Discharging of Indigo Dye

It is my belief that learning about natural dye takes a whole community of people who are willing to experiment, observe, and share. The sharing has been the most rewarding part of my own journey in natural dyeing. I have met many dyers, both in person and virtually, who are willing to be part of that communal knowledge base.

While my co-author,  Joy Boutrup, and I were preparing and writing The Art and Science of Natural Dyes, we experimented with potassium permanganate, a strong oxidizing agent that can be used to discharge indigo. It provides a unique approach to removing indigo dye. When combined with resist, such as “itajimi” clamps, wonderful resist patterning will result.  Changing the chemical treatment will result in a “permanganate brown” color. When the textile is pre-treated with a tannin, it is possible to achieve even darker brown colors juxtaposed with the indigo. All of these recipes/processes are included in the book. 

But direct application or printing with the potassium permanganate proved problematic. Any gum used to thicken the mixture rendered it chemically useless for discharge. In the book, we included a resist paste made with soy flour and lime (calcium hydroxide) in order to achieve some controlled resist printing effects. I had learned to make this paste while in China and found that the paste could be used as a resist for the potassium permanganate solution.  Unfortunately, the soy/lime paste, although effective, is harsh and very difficult to remove from the textile. 

After The Art and Science of Natural Dye was published, we received an email from Zoë Sheehan Saldana, an artist who has been using potassium permanganate. She experienced the same challenges when printing – but she solved the problem by thickening the potassium permanganate with a fine clay. The clay is inert and does not interfere with the chemical oxidation of the indigo.  Either bentonite or kaolin are suitable clays. These are the same types of fine clay that are used with the indigo resist paste. The printed application of the paste in her bandanas results in an even discharge and the printed patterns become pure white.

Use enough clay to achieve a suitable thickness for painting or printing with a screen. Varying the amount clay, as well as the application method, will result in hard lines or soft edges. When painted on, rather than printed, an uneven layer of the paste and the discharge can result.

Mix the paste in small batches, making only the amount that you think you will need.  The paste is most effective when used fresh, but if kept tightly covered it can last for a couple days.

Indigo discharge, using a painted application, by Amanda Thatch. taking advantage of the uneven thickness of paste that results from the brushed on application.

During this week of the United States holiday of Thanksgiving, I am grateful for the community of dyers and experimenters out there, who are willing to share and make our knowledge base stronger. Thank you. Happy Holidays!

11 thoughts on “Discharging of Indigo Dye

  1. Thank you !
    So grateful for our connection.
    I’ve been very interested in this process….are there better sources for P.P. ?
    Happy Day of Thanks to you !

    1. I have been able to purchase potassium permanganate at my “big box” home improvement store – in the “water filtration” section. as it is as part of a water treatment for metals in household water.

  2. Thank you Catharine! We are thankful for you too. I have been using bentonite clay as a clay paste resist before dying and now I am anxious to try it for discharge on indigo. Happy Thanksgiving

  3. You are so amazing. 




    Debra FrasierAuthor and Illustratorwww.debrafrasier.com


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  4. And we are thankful for your good work and sharing it so willingly. Your inspiration keeps us excited and the pot going! Nancy ________________________________

  5. Thank you Catharine for this enlightening article. Be well and Best Wishes in the New Year. Gale, from Canada 🇨🇦

    Sent from my iPad


  6. Thank you for sharing this information, Catharine, and thanks to Ms. Saldana for her generosity too. I have gone over the recipes in your book and tried to determine a good recipe for Potassium permanganate and clay paste in order to achieve a discharge on indigo dyed linen to a bright white (like Ms. Saldana achieved) but alas, I don’t have the experience. Can you offer more advice?

    1. You would use recipe #36 from the book, making only the amount you would need of the potassium permanganate solution for direct application. Thicken to the desired. consistency with the clay. Apply the thickened solution to the indigo dyed textile and allow it to sit for a little while, until it looks a “brownish” – about 20-30 minutes. Then immerse the textile in the citric acid solution, as the recipe specifies. Hope that helps. Don’t be afraid to experiment!

      1. Thank you Catharine, for spelling this out. I appreciate your quick response and I look forward to experimenting as soon as possible!

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