How to Dye Natural Fabric with Natural Indigo Powder
By Natasha Hoover
The Indigo Plant
Indigo - Natural Dye for Natural Fibers
Indigo is natural dye used since ancient times to produce beautiful blues that range from sky blue to deep, almost black blue. Frequently, people are nervous about dyeing with indigo. It is a tricky dye to work with, mostly because it is not water soluble and will not bind to fabric unless the dye vat is deprived of oxygen. Over the course of several years, I have followed various indigo dye recipes available online with little success. It could be my fault, not the recipe's, but the end result is the same. Finally, after year's of effort, I have discovered a recipe for indigo dyeing that actually works. The following recipe was adapted from by J.N. Liles. It has worked for me every time I have tried it, and it will work for you, too, as long as you follow the steps carefully. The Art and Craft of Natural Dyeing
Materials Needed to Dye with Indigo
First, you need to assemble your materials. Unless you live somewhere near a store that carries natural dyeing items, you will probably have to order several of these items online. I am sure there are many stores that carry natural dyes, but the only one I have personally visited is Earth Guild in Asheville, NC. Growing up, my mom and I used to make special pilgrimage-esque trips to Earth Guild.
How to Choose Natural Indigo
The type of dried indigo you purchase can have an impact on your dye vat, and the color of the items dyed. I prefer to use natural indigo that has already been powdered. The powdered form is easier to work with, but natural indigo also comes in lumps and cakes. If you purchase non-ground indigo, you will need to grind it. I highly recommend natural indigo over artificial indigo because it produces better colors. Historically, when artificial indigo became available in the nineteenth century, customers sought out goods dyed with natural indigo because it was considered superior. Natural indigo really is better - it can create a deeper blue, and, since it is not water soluble, you can wash natural indigo over and over without any color loss.
Great places to get indigo supplies
Needed Equipment for Indigo Dyeing
You will also need a jar or water bottle with a tight lid, a 2 gallon bucket with a tight lid, a pair of latex (or similar material) gloves, lye, thiourea dioxide (also known as color remover) and potassium hydroxide. Lye can be easy to find at a home improvement store being marketed as drain cleaner. For the thiourea dioxide and indigo, check online with Dharma Trading Company or Aurora Silk. Both sites supply natural indigo dyeing products.
How to Prepare Indigo Stock
Next, prepare your "stock." Mostly fill your jar or bottle with hot water. I just use water from the hot tap of the sink. Then, add 1 1/2 teaspoons of lye and 2 or more teaspoons of indigo powder. If you want your textiles to be sky blue, go with 2. If you want them to be a dark, midnight blue, use up to 5 teaspoons. I usually use 2 or 3. Then, screw the lid on tightly and shake for 2 minutes. Next, add 2 teaspoons of thiourea dioxide, recap and shake for an additional minute.
How to tell if Indigo Stock is Correct
I know if is difficult to tell in the photo because I used a green water bottle, but the stock should not be completely blue. It should have a bubbly, coppery blue/green/purple appearance. If it looks funky, you're on the right track! Make sure the lid is on well to prevent extra unnecessary exposure to air and simply let the stock sit for at least 15 minutes. I usually let it rest for 30-40 minutes.
How to Prepare Indigo Vat
After your stock is ready, you can prepare the vat. I just put my 2 gallon bucket in the sink and fill it up with hot water. Then, you add 1/8 teaspoon of lye and stir until dissolved. I like using a big metal spoon, but you can use plastic, too. Do not use a wooden spoon to stir the indigo because the wood will actually absorb the dye. Next, add 1/2 teaspoon of potassium hydroxide and 1 teaspoon of thiourea dioxide. Stir again.
The next part is a little difficult. You definitely want to wear your gloves. I only have the wrist-length gloves, but a pair of elbow-length gloves would be better. You must add the stock to the vat while introducing as little air as possible. I usually submerge the bottle, at least partially, and then remove the cap. Because indigo will only dye a material when it is deprived of oxygen, allowing excess exposure to air can ruin your vat. The vat will probably have a top foamy layer that turns blue. This is okay. However, the bulk of the liquid should be a deep green and the vat should have a coppery sheen. If your vat is blue, you can try to salvage it by mixing in more thiourea dioxide, but you may simply want to start over.
After closing up your vat, let it rest for at least 15 minutes. Then, you are ready to dye.
Dye Natural Fiber Fabrics with Indigo
You will achieve the best results when you only dye natural materials because the indigo does not bind well to synthetics. It basically doesn't bind at all. Wool, cotton, linen and silk are all fairly easy to dye with indigo. No mordant (a presoak solution that improves color retention with some natural dyes) is required when you dye with indigo. However, you should make sure to wash your fabric or other items before dyeing to remove any chemical finish that may have been applied in the manufacturing process. You should also soak whatever you want to dye in warm water for several minutes before dyeing. This encourages an even application of color. Make sure to wring the item out lightly before dunking it in the dye vat.
Unlike most natural dyes, the length of time the items spends in the vat does not dictate the richness of the color. An item should only be submerged for a few minutes at a time. If you want a deeper or darker color, simply re-submerge it after it has dried. I usually hold the cloth in the vat to make sure it remains submerged. When you are ready to remove the item from the vat, try to wring it out a little while it is still submerged. When you remove it from the vat, attempt to avoid letting the runoff dye flow back into the vat. This dye is useless for re-dyeing after it has been exposed to air, so letting it run back into the vat is detrimental.
How to Make Sure Indigo Does not Bleed or Fade
You can either wave the cloth around in the air by hand until it dries, or, more practically, drape it over a line, shower curtain rod, etc. If you use a line, make sure it is a non-natural material. As long as the dye is wet, a natural material can and will leach dye from your textile. This includes wood clothes pins, so be careful! Because the wet dye will run, you may want to reposition the fabric every few minutes to make sure the dye application remains even.
Last, you need to make sure your newly-dyed textile won't turn you into a Smurf. Excess dye will remain in and on the textile, unbound and ready to rub off on you and your belongings. If you have ever dyed your hair, you know the drill - wash until the water runs clear. You can do this yourself, or you can just throw items in the washing machine on a quick cycle without any detergent.
After this, your natural indigo item will not loose any color in the wash, unless you do your laundry with lots of lye soap. However, indigo is only mostly light fast, so prolonged, direct sun exposure will eventually fade the dye.
If you cannot get the indigo vat to work correctly for you, you are not alone. I struggled with indigo for years and tried every recipe I could find, including ones that call for all manner of strange things (like wheat bran and corn syrup). This recipe is the best, most consistently successful one I've ever come across. I hope it helps someone achieve indigo dyeing success.
Watch the magic of indigo
The instructor in the video is a lady named Eve who conducted a workshop on indigo at an ALHFAM regional conference at Historic Brattonsville in late February, 2012 and I have posted this video with her permission.