat was allowed to stand for about 20 minutes until the liquid below the surface was a clear greeny/yellow. (If this seems to be taking too long, add some more hydros.) This vat is very simple to make and worked well. However, I intend to experiment further to see if I can improve on this method.

Both of the indigo vats produced dark blues immediately and those students who wanted paler blues had to wait until some of the blue had been used before dyeing their samples. I also suggested that the wool samples should be dyed first, while the vats were hot, and that the cotton and silk samples should be dyed later, when the vats had cooled down. This is because wool takes up the indigo dye better in a hot solution, while cotton and linen prefer cooler solutions.

With the woad balls I used the recipe given in the revised edition of  “Wild Colour” and also in an earlier post on this blog. Unfortunately, the woad balls only produced a pale blue and not enough for all the workshop participants to dye their samples. I think the balls probably needed to steep for a longer period than we had available. We also had limited success with the fresh woad leaves, which gave very little colour. However, I suppose this was to be expected, as June is really too early to harvest the first year leaves, which hadn’t had enough time to develop their colouring potential. The woad solution, which gave deep to mid blues, was from 2008 and worked very well, so this proves (if proof is necessary) that correctly-prepared woad solution can be stored successfully for several years. The recipes I used for these two woad vats were those in my books.

The photos below show some of the materials dyed by students at the workshop.



8 Responses to “Indigo workshop”

  1. Maggie Stearn says:

    Now I'm even more sorry to have missed this workshop!

  2. arlee says:

    Alas, no one ever comes to Calgary to do these things…………if i win the lottery, you'll see me everywhere!
    Shall have to make note of that indigo recipe too 🙂

    • says:

      I hope you’ll find the simple indigo recipe useful. Once the initial solution has been made using equal amounts of each ingredient, adjustments can be made according to whether the pH is too low (add some more washing soda) or the vat is taking too long to change to greeny-yellow (add more hydros)

  3. Louisa says:

    We can't get sodium hydrosulphite here in Canada and instead substitute thiourea dioxide which is used at about half the amount. Kind of spoils the symmetry of your recipe, Jenny! However it's good to know that my woad solution which is from Oct 2010 isn't desperate to be used right away. There's more woad in the garden now but we haven't had enough warm sunshine yet. And I'm growing Japanese indigo for the first time this summer and excited to see how that goes.
    Hey, Arlee, if you're ever in Vancouver let me know and we can get together for an impromptu Blue Session!

    • says:

      Sorry I failed to consider users of thiourea dioxide when I devised my new indigo recipe! I’m not sure what to suggest but, if you already have an indigo recipe that works well for you, I would suggest you stick with that! Your woad solution should keep for several years if you want it to but make sure you incorporate all the sludge from the bottom of the liquid, as that’s often where the best indigo is lurking.

  4. neki rivera says:

    dying to try this recipe to see if i have some indigo success after all my failures. thank you!

  5. Alisay de Falaise says:

    I want to know if you already have matched the 10 colors of the Bayeaux Embrodery with the Color Specifier Pantone…. and the «natural» wool is not included in the 10 color.
    There are their specification :
    a red-rose or orange with rubia tinctorum
    a red brown violet with the same
    mustard yellow with the reseda luteola
    a beige with the same
    a black blue with indigotine
    a dark blue with the same
    a medium blue with the same
    a dark green with indigotine and reseda luteola
    medium green with indigotine
    a pale green with the same
    Your help will be greatly appreciated!

    • says:

      I have certainly achieved the colours you mention & from the sources indicated. The recipes for most of them can be found in my books.