Madder Roots, Harvest, and Comparisons

For  a number of  years I have been using  madder (Rubia cordifolia) sourced from Maiwa (in Vancouver, BC almost exclusively for my dyeing. I particularly appreciate  the fact that it is finely ground so that I am usually able to just put the dye into the bath along with my textile. If dyeing yarn, however, I typically will  place the ground dye into a net bag  to keep small particles of madder from physically attaching to  the fibers.  

I once heard Michel Garcia speak about the fact that you can nearly double the yield from madder root if it is finely ground. It makes sense. More surface area means that it’s easier to extract the dye. 

Early last year I harvested about 5 pounds of madder roots (Rubia tinctorium) from my garden. The plants were started  from seed and they had been in the ground for about 5 years. I dug up the entire bed (about 4’ x 8’), pulled up the largest of the roots, leaving the smaller roots in place. I amended the soil, added some chalk, and the plants have continued to grow in the same location. My theory is that I can continue to harvest every few years by  leaving the roots in the same place and repeating the amendment process  We’ll see…

I cleaned and dried the roots. Some of the dyes are developed by in the drying process so that is important.  A few weeks later, I dug up another small patch.  With this second batch, it occurred to me that maybe I could grind up the roots before drying them. It was easy to chop up the fresh roots into small pieces with an old food processor that I have designated for studio use. Once chopped, the roots dried very easily on horizontal screens.

Last month, I was preparing a major piece for an exhibition and I wanted to use my own madder. The large, dried roots proved to be problematic. I wanted to grind them as fine as possible but was not sure how to proceed. 

I tried a mechanical corn grinder. It was a terrible experience! The grind was very coarse, the roots jammed in the grinder, and it was not at all successful. I tried the old food processor – not powerful enough to be effective.  I even tried grinding small amounts in a dye-designated coffee/spice grinder. It was better, but still not very good and it would have taken far too long since the capacity of the grinder was very small. 

I did some research, and finally decided to purchase  a powerful electric grinder that is recommended for medicinal herbs (roots) etc. It was amazing! First, I quickly broke the roots into smaller pieces by hand, which allowed me to pull out the “chaff” (the stem pieces with no dye). I put the smaller root pieces into the grinder and I had finely ground madder root in just two minutes!

I’ve learned a lot (of course). Madder root, even when dried completely, still has elements (sugars maybe?) that coated the bowl of the grinder with a layer of sticky madder. The bowl of the new grinder cannot be immersed in water so I had to work hard to clean it out. But the madder is all ground and the grinder is  now ready to grind my dried sumac leaves and some other tannins. 

In our book,  The Art and Science of Natural Dyes, Joy and I discuss and show examples of how a dyer sometimes has more control over the color when using madder roots rather than extracts.  The source (and type) of the roots is also a factor.  Madder contains many different dyes and the two different species contain different combinations. 

As  I began my tests for the exhibition piece, I did many samples and used madder roots from a variety of sources.  The woven shibori project utilized mordant printing with different strengths of aluminum acetate, ferrous acetate, and combinations of the two mordants. When Rubia tinctorium is used with iron mordants, it is possible to achieve distinct purple colors. The purples are not possible with Rubia cordifolia, as the dyes within the roots are different. I was very happy to observe that my own madder was the very best of all!

madder comparison cotton
Ground madder root @ 50% w.o.f. on cotton with mordant printing. Left to right: Rubia tinctorium from my garden, Rubia tinctorium from France, Rubia cordifolia from India (Maiwa). Note the purples achieved from the Rubia tinctorium with an iron mordant.

 

 

Garden Series: Madder, detail of finished piece
Garden Series: Madder, detail of finished piece

I am very encouraged to keep growing…and dyeing….

I have begun using my own copy of The Art and Science of Natural Dyes in the studio and in my teaching. No, I do not have all of those recipes committed to memory! I have found it very useful to add tabs to the book, making it easy to navigate and find exactly what I’m looking for.

book

Note: Maiwa now carries very finely ground Rubia tinctorium roots.

 

 

Digging Deeper into a Single Dye – Madder (Rubia cordifolia)

I’ve been using a lot of madder. I have madder roots from my own garden and extracts on the shelf,  but right now I’m focused on the fabulous ground Rubia cordifolia from India that I purchased from Maiwa. It’s ground very, very fine. Charllotte tells me that it’s ground on a mill stone.

P1080247
Madder (Rubia cordifolia) on linen

Because the particles are so small, the dye is extracted more easily than from chopped madder root. The color is redder than I would expect from a rubia cordifolia. I love it!

Once the fibers are mordanted correctly I’ve usually been content to make a full strength dye bath. There is always leftover dye in the bath, which most often  gets turned into a dye lake. I didn’t have a full understanding of how much dye was actually in the dye pot or what  remained after the initial dyeing. In order to control my colors and  mix them effectively I needed a clearer picture of dye strength and hue.

I embarked on a systematic observation of the dye. The fiber was linen. It was treated with tannin and mordanted with aluminum acetate. I weighed out the total amount of dye that was needed for my various samples.  Typically I do 2-3 extractions in order to make my dye bath but this time I decided to continue extracting until there appeared to be no more color coming from the ground root. This took SIX 20 minute extractions! I realized that I had previously been wasting some of the dye.

The fabric was dyed with the extracted liquid. The amount of dye ranged  from 6.25% w.o.f. to 100% w.o.f. I also did exhaust baths of the dye.

P1080249
Madder exhaust bath, linen

Madder is an interesting dye because it contains so many different colorants. The alizarin is what gives us the red, but it also contains other colorants: yellow, orange an brown. The initial dye at each depth of shade was dominated by the red. Exhaust baths contained less  red, while the orange dominated. The colors obtained from the initial dyeing at 50% w.o.f. and 100% w.o.f.were very similar but the stronger bath continued to give me red before the color turned more orange.

madder % 1
Dye % range and exhaust baths

The test was repeated  on wool with similar results.

madder % 3
Madder % range on wool

Dye extracts are what drew me back into natural dyeing but I’m finding that working with plant material is far more compelling. Each plant and dyestuff is unique and since these are natural products they are subject to the changes in growing seasons and processing. Testing my dyes in order to understand the nuances is time well spent. It will make me a better dyer.