More Madder on Cotton

If you read my post about the tannin-iron-madder experiment, you may have noticed that I divided the original dyebath in half. I didn’t explain why at the time. My rationale was this: I  worried that the iron would affect the subsequent colors I got from the exhausted dyebath.

For the rest of the experiment, I prepared small pieces of cotton cloth with three different treatments, which I’ll describe below.

You can read my original post here for a description of how I made the madder dyebath and prepared the fiber.

Usually when I’m extracting madder roots, I use calcium carbonate and soda ash to make the water mineral-rich and alkaline. The soda ash is inspired by a comment by Rita Buchanan in A Weaver’s Garden that “the pigment alizarin dissolves better in alkaline solutions.” In Jim Liles’  recipe for “Amish Madder Purple” he directs you to use calcium or chalk in the dyebath (though he specifies calcium acetate). He doesn’t mention pH, so for that sample I didn’t mess with the pH (which was 7).

However, in the other half of the madder bath, I added a half teaspoon of calcium carbonate *plus* a teaspoon of soda ash, which brought the pH up to 9. The bath got noticeably pinker.

Here’s the first sample from this dyebath. You can see that it has a bright pink quality. It’s cheery but also earthy, and I like it a lot:

When I’m working with madder, I try to keep the temperature below 160 degrees F. I have read some recipes that call for strategically manipulating the temperature higher than that, and even boiling for a limited period of time, but I haven’t tried them. So, in this case I kept the temperature below 160, maintained it for an hour, and let the fiber cool in the bath overnight.

Then I combined the two dyebaths and added the next sample. The sample below was tannin, alum acetate, and madder exhaust. I didn’t add any soda ash to bump up the pH, nor did I test it. To my eye, it’s more orange-brown than the first sample.

Lastly, I put in a piece of cloth that was not treated with tannin. This was a thick 100% cotton plain-weave piece. It was scoured, mordanted with alum acetate (along with the other aluminum acetate pieces I’ve described in this series of posts), and then dyed.

As I mentioned at the very beginning of this series of posts, I have often found tannin to be a frustrating factor in my dye process. For many years I have used aluminum acetate by itself without tannin when I’m dyeing cellulose fibers. This is the kind of clear, bright pink that I’m used to from a madder exhaust:

Here are the last three madder samples stacked up together:

Here is the full set of samples I made that week (December 18th-21st, 2017):

After all these experiments, I am:

  1. Excited about the possibilities of tannin to extend the range of colors I can get on cellulose fibers.
  2. Excited about trying alternate recipes for mordanting cellulose that I came across while researching these topics, including Maiwa’s process for a combined aluminum acetate-aluminum sulfate process as described here. Scroll down to the section titled “How to Mordant Cotton or other Cellulose Fibers”.
  3. Less inclined to think of cotton as my dyeing nemesis, with the caveat that…
  4. For cellulose fibers, I still love linen more!

Tannin and Black Walnut on Cotton

I have often joked that using black walnut hulls on white wool is perhaps not the best use of my time. Black walnut hulls make various lovely shades of brown, but there are plenty of brown sheep.

Dyeing cotton brown, on the other hand, makes sense. There are naturally brown cottons, but they are not commonplace. Sally Fox has spent many years breeding naturally colored cottons in a range of beautiful colors, which you can see for sale here. However, most of the cotton that’s available at the moment is white.

Using the same heavy cotton twill samples that I used for the tannin-iron-madder and tannin-copper-weld experiment, I ran some samples with black walnut hulls. I should note that black walnut itself is a source of tannin, so the tannin step at the beginning was probably redundant. However, for this series of experiments, I treated the whole piece of cloth with tannin originally before I cut it up for samples.

I usually use walnut hulls when they are fresh in the fall. But since it was winter, I used dried hulls. I made the dyebath with 1.5 oz. dried hulls, which I extracted three times over three days and then combined the dyebaths. I am a fan of really giving the plant material time to soak to get the most out of it. This is especially true when the material is dried and woody.

As you can probably read on the label, the sample above was made with the sequence tannin, copper, weld, black walnut. You can read all the steps in the tannin-copper-weld process in my last post. I cut that piece of cloth in half and then in half again for these walnut experiments. This one was dyed in the original full-strength walnut dyebath, along with the sample below. With all of these walnut samples, I brought the bath up to 180 degrees, kept it there for an hour, and cooled the fiber in the bath overnight.

