When Joy Boutrup and I were teaching at Penland earlier in the summer she told the story of “Monday morning bleaching”. In old European laundries there was a serious problem with an increased number of holes left in fabrics that were laundered on Monday mornings. During the rest of the week the problem was lessened.
The issue turned out to be iron pipes. Water that had been sitting in the pipes all weekend leached ferrous out of the metal pipes. When ferrous is combined with bleach, the fabric will be compromised, resulting in holes. Once enough water had flowed through the pipes the amount of ferrous was decreased and there was no problem the rest of the week.
I have just experienced a related phenomenon in my own dye studio. After being away from home and studio a week or more, I observed that the water coming out of the studio tap was dark in color. Did this have to do with our shallow well? Was there contamination?
I suspected iron and tested the water for ferrous by stirring a very small amount of gall nut tannin into the water. When ferrous and tannin combine, the water will turn black. This is the principle of gall nut ink, which is made from iron + gall.
Water from the studio cold tap was fine. There was no reaction whatsoever. But the hot water turned black immediately, indicating that there was likely a problem with my “on demand” hot water heater. A call to the plumber confirmed that after 10 years of use the heating element had likely deteriorated and the water was leaching iron from the housing of the tank.
I continued to observe the water. After running the tap regularly for two days the iron content was much less but still too dark to be acceptable for dyeing.
After 5 days the hot water seemed to be almost completely clear of ferrous – but not quite.
This was not a good situation for a dye studio and I was forced to use only water from the cold tap for all processes. Yesterday I had a new water heater installed. All water is now completely free of ferrous!
Soft acidic water is far more likely to dissolve iron in pipes or other sources. Hard, alkaline water won’t present as much of a problem. My mountain well water is very soft and close to pH 6, which is slightly acidic – the perfect water to leach any metal available. It’s a reminder that all dyeing begins with the water. Some mysteries in the dye studio can be solved by simply looking at the water.
This summer took me to the Textile Center in Minneapolis, where I was invited to have a solo exhibition of naturally dyed textiles entitled Natural Dye: Experiments and Realizations. The title pretty much sums up the way I work: testing, experimenting and finally bringing it all to a conclusion before beginning the next set of investigations.
The Textile Center in Minneapolis is a nucleus of textile energy. Also at the galleries this summer is The Power of Maya Women’s Artistry, a stunning collection of hooked rugs made by women in Guatemala using recycled cotton materials. Mary Anne Wise, the Wisconsin based rug designer who got this project started a few years ago, will be speaking at the Textile Center today, July 21, and a workshop will follow this weekend. The third exhibition on display is Naturally: A Natural Dye Invitational, which is a lively collection of eco-printed textiles done by members of the Minneapolis textile community.These exhibitions will remain in the galleries all summer.
Michel Garcia was at the Center last week as the first Margaret Miller Artist-in-Residence, a residency named for the founding director of the Textile Center. Michel taught two fully enrolled classes: Color From Plants, A Natural Dye Workshop and Natural Indigo Dye Vat. I had the opportunity to sit in on a day of the natural dye workshop. It happened to be the day the class was working with cotton.
Over the last few years I have had several opportunities to learn from Michel in both workshops and filming sessions with Natural Dye Workshop and Slow Fiber Studios. Each experience brings me a clearer understanding of process and I can never predict what I will learn.
Michel is a philosopher as much as a dyer and chemist. He invites us to think about chemistry, process, and cultural ideas – all at the same time. It is stimulating, hard work to sift through all that he shares. One is not always ready to hear his messages. During this day, I began to get a glimpse of the way in which mordants may be affected (and damaged) by both acids and alkalines.
The next step for me, after being in a workshop with Michel, is always to go home, experiment, and really learn the lesson for myself. I have been trying to grasp the reasoning behind sequencing of dye colors with indigo. Years ago I learned to make greens and violets by dyeing indigo over yellow or red dyes. In 2011 I heard Michel Garcia state that the indigo should always be dyed first. Only then should the cloth be mordanted and dyed with another color. But I continued to work as I always had for a while – it’s sometimes difficult to un-learn what we think we know!
Over time I began observing that when indigo was dyed over a yellow or a red, the initial brilliant green or purple often becomes duller as the indigo dye is neutralized. If indigo is dyed first, and other colors dyed over the blue, the colors remain stable. WHY? Is the mordant damaged? Is the dye damaged? Is the alkalinity of the indigo vat the culprit? Is it the vinegar bath that is used for neutralizing the problem? It’s a subtle difference but one that I was very aware of.
I made these observations on cotton, but does it hold true for all fibers?
