Indigo 101

Graham stirs the vat with his “witchy stick” –which is tinted many beautiful shades of blue.

One of the primary lessons of gleaned from my Shibori Challenge is that cotton is difficult to dye with natural dyes, whereas wool and silk take these colors beautifully. Know your materials!

Building on that, I’ve also figured out that the reason indigo dye is the favored dye for shibori techniques is because indigo gets along very well with cotton (and other plant fibers) and the dyeing characteristics of indigo are ideal for shibori. In fact, the idiosyncrasies of indigo probably led to the development of shibori, way back in the mists of time. So, if I want to make shibori patterned cotton cocktail napkins, as was my challenge to myself, I may as well fall in with thousands of years of tradition and dye with indigo.

Book reading and Internet surfing are all well and good for gathering knowledge, but to learn an unfamiliar process, nothing works better than to find someone who knows what they’re doing and go watch them. That way, you learn via a pleasant form of osmosis, rather than by frowning at at a glowing screen.

Our friend Graham Keegan dyes with indigo and sells his beautiful canvas and leather creations in his own Etsy shop. He kindly invited me to come to his studio and watch him dye some test swatches yesterday.

What follows are pictures and notes which I hope will help other indigo beginners sort things out.

Here’s a stack of stuff he’s working on :

And here’s some silk he dyed with bougainvillaea flowers. The two tone effect is just how it happened to dye. You rock, Graham!:

But back to the indigo.

Indigo seedlings on Graham’s front step. A hint from Graham: to ensure germination, scarify the seed with sand paper and soak overnight before planting.

• Indigo dye is plant-based, but rather than there being a single indigo plant, there are several varieties of plants which contain a substance called indican. Indican is water soluble and can be soaked out of crushed plant material to form the basis of indigo dye. If you’re shopping for indigo dye you’ll probably see either Indigofera tictorium, which is native to India, or Indigofera suffruticosa, which is native to Mexico and South America.

• You can grow your own indigo (any seeds you buy labeled as Indigo will probably be tictorium or suffructicosa). Indigofera is a pretty plant from the legume family. That family is valuable in the garden because it draws nitrogen into the soil. It would be nice to grow just as a conversation starter. I don’t know much about making the dye from scratch, but it is quite possible if you’re not afraid of fermentation and a little chemistry.

• Indigo is a fantastic dye. As I’ve said, it likes cotton. It doesn’t require mordants. It’s a strong dye which stands up well to sunlight and heavy washing. However, as with any dye, you do need to scour your fabric prior to dyeing.

• Indigo is well suited to shibori because it of one unique characteristic: the dye sort of sticks where it hits and stays there. It doesn’t work hard at seeping into folds and under strings. This is what allows for that particular, beautiful clarity of pattern.

• You can buy artificial indigo as well as natural indigo. The artificial is easier to work with, but gives you no bragging rights. The natural stuff is brewed up in vats–you will hear talk of “indigo vats”. There are many different ways to start an indigo vat. Some are based on fermentation and take a while to get started, others are built quickly on chemicals. The simplest is nothing more than urine and indigo powder.

For instructions on several different kind of vats see The Art and Craft of Natural Dyeing: Traditional Recipes for Modern Use by J.N. Liles. Other recipes can be found in the beautiful Shibori: The Inventive Art of Japanese Shaped Resist Dyeingby Yokisho Wada.  Definitely check this last book out of the library if you’re interested in shibori. It will blow you mind.

• When you go to buy indigo powder, keep in mind that you’ll probably use 1 oz. of powder in a smallish vat–say a 5 gallon pot which is not filled all the way up.

• If you’re going to dye with indigo (or really, any other dye) you’re going to need to invest in a big stainless steel dye pot. If you work with cold processes you can use plastic buckets. You’ll also need wooden and plastic tools.

• Graham invested in a fancy device that gives him both temperature and pH of the vat. It costs about $100 dollars but it’s worth it to him. Temperature can fluctuate quite a bit without harm, some people even dye cold, but pH is very important. Graham’s vat must be in the 10.5 to 11 range.

Why not use just cheap pH strips instead? Well, as Graham quickly learned, you can’t dip color strips into a dye vat!!! Yep. The results were always blue.

Temp and pH indicator

• It’s also important to use the best water you can. Graham has dyed with both LA tap water and water purchased from one of those free-standing water machines. He says he gets better saturation of color with the machine water.

• Also, you’ll need a line to hang the fabric on. It’s a very drippy process, so you either need to be outside or on a floor you don’t mind staining. Speaking of staining, don’t pin up your fabric with clothes pins. The wood can react with the wet dye. Either drape it over line or hang it by string. Basically don’t let anything touch the wet pieces except string.