Above you see tannin, iron, black walnut. It was dyed in the same full-strength bath as the sample above it. For the iron process, see my earlier post about “Amish Purple”. I really like this warm chocolate brown. I was expecting a darker gray-brown because of the tannin-iron combination, but I think that would require a more concentrated black walnut bath.

The sample above was tannin, copper, weld, black walnut exhaust. “Exhausting” means using the same dyebath again to get a lighter color. After I pulled the first two pieces out, I put in this sample and the one described below. The stray pink thread is from the madder exhaust (which I will write about later).

The sample above is tannin, alum acetate, black walnut exhaust. Alum acetate is the mordant that I usually use with cellulose fibers. Many dyers recommend it for cellulose, rather than aluminum sulfate (which is what I use on wool). After the tannin treatment, I mordanted some of the cloth with alum acetate at a rate of 5% of the weight of the fiber. Use caution with alum acetate, as the powder is very fine and light, and goes airborne easily!  Once it was dissolved in the dyepot, I added the fiber and maintained the temperature at 100 degrees. That’s basically the temperature that hot water comes out of my tap, so it doesn’t really need to be heated at all. Maintain that temperature for an hour, stirring regularly. As with other dyeing steps, I usually let things cool overnight.

Here they are all next to each other:

From left to right, they are: tannin-copper-weld-black walnut; tannin-copper-weld-black walnut exhaust; tannin-alum acetate-black walnut exhaust; and tannin-iron, black walnut. A nice range of browns!

Tannin, Copper, and Weld on Cotton

As I mentioned in my last post, tannin is an important component when dyeing cotton. The same week that I ran my tannin-iron-madder experiment, I also made this lovely color with a tannin-copper-weld sequence:


Here’s how I did it. For the scouring and tannin details, you can read my last post. For the copper mordant, I used the ratio of half an ounce of copper sulfate per pound of fiber. For the quantity of the cloth I was mordanting, that was about a tenth of an ounce of copper. I dissolved the copper crystals in a stainless steel pot, then I intended to follow Jim Liles’ instructions and heat the mordant bath to 150 degrees.

It got a bit too hot, up to 200 degrees, while I was busy with other dyepots, so I added some cold water and took the pot off the heat. Then I waited for it to get back down to 150 degrees before adding the wetted-out cloth. Once I added the cloth, I kept the temperature as close to 150 degrees as I could for an hour, then let the cloth sit and cool in the mordant bath overnight.

For the weld bath, I used a 1:1 ratio of plant material to fiber, and extracted the dried weld tops three times over two days. For the first extraction, I added water to the chopped up stalks, leaves, and flowers, brought the temperature up to about 150-160 degrees F, and maintained that temperature for an hour. Then I shut off the heat and let the plant material cool and steep overnight. The next day I strained off the dye liquid and repeated the process first thing in the morning, but I only let the plant material steep until the evening. I strained off the second bath, and extracted the plant materials a third time that night.

The next day I combined all three extractions, and added half a teaspoon of calcium carbonate to the dyebath. The pH was only between 7-8. When I first added the cloth, I was not very pleased with the color. It takes time for color to develop with natural dyes, but you can often get a sense of what might be happening with the first color “strike”, or how the fiber first takes in the color. I felt it was drab and uninspiring.

Here’s what it looked like at first:

Fortunately, I know that weld is pH sensitive, like many dye plants, so I pulled out the cloth and stirred in half a teaspoon of dissolved soda ash. This brought the pH up to 9. When I re-introduced the cloth, it was much brighter. Yay.

At this point I stopped writing down notes or taking photos. I was running several different dye experiments that week, in an overly-ambitious whirlwind of winter vacation before heading off to celebrate Christmas festivities with my family. Oh, and buying a car.

Typically I would heat a weld dyebath to not higher than 180 degrees, maintain that for an hour, then let the fiber cool in the dyebath overnight. Then I pull out the fiber to dry completely before washing and rinsing. Let’s assume that’s what I did!

Tannin, Iron and Madder on Cotton

Way back in December, around the time of the winter solstice, I ran some dyeing experiments with heavy cotton twill cloth. I have had some frustrations with cotton over the years, some of which I’ve documented here on this blog. On cotton yarns and cloth, I often get colors that are much lighter than I want, or a different shade than I was expecting.

