Color mixing

It has been a while since I have posted here, but I assure you that I am staying busy, still learning, and have been developing some new projects and ways of working.

Last year, Schiffer Publishing Co. approached Joy and me about making the the recipes that are included in The Art and Science of Natural Dyes more accessible to the user. A we thought about how to accomplish this, I was reminded that in my household kitchen, I use the same recipes over and over again and used a recipe box and cards regularly. Maybe this would be a good idea for the dye kitchen as well.

This invitation to increase the usefulness of the recipes seemed like a perfect opportunity to share the dye color work that I had been developing for many months in the studio and has finally resulted in The Studio Formulas Set for The Art and Science of Natural Dyes: 84 Cards with Recipes and Color Swatches. It is scheduled to be released by the end of June.

In 2020 I posted about Dominique Cardon’s newly published Workbook, Antoine Janot’s Colours. This little book has been a great inspiration to me. It was surprising and enlightening to find that Janot’s full palette of 55 colors was made with only 4 dyes: indigo, madder, cochineal, and weld. That bit of information has mostly changed the way I am now thinking about dyeing and color.

When I first began using natural dyes I thought it was important to have/use/stock every dyestuff and dye extract that I could get my hands on; I didn’t want to miss any opportunity! The large number of dyes on the shelf always led to confusion when I got ready to dye. At some point, I finally did lightfast tests on all the dyes on my shelf , making fastness to light a criteria for selection. Ultimately, I ended up with a much smaller number of dyes I was willing to use. Those are the dyes that we include in The Art and Science of Natural Dyes.

The documentation in Janot’s workbook helped me to take color and color mixing to the next step, which was truly learning to master my dye colors.

The first thing that I felt I needed to do was learn to control the various shades of indigo. Janot used 8 different shades of blue, each with its own name. I had to learn how to consistently achieve different shades with my fermentation indigo vats. My goal was 6 different values. Dyeing consistent blues is like capturing a moment in time, as the vats change over their life span. My first fermentation vat was over 2 years old before it finally gave me the pale blue that I needed for some of the color mixes.

The 8 shades of indigo blue used by Janot

The 6 values of indigo blue chosen for use on the cards and subsequent color mixing

So, I began dyeing a series of predictable, repeatable color using indigo and a handful of other dyes using various depths of shade.

Various shades of yellow from weld

Various shades of indigo + a strong weld result in one set of green colors

The same shades of indigo with a weak yellow results in a different set of greens.

My lab notebooks are fabulous repositories of all of my testing (I am now on volume #10) but they are not always the most convenient place to go for a quick color reference. So, I began putting my color mixes and repeatable dye colors on cards – the kind that you can file in a box for easy reference. And then I began USING that reference. It was at my fingertips and ready to look at whenever needed

I realized that this was also a perfect opportunity to combine the recipes from The Art and Science of Natural Dyes with a set of color mix cards, that will give the dyer some basic color mixing information.

The dyes included in the color mix box are: indigo, cochineal madder, weld (and a little bit of the tannin dyes: pomegranate rind and cutch )

I have used my “box of colors” in teaching over the last months. It is rewarding to see students refer to the cards, make their own color choices, and their ability to achieve very similar results.

Teaching at Sanborn Mills Farm using my own set of color cards.

To follow soon: ideas of how to best use your own set of “Box of Cards” in your own studio dye practice.

I recently took on a small weaving commission that required the use of black wool yarn. For a brief moment I contemplated purchasing the wool in the required color and then decided that I could dye it. I was surprised at how easy it was to achieve a rich, deep black color on the wool using only indigo and madder.

Commissioned weaving using wool yarns dye with indigo blue, madder red, black from indigo and madder

It inspired me to continue my current series of color studies, woven in cotton and linen, with an in-depth exploration of black dyes.

Initially, I wanted to achieve all the black hues without the use of an iron mordant. My years of mixing hues with primary colors gave me the confidence to believe that I could mix a good black for cellulose using 3 primary colors: blue, red, and yellow. The key was going to be finding the correct proportions.

The first step was to build up a deep layer of indigo blue (usually 8-10 dips in the vat) followed by a mordant, and finally red and yellow dyes. That red could be madder or cochineal but I chose to use only madder, since that is what I am growing in the garden. My preferred yellow is weld. Each different combination results in a subtle variation. Some “blacks” are more purple, while others are a bit more green, or brown. I began using black walnut and cutch as a substitute for the madder and weld and sometimes added madder or weld to those. Each is a distinct hue, and definitely in the “black” family. I am confident of the lightfastness of these hues because of the primary dyes that have been used.

Dark indigo alone, on far left + combination of cutch and madder resulted in a neutral black

close up of “black” hues in the series on cotton and linen fabrics

These multiple shades of black, put me in mind of the paintings in The Rothko Chapel in Houston, which is the site of a series of large large “black” canvases by the artist, Mark Rothko. These black canvases are painted with layers of crimson, alizarin, and black.

But no exploration of black would be complete without some experiments using tannin and iron. Instead of building up layers of primary colors, I soaked the textile in a gall nut tannin bath, followed by a short immersion in an iron bath. I wanted to use as little iron as possible, but still achieve a very dark shade. I decided that 3% weight of fiber would be the limit of the amount of iron I would use.

Most often, I use ferrous acetate instead of ferrous sulfate because it is less damaging to the fiber. Cellulose fibers are are somewhat tolerant of ferrous sulfate so I did experiments with both. That is where I was most surprised! Without exception, the ferrous acetate resulted in deeper colors than the same amount of ferrous sulfate.

Why? I wasn’t sure. So I consulted my colleague, Joy Boutrup, who always knows these things.

“I think the reason for the grey instead of black with iron sulfate is due to the higher acidity of the sulfate. The acetate is much less acidic. The tannin complex cannot form to the same degree as with acetate.”

The pH of my ferrous sulfate solution was 4. The ferrous acetate was pH 6. (My tap water is from a well and is a slightly acidic pH6.)

The grey and blacks achieved with the tannin and iron are quite one-dimensional compared with those that result from a mix of colors and not nearly as interesting, Yet they are likely a more economical approach to achieving black; the multiple indigo dips, mordanting, and over-dyeing takes considerably more time and materials than an immersion in a tannin and an iron bath.

Always observing always learning, here in the mountains of North Carolina…

Natural Dye: Experiments and Results

A blog by Catharine Ellis

Dye Cards in a Box!

Black: An Improvisation