FEEDBACK FRIDAY: This Week in Natural Dye Questions

This week: Indigo dyeing without felting wool and what comes second and third in a 1-2-3 indigo vat?


When dipping wool breeds (cormo, finn) that have a tendency to felt, in an indigo vat multiple times for a dark color, do you have a technique or recommendations on how to avoid felting or shrinking of the delicate wool? Is my vat too warm? I usually try to keep it at 120 degrees. I find that oxidizing and cooling the yarn, then re-dipping in the warm vat causes the yarn to felt. 

Thanks for emailing. You might have a couple of variables that are causing felting. One is that the vat is a little warm if the fibers are then air oxidizing and cooling down. The other variable is that the vat is extremely alkaline and alkalinity, friction and temperature shock are really good for felting. I think you can lower the temperature of your vat so that it’s lukewarm. If you need to heat it in order to activate it, then let it stand so it cools before you start dipping.

I would also suggest that you water oxidize your yarn in a warm bath that is the same temperature as your vat. That accomplishes two things. One is that you aren’t pulling apart the dipped skein to open up the yarn and causing rubbing and friction, as the water will penetrate the entire skein and the oxygen in water will aid in oxidizing the yarn. The other is that you keep the yarn temperature as consistent as possible so that temperature changes aren’t shocking the yarn. What I’m describing is that you have a tub of warm water near your vat and when you remove the yarn from the vat, gently transfer it to the tub of warm water rather than hanging the skeins. Let them float and oxidize – you don’t really need to handle them much.

The other thing is if you create a strong vat, you might be able to get away with two dips to minimize handling and potential felting.

I hope this helps you solve this problem!

Related products:

Indigo extract

PH strips

I’ve enjoyed indigo powder as well as other natural dyeing materials from Botanical Colors. I also really appreciate you share the other people’s questions! What an amazing/helpful thing to do for the natural dyeing community!

I make my indigo vat with henna and calx to start with. (I’ve been experimenting with many other ingredients like fructose, fusuma wheat bran extract and so on. I got the 1-2-3 indigo vat recipe from you when I purchased indigo powder probably 2 years ago. In the instructions, you mix indigo with calx and then fructose (or henna).
I just noticed, in making the stock on the Indigo FAQ page on the website, after you hydrate indigo, you put fructose first and calx later. My understanding of indigo vat-making is after hydrating indigo, you need to make the alkali agent base first and then put the reducing agent later. Do you find the order of putting ingredients doesn’t matter once it is all mixed? In some books, it says just ” mix all together” in indigo vat making recipes. So probably it doesn’t matter, but I would love to know your opinion when you have a chance.

I usually mix the calcium hydroxide and indigo together first, but in observing other indigo dyers, have seen them create beautiful vats by mixing in the fructose first. I haven’t done any detailed experiments, but out of habit will mix indigo with “dissolved” calcium hydroxide and then add more water, and then the dissolved fructose.  The resulting vat is stirred very well for a period of time and then allowed to settle and reduce, so the interaction of the ingredients seems to work just fine regardless of the order of adding the ingredients.

Related stories:

How-to dye with indigo (the 1-2-3 vat)

Roundup: Indigo Dyeing Questions