• Indigo works via oxidation. As a result, everything is process oriented and nothing is What You See Is What You Get. The top of Graham’s indigo vat was deep purple. Beneath the purple sheen, the vat can range from deep blue to acid green depending on the state of the internal chemistry. Logic would tell you to dye when the vat was blue. No. You dye when the vat is green:

This isn’t ready to go yet. See how blue the dye is?
Graham was looking for this green. Though between my camera and your monitor I can’t promise what you see is the right green.

• When you pull fiber out of an indigo vat after its first dip, it will look nothing like the finished color. At first, it will look quite green, sort of turquoise, perhaps even yellow in spots. The cloth changes to a more even blue via oxidation right in front of your eyes after you hang it up.

The splotchy, greenish cast of this first dip is not a problem. It evolves in front of your eyes. And you’re going to dip more, anyway.
Here Graham is peeking in the folds to see if the oxidation is complete. Perhaps you can see the difference between this blue and the blue in the previous picture? It’s the same cloth, but its been hanging around for 15 minutes or so. The blue is much cooler than it was. He’s looking to see if any greenish/yellowish spots are hiding in the folds. Given time, they’ll oxidize too. You just have to be patient. If you dip again before oxidation is complete, you can end up with irregular color.

• Indigo dyeing is an additive process. The first dip yields a light blue. You may have to dip 10 times to get a deep blue-black, with rests in between.

• The color changes considerably on drying–it always turns lighter.

• I asked Graham if he’d had any indigo disasters (because we love disasters at Root Simple) and he said he hadn’t had any real big goof-ups, but that he’s sometimes disappointed because the final color isn’t exactly what he wanted. Sometimes the fabric just won’t get any darker, no matter what you do. And he doesn’t always know why that happens. He’s still learning, and natural dyeing by its nature is unpredictable.

• Finally, Graham showed me this book, Imprints On Cloth: 18 Years Of Field Research Among The Miao People Of Guizhou, China. It’s another book by Yoshiko Wada, who wrote the shibori book I mentioned above. It’s a picture book with some how-to’s, about this group of traditional peoples in China who are The Masters of Indigo. Their textile work is breathtaking, and its all done with ancient methods. For instance, some of their indigo fabric is a shiny metallic purple. Graham told me they get that color by dyeing with indigo and then by beating blood into the fabric. He added wryly that if he could find a blood supply, he might try it. I’ve got to get me this book.

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7 Comments

  1. Thanks for such good information. I’m not getting good seed germination this year so it could be I didn’t prepare my seed like Graham does. Scarification will be added to my process list for next year.

    Janet

  2. We have friends who run a textile business out of their home in the Miao area of northern Hunan Province, China. I have some of their shibori products, and they are beautiful!

  3. Funny how those tried and true methods so frequently work and the indigo is lovely. I’ve been giving some thought to which CA indigenous plants might be useful as dyes, not many are mentioned in “Tending The Wild”.

    Do you happen to have any Phacelia campanularia (desert bluebells)in your garden? They’re included in a number of Theodore Payne Foundation’s wildflower mixes so its possible you might have and I wonder if you could get a dark rust red dye from it. The entire plant, leaves and flowers are gorgeous but cause horrible dermatitis. I endured a week of agony after picking a massive bouquet once but the more interesting thing was that my hands and forearms were stained for a few days as well, and the stains were embarrassingly persistent. They gradually died out in my yard as the perennials filled in so I can’t experiment myself.

  4. Interesting post. When I did Kendo(Japanese fencing) the better uniforms and armor were indigo dyed. The indigo was supposed to have some anti-bacterial properties and help with odor control( mainly with the armor).
    Another thing of possible interest is dye made from fermented unripe wild persimmons. The dried dye looks like redish brown almost like dried blood. Apparently ninjas didn’t go around wearing black, but wore clothes using this dye to be able to blend in(instead of changing clothes like a superhero). It was also supposed to have antibacterial benefits also, good in case of wounds I guess. Growing up we had a persimmon tree and some times we would get a bunch of dropping unripe fruit and I wondered it I could use these(got to check the tree next visit now hmmm).

  5. “they get that color by dyeing with indigo and then by beating blood into the fabric.”

    Hemoglobin? It’s an oxygen binding molecule, so an experiment with some antioxidants on dyed fabric could be interesting. And it has iron.

  6. What is the name of that ph/temp indicator. I have been looking for one, but I’m not clear about which is a good one for dyeing. I read that the Hanna ones are good? And the whole calibration thing, sort of puts me off? Any suggestions?

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