I wanted to test both protein and cellulose fibers that were mordanted. Instead of using indigo, I would simulate the alkalinity of an indigo vat by putting a similar amount of lime (calcium hydroxide) in water. As with indigo, I would also neutralize the cloth in vinegar after it had been in the lime bath. All samples were initially mordanted at the same time and dyed in the same dyebath. Sample #2 was dipped in an alkaline solution prior to dyeing. Sample #3 was dipped in the alkaline solution after dyeing.
cotton dyed in weld
silk dyed in weld
from top to bottom
#1. Mordant, dye
#2. Mordant, dip in alkaline solution, neutralize in vinegar, dye
#3. Mordant, dye, dip in alkaline solution, neutralize
What I observed consistently on both cotton and silk is a lighter dye color after the mordanted fiber had been put in to the alkaline solution (sample #2), which would indicate that the mordant had been compromised. When the fiber was put into the alkaline solution after dyeing (sample #3) the final color was brighter than #2, but not as brilliant as #1. This brightening would be consistent with a calcium or chalk treatment of weld in the dyebath.
Wool was a slightly different story. In the past I have not observed there to be major color differences when layering colors with indigo on wool. Mordants attach to wool in a different way than on cellulose and even silk, which leaves the mordants less susceptible to damage by the alkalinity of the indigo bath.
Wool, dyed in madder
Wool, dyed in cochineal
from top to bottom
#1. Mordant, dye
#2. Mordant, dip in alkaline solution, neutralize in vinegar, dye
#3. Mordant, dye, dip in alkaline solution, neutralize
In the wool samples, #2 was nearly identical to #1. The alkaline treatment of the dye in #3 is consistent with the effect of pH and calcium on either of these dyes.
Conclusion: the mordant on cellulose and silk is very likely damaged by the alkalinity of the indigo vat. In my own practice, I had already shifted my sequence of colors when using indigo in combination with other dyes. Now I believe I understand more clearly why it is important. Cellulose and silk fibers, especially, should always be mordanted AFTER dyeing in indigo. Both the tannin and mordanting processes are acidic and will assure a thorough neutralization of the alkaline from the indigo. Although it may not be as important with wool, this same sequence may give the dyer more control over the final color.
I welcome the opportunity to teach a workshop, especially when it will teach ME something new.
A few days ago I taught Dyes from the Local Food Co-op at Cloth Fiber Workshop in Asheville. The class came about when I was measuring some herbs and spices at our local food co-op. I noticed that a number of the dried materials in the glass jars were the same as the dye plants I was using in my studio: buckthorn bark, annatto, chamomile, and dock root. Obviously, the co-op was not stocking these substances for dyers, but….. it caused me to think about the multiple uses of these plants. For many years I have been taking a tincture of Isatis tinctoria, or WOAD, prescribed by my Chinese medicine doctor. How much overlap would I find between the dye and culinary/medicinal plants?
After taking an inventory of the materials available at the local co-op I decided on a collection of plants for this class. The criteria for the dyes included the following:
Each plant has some historical reference as a dye plant, and is preferably included in Natural Dyes: Sources, Tradition, Technology, and Science by Dominique Cardon.
Each has an alternative use, such as medicinal or culinary.
St. Johns Wort dye
“finishing off” the dye process
samples ready for cutting
Not all of these dyes are excellent performers. For reasons of poor light fastness or wash fastness I would not choose to use many of them in my regular studio work. But each dye has a story and may have been used throughout history because of its striking hue, availability, and/or affordability, despite a poor performance as a color over time.
Some of the dyes have been assigned a Natural Color Index Number (CI#). This is a reference database of color hues, names, and products maintained by the Society of Dyers and Colorists and the American Association of Textile Chemist and Colorists. It includes both synthetic and natural pigments. The inclusion of these natural colorants confirms the important historical reference and unique quality of their colors.
ferrous acetate comparison – photo by Kimberly Coyne
Sassafras bark – photo by Kimberly Coyne
fermented buckthorn bark dye, photo by Kimberly Coyne
Our dyeing was done on silk fabric. Some dyes required mordants, while others did not. Some roots and barks required alcohol extractions, while others extracted in water. Some dyes were affected by alkalinity. Others contained tannins and were altered with ferrous acetate. Alternative sources of the same plant resulted in color variations, suggesting that different parts of the plant were used, or possible changes in the growing season or drying process. When appropriate, we used alternative methods of dyeing such as a one-bath acid dye or fermentation.
Woven Shibori has been printed and is on the shelves of your favorite bookseller (also available at Amazon). I had some of the first copies delivered to me while teaching natural dye with Joy Boutrup at Penland School of Crafts. It was a fitting place to receive the first books. Joy has helped me over the years to understand the chemistry of natural dyes, various finishing processes, and textiles in general. I could not have completed even the first version of Woven Shibori without her input.
