Hot Stash Summer: Overdye with Indigo

Natural indigo has never been easier—give it a try!

Kate Larson Jun 21, 2024 - 5 min read

Hot Stash Summer: Overdye with Indigo Primary Image

Tan sock yarn after one dip in natural indigo. Photos by Kate Larson unless otherwise noted

We all have them—odd balls. Our deep stash might include extra skeins from sweater projects, a few balls of nice yarn in a color we no longer love, or a bag full of odds and ends from a colorwork project. When I started overdyeing my odd balls, I stopped feeling the burden of unloved stash. One dip in a blue bath, and these disparate colors are united, their now-subtle differences adding to the texture of whatever wonderfully scrappy project I choose.

Before and after one indigo dip: Handpainted skein of small-batch Bluefaced Leicester, green eco-wool, white cotton, and tan wool/nylon sock yarn. Depending on the color you start with, one dip might have dramatic results (white yarn) or very little change (green yarn). You can do more dips to create darker blues.

Natural Indigo: It’s never been easier

Makers in many parts of the globe have been extracting blue from plants for several thousand years. Both then and now, some artisans dedicate their life to the multi-step process, refining the art of indigo blue. From Peru to Morocco to Sweden to Japan, communities had their own approach to extracting indigo from specific plants and creating the dyepot conditions needed to produce blue cloth.

Juana Gutierrez grinding indigo dye at the Porfirio Gutierrez family workshop in Teotitlan del Valle, Oaxaca, Mexico. Photo by Themadatter, Wikimedia CC-SA-4.

This blue powder becomes a yellow-green indigo vat, sometimes the liquid is almost a clear yellow. After the yarn has been in the vat for a few minutes, yellow-green skeins emerge and turn blue in a matter of seconds as oxygen meets the dye molecules—it’s like magic. (See it yourself in the video clip below.) While the science of indigo is complex, many passionate natural dyers are creating indigo kits that make it easier than ever for everyone to give it a try.

A few weeks ago, I treated myself to an indigo kit I’d kept back for a special afternoon. I’ve worked with several types of indigo vats, and this was a natural indigo fructose vat. There were three ingredients: indigo powder, pickling lime, and fructose crystals. That’s it! During the summer, it is warm enough to keep my indigo vat in a plastic bucket outside and use it whenever I have the urge to create some blue.

Kate’s indigo vat.

Another amazing thing about indigo is that both protein (such as wool) and cellulose (such as cotton) fibers can be easily dyed. From scrap yarn to t-shirts, anything needing a refresh can take a dip. (While some synthetics don’t overdye with indigo, nylon can do well.) In my recent batch of indigo-dyed scrap yarns, I included a wool/nylon sock yarn. I have several balls of very nice solids languishing in my stash that are leftover from knitting argyle socks. One dip in my fresh indigo vat yielded a delicious variegated solid I can’t wait to knit. After doing this test skein, I’ll wind the remaining balls of yarn into skeins, loosely tie in three or four places, and go for a blue dip.

From tan to complex blues.

Learn more

One of the natural dyers I love learning from is Dagmar Klos. She filmed several videos, one on beginning natural dyeing and one on overdyeing. We are excited to share a clip of Dagmar dyeing with indigo here, and you can learn more about the other videos below. I hope you’ll give it a try this summer!

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Watch Dagmar’s whole course at


Kate Larson, editor of Spin Off, teaches handspinning around the country, has published knitting patterns in books and magazines, and spends as many hours as life allows in the barn with her beloved flock of Border Leicesters.

Dye master, fiber artist, author, technical editor, and teacher Dagmar Klos is the author of The Dyer’s Companion and numerous articles for Spin Off, Handwoven, and PieceWork. She served as coeditor and copublisher of Turkey Red Journal, a newsletter dedicated to natural dyes.