Nevertheless, there are some colors and techniques that have always intrigued me. So in December I tried a recipe for “Amish Madder Purple” from Jim Liles’ book The Art and Craft of Natural Dyeing.

Cotton, like other plant-derived fibers, is primarily composed of cellulose. Cellulose is harder to dye with natural dyes than protein fibers. Protein fibers come from animals, for example: wool from sheep, mohair from Angora goats, alpaca from alpacas, llama from llamas, and angora from rabbits. Plant fibers can come from a wide range of sources, such as cotton, linen (from flax), hemp, and ramie (from a type of nettle).

Most plant-based dyes require a mordant, whether you’re dyeing plant fibers or animal fibers. A mordant is a metallic salt which bonds to the fiber and creates sites for the dye molecules to attach to. It’s like a bridge between the dye and the fiber. Protein fibers are able to bond with plant-based dyes much more easily than cellulose, due to their chemical composition.

When you are dyeing cellulose fibers, you need to add some extra steps to the process. One step that improves the depth and fastness of color on cotton is to use tannin in conjunction with your mordant.

The only downside of using tannin is that it can darken the color and make it more brown. There are lots of sources of tannin, some of which produce a light yellow or beige, others a pale pink, and still others dark yellows and browns. This page from Maiwa has some useful information about tannins. But I had found in the past that even with the lightest tannin I had tried (gallotannin from oak galls), I didn’t like the way colors shifted to a muddier tone.

However, for this recipe, the color was supposed to be dark and rich. So, tannin was my friend this time around.

Tannin combined with iron does something amazing! Check it out:

In the tub on the left are the samples of cloth that have been scoured in a liquid cationic scour from Earthues (via Nancy Zeller at Long Ridge Farm) along with soda ash. I used scour at a rate of 5.5% of the weight of the goods (the weight of the dry cloth), and soda ash at 2% of the weight of the goods. Following Earthues’ general directions, I dissolved both the scour and the soda ash in a pot of hot water, added the fiber, brought it up to 180 degrees F., then maintained it at that temperature for 30 minutes. I pulled out the cloth while it was still pretty hot and rinsed it well. I should say, too, that the cloth had already been washed in a washing machine with my usual laundry detergent. Well-scoured cotton is key.

Then the cloth was soaked in a tannin solution overnight (roughly 12 hours). For twelve ounces of fiber I used a little less than 4 oz. of gallotannin from Earthues. After that I let the cloth dry, then cut it into smaller pieces for my experiments. Each little sample was about 1.5 oz.

On the right hand side of the photo above, you can see the dramatic shift in color when the tannin-treated fiber was submerged in a solution of ferrous sulfate (iron) for 30 minutes. For the small samples I was doing, I used a quarter of a teaspoon of iron dissolved in a stainless steel pot with 2 gallons of hot water. Iron can make blotches, so I “worked” the fiber, meaning I picked it up and moved it around under the water. Wear gloves! This is an important safety rule when working with mordants. The color shifted noticeably after only ten minutes! I have to say, it was really exciting!

The last step in this “Amish Purple” recipe is the madder dyebath. A while ago I bought powdered madder root on sale from Dharma Trading. It is a little tricky to work with because it is very fine and hard to strain, but the price was right. I used about a 1:1 ratio of plant material to fiber, extracted the madder twice over two days, then combined the two dyebaths. I kept the temperature on the madder bath around 130 degrees F while it was heating.

Once the madder bath was strained, I divided the dyebath in half. In one half, I put one of the little samples into the dyebath overnight just to soak. In the morning I pulled it out, stirred in a quarter of a teaspoon of dissolved calcium carbonate, returned the cloth to the pot, and heated it. The pH was 7. While dyeing the cloth, I let the bath get up to 160 degrees and maintained that temperature for an hour.

Here are some photos of the madder bath on the stove:

On the far right above you can see the sample while it was still wet. Here’s what it looks like all washed and dried:

Here you can see the madder purple next to some pieces of tannin-iron cloth without any additional dye:

I really like the rich eggplant-purple in the madder sample. I expected the tannin-iron samples to be more of a charcoal gray, but they have a purplish tint as you can see here. Clearly, tannin on cotton is way more exciting than I previously gave it credit for!