I love teaching at Penland! The studios are beautiful, thoughtfully cared for, and well supplied. Our students were fabulous and ready for whatever we brought to class. We focused on experiments, observations, and clarifications. The class worked with all natural fibers, and processes included dyeing, printing, and discharge. We were focused on WHY things happen rather than simply how they are done.
Every time I teach with Joy, I walk away feeling that I’ve taken a a class as well. We learn from each other as we solve problems, observe results, and identify the best practices for the studio.
So here is one of the things that FINALLY became clear to me.
I’ve heard/read for years that if animal hide glue was added to the indigo vat, then it would be better for wool or other protein fiber. But WHY? That had never been explained. Did the glue coat the fiber in some way?
The organic sugar vats, that I learned to make from Michel Garcia, use sugars from fruit or plants to create the reduction. Lime (calcium hydroxide) provides the alkalinity.
The vat begins with a quick reduction that eventually becomes a fermentation vat. These vats require a very high pH (about 13-14) in order to start the reduction. If the pH is too low the vat will not reduce. But it does not need a high pH to stay in reduction or for dyeing. A pH of 10 is more suitable for dyeing wool, while cellulose fibers do better with a higher pH of 11. The vat will eventually get to a pH 10 as the sugars create lactic acid in the fermentation but this could take a long time. I’ve had vats take weeks to reach pH 10.
The addition of dissolved animal hide glue (a protein) to the vat will gently lower the pH by absorbing some of the excess lime. The glue will precipitate to the bottom of the vat along with unreduced indigo and sugars. Joy also suggested using natural gelatin (another protein) as an alternative to the glue but we did not have a chance to try this.
It’s very important to insure that the vat is fully reduced before adding anything that will lower the pH. I would wait at least a few days after making the vat before doing this.
I’ve had dyers tell me that the addition of the glue does indeed improve the hand of wool fibers. How much glue? I’m not sure. We started by using a recommendation by Michelle Whipplinger in her Natural Dye Instruction Booklet. She suggests using the equivalent of approximately 1% fiber weight. The glue needs to be dissolved in water. That seemed a reasonable place to start. The key is to watch the pH and observe with both the eye and the hand.
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.
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.
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.
The test was repeated on wool with similar results.
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.
The new edition of Woven Shibori, (Interweave Press) – with a focus on natural dyes – is at the printers right now and will be available by late June! It’s exciting to see the cover and the layout complete. I first wrote Woven Shibori in 2005 and it sold out several years ago. The book has introduced weavers to the concepts and specifics of weaving fabric with woven resist patterning. When the book was originally written I was using many different types of synthetic dyes and layering them in order to accomplish rich color surfaces.
I have now been using natural dyes exclusively for 8 years. My challenge was to develop methods of resisting, mordanting, mordant discharging, and cross dyeing to create unique fabrics that have all the elements I love: texture, color, woven structure, and always some surprises. The natural dye palette and processes not only rival, but I think surpass, the effects I was achieving with synthetic dyes.
Red samples: mordant printing, dyed with madder, lac, and quebracho
Sequencing dye and resists: wool, dyed with indigo and black walnut hulls.
Cross dyeing effects, woven of wool and cotton, dyed with indigo and lichen
Cross dyeing: fabrics woven of wool, cotton, silk, dyed with indigo and madder
Mordant printing, mordant discharge, dyed with indigo and pomegranate
Indigo variations with woven shibori
mordant printing, dyed with cochineal
Mordant printing, dyed with osage and weld
Last week I taught a class on cotton printing with natural dyes at Cloth Fiber Workshop in Asheville. I was reminded once again why I teach and why I have written this book. It is gratifying to work with people who are curious, skilled (or not), and eager to learn more. The students in my classes keep pushing me to increase my own knowledge, to better understand what I do know, and to clarify my reasons for working with natural dye.
I would not be the dyer I am today without my own teachers and mentors. Michel Garcia of France and Joy Boutrup of Denmark have been guiding influences. They are both curious and knowledgable and have inspired me to continue down this path. Michel and Joy are also generous teachers. None of us can do this by ourselves.
Michel Garcia, coming from the dye garden in Lauris, France
Joy Boutrup,mixing indigo print paste at Penland School of Crafts
Although Woven Shibori includes lots of technical information about weaving fabrics for shibori, the dye information should be of interest to anyone who combines resist techniques with natural dye on their cloth.
Studies in green textures: mordanting printing, indigo, and woven resists
The Surface Design Association News Blog just published a piece I wrote on dyeing. Here is the link. The transition from synthetic to natural dyes and ingredients took some time, a lot of thought, and some real determination. I have reached the point of no return…..