Indigo Dyeing: Time and Patience

Learning about indigo continues….

I often receive questions about indigo dye that fades very quickly on a textile. When I ask the dyer how long the textile was immersed in the vat the response is usually “1 or 2 minutes”. That is not enough time! Each immersion in the vat needs to be long enough to permit the indigo to penetrate into the fiber: at least 10-15 minutes. Otherwise the dye simply sits on the surface of the textile, making it susceptible to fading and rubbing off.

Recently, I completed a series of tests in which I experimented with much longer immersions in the vat. Immersion times in the vat ranged from 20 minutes to 20 hours. A longer dip encouraged more dye to penetrate the fibers. The results are worth observing and discussing. All samples were neutralized in a vinegar/water solution and “boiled” to finish and remove excess dye.

indigo and time
Indigo on cotton, silk, and wool, each with a single dip in the vat

The most common method of achieving dark colors with indigo is multiple successive dips in the vat and there are definitely some advantages to building color in this way. Any unevenness of the dye will level out as the textile is immersed multiple times. This is  especially important  when dyeing large textiles in a small vat. (This is the reason why larger vats are better suited when dyeing large textiles; allowing the dye to reach more of the textile surface)  If the vat is large enough that the textile can be immersed and exposed evenly to the dye, longer immersion times may be a practical approach.

multiple dips
Indigo on cotton, silk, and wool with multiple (1-6) 15 minute dips
time exposure 2
Fabric woven of wool and cotton yarns. After a single 20-minute immersion, the cotton fiber is darker. After 2 hours, both fibers are close to the same color. After 18 hours, the wool has absorbed a great deal more indigo while the cotton has maxed out. Multiple dips in the vat are required to achieve very dark blues on cotton.

My usual approach to dyeing textiles is using woven shibori. The textile is gathered with the woven “stitching” threads, making a compact “package”, and exposing the outside pleats of the textile to the dye uniformly.

indigo, dobby weave
Cotton, woven shibori, multiple indigo dips

Lately I have been experimenting with itajimi shibori (folded and clamped resists), where many layers of cloth might be folded multiple times. When using mordant dyes or fiber reactive dyes, the dye usually penetrates through the layers. When dyeing with indigo (10-20 minute immersions), the dye fails to penetrate beyond the outside layer and into the cloth within the folds, despite multiple immersions. When the immersion time was increased to 24 hours the dye penetrated ALL the layers – like magic. More time in the vat allowed complete penetration of dye throughout the textile.

 

Lightfast tests were performed on all samples dyed with extended times in the vat by exposing 1/2 of the samples to four weeks in a window with direct sunlight.

 

Note: When dyeing protein fibers, care must be taken with the pH of the vat, as the fibers can be damaged by long exposure if the pH is too high. Ideal pH for protein is 9.5-10. 

 



GrowingColor

The North Carolina Arboretum is hosting the second Growing Color Symposium on March 8, 2018. Michel Garcia will be our keynote speaker. Join us if you can!

25 thoughts on “Indigo Dyeing: Time and Patience

  1. Catherine: Thank you for this post! What kind of vat did you make? Do you neutralize the cottons as well as the protein fibers with vinegar/water solution? And could you explain “boiling” particularly for wool. Thanks again.

    1. I neutralize all textiles, including cotton. When finishing cotton, I boil the textile vigorously for a few minutes. Wool and silk is heated to just below a simmer with a small amount of neutral detergent and kept at that temperature for a few minutes. It really does help to remove the unattached indigo on the surface.

      1. Thanks Catherine. I’ve been using hot tap water on my wools and now I know I can make it even hotter. It’s also nice to know that leaving shibori pieces in longer helps get the dye into all the unclamped areas. It makes sense when I think about it. I guess the areas that are done are just done and the longer soak allows the indigo to reach those other areas. There is so much to learn about this wonderful dye!

  2. Catharine, Which indigo vat did you use for the tests? The mysteries of indigo.. I wish I could join you in March.. I have another commitment then. Thanks for all you do with natural dyes… and your blog Judy

    On Mon, Jan 22, 2018 at 3:55 PM, Natural Dye: Experiments and Results wrote:

    > Catharine Ellis posted: “Learning about indigo continues…. I often > receive questions about indigo dye that fades very quickly on a textile. > When I ask the dyer how long the textile was immersed in the vat the > response is usually “1 or 2 minutes”. That is not enough time! Each ” >

  3. Thank you for sharing your experiments. I will definitely try soaking my next batch of silk scarves in the vat for 24 hrs.

    Jane Spencer

  4. Thank you for sharing your experiments. I will definitely try soaking my next batch of silk scarves in the vat for 24 hrs.

    Jane Spencer

  5. Hi Catherine, Great post. Thanks so much for sharing your journey with so many. It’s very much appreciated. love Allison

    Sent from my iPad

    >

  6. Thank you very much for this post. I learned a lot! If you have earlier post about Natural Dye I would love to get them!

    All the best from Ragnhild Rise

    Sendt fra E-post for Windows 10

    Fra: Natural Dye: Experiments and Results Sendt: mandag 22. januar 2018 kl. 22:55 Til: ragnhild.rise@sf-nett.no Emne: [New post] Indigo Dyeing: Time and Patience

    Catharine Ellis posted: “Learning about indigo continues…. I often receive questions about indigo dye that fades very quickly on a textile. When I ask the dyer how long the textile was immersed in the vat the response is usually “1 or 2 minutes”. That is not enough time! Each “

    1. I’m glad to hear this was informative. You can look back on all the previous posts – each relates to natural dye in some way and many of them address the use of indigo as I continue the learning process.

  7. Do you have a source for eucalyptus to dye with? I am looking for red ironbark eucalyptus leaves that I can purchase.

    Jane Spencer

    1. Sorry, Jane, I don’t. The only eucalyptus I use is from a plant or two that I grow in the garden each year in North Carolina. Most eucalyptus comes from Australia. Susan Fell McLean collects and sells some but I don’t know if she ships abroad http://www.gondwanatextiles.com/ . There are some varieties that grow in California but I don’t know much about them.

  8. Hi Catharine, I found this article so interesting. The long dip with the itajime is stunning!

    I’m curious what your method for boiling to finish the cloth after dyeing is these days. Are you still boiling with bran and soap? And for how long? I’m working on a big new commission tapestry with lots of indigo so it has to be as good as I can get it.

    Many thanks, Sara

    Sent from my iPhone

    >

    1. Hi Sara, I typically boil with just a bit of neutral detergent. The boiling assures that any unattached dye is removed and Joy indicates that it actually helps the indigo move deeper into the fiber.

  9. I was actually dyeing an itajime piece when your post arrived to me. So I left it soak all night in the vat, and yes, I confirm that it makes a big difference. the dyes reaches all layers of the fabric. Thank you for sharing

  10. Hi Catharine
    Thank you so much for all the helpful replies to the comments…they are so useful. Sorry if this is a really basic question but when you make a small vat in a glass jar did you leave it with the lid secured on…just want to check incase it would make the glass crack if I do this.
    Also any tips on where to purchase Henna?
    Thanks so much

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