It is exciting to see such a passion for indigo these days, and especially the active exploration that is happening. With this also comes with a deeper understanding of indigo dyeing and process.
Vats reduced with chemicals such as sodium hydrosulfite or thiourea dioxide used to be the norm when I first learned indigo dyeing in the 1970’s. But now, many dyers have abandoned those chemical reduction vats and are returning to more benign processes. They are now making quick-reduction vats that are reduced with sugar, fruit, plants, or iron – thanks to the teaching of Michel Garcia. Some are growing their own indigo to explore fresh leaf dyeing and pigment extraction. Others are making sukumo – a long process of composting persicaria tinctoria leaves – Thank you Debbie Ketchum Jirik for offering an online class this past fall. Recently, Stoney Creek Colors has introduced a natural, pre-reduced indigo. And more dyers than ever are now exploring vats that are reduced by fermentation.
Fermentation is the process that has captured my interest in recent years. The long-term committment seems to fit my own “stay at home” life right now. The lower pH is suitable for all fibers. Most of all, it’s been an interesting adventure. Something that once felt out-of-reach has now become my preferred process.
The fermentation vat utilizes plant material to initiate and maintain an alkaline fermenting process, which causes the indigo to become soluble. During fermentation, plant material is broken down, creating bacteria. Lactic acid is produced, making it necessary to monitor the pH on a regular basis.
Madder root is a common plant material used in a fermentation vat. There is a long history of its use in indigo vats. It is usually combined with wheat bran, which ferments readily. There are many recipes in old manuals for this Madder Vat.
From The Dyer’s Companion by Elijah Bemis (originally published in 1815, Dover Edition, 1973)
for a vat of 12 barrels (not sure what a “barrel” is)
8 lbs potash
5 lbs madder
4 quarts wheat bran
5 lbs indigo
When I first leaned of these vats made with madder, I struggled with the idea of using perfectly good madder root to reduce an indigo vat. But I have now come to understand that these vats were most likely made with “spent” or “used” madder. I remember Michel Garcia talking about how the “used” madder from professional dye studios in the past was sold to the indigo dyers after it had been used to produce red dye. Indigo dyers have no need for madder’s red colorants and thus nothing was wasted.
So, I am dismayed each time I hear from someone who has made a fermented indigo vat using “new madder root”. “Spent” or “used” madder is every bit as effective as a fermentation booster as fresh or “unused” madder.
Most of the madder I use in the studio is in the form of finely ground roots, though chopped roots would work as well. When my madder dyebath is finished, I strain the ground roots and dry them for later use in an indigo vat. It’s that simple! And nothing is wasted.
Plant materials, other than madder, can be used in the fermentation vats. I frequently use dried indigofera leaves, as well as woad balls and have even begun a “hybrid “ vat using sukumo with indigo pigment. My most recent experiments have used both Dock root and Rhubarb root successfully. Madder, Dock and Rhubarb are all roots, all anthraquinones…..
I have used one-bath acid dyes extensively in my own work, especially for cross-dyeing my handwoven fabrics that are constructed of both cotton and wool. The acid dyes attach only to the wool or other protein fiber. When combined with indigo, which attaches to both cellulose and protein fibers, very interesting combinations can be achieved.
The “one-bath acid dyes” that Joy Boutrup and I discuss in The Art and Science of Natural Dyes include henna, madder, pomegranate, cochineal, lac, and rhubarb root. Since publishing the book, I have extended the palette with the addition of other dyes, mostly due to the help from Michel Garcia when he was here in my studio several years ago.
Michel and I were discussing dyes that I might choose NOT to use because of their poor tolerance to light. Alkanet is one of those. A purple color is extracted from alkanet root by means of an alcohol extraction. The color is beautiful and enticing , but very fugitive. Michel indicated that the alcohol extraction does some damage to the dyestuff.
The one-bath process extracts different dyes from the plant than from those that are obtained from using more traditional methods. While experimenting, we treated alkanet as a one bath acid dye (for protein fiber only) and a beautiful purplish brown color emerged that is quite fast to light. It’s a warm neutral color that I have not achieved using any other dye.
Safflower petals are another dye source that he showed me can be used as a one-bath acid dye. A golden yellow is dyed onto wool or silk that is quite lightfast and requires no mordant. The safflower petals can still be used after the one-bath process to extract the traditional reds and pinks by altering the pH, though the red colors are still not fast to light.
These discoveries energized my own work and as I went deeper, I began noticing that many of the plant dyes that are used for the one-bath acid process have also been used as natural hair dyes: henna, madder, alkanet, dock, rhubarb root, cassia leaves (Cassia obovata, also referred to as “neutral” or “colorless” henna). These can all be used successfully for one-bath acid dyes and result in very lightfast colors. Dried Indigofera tinctoria leaves (“black henna”) are also used as a dye for hair and when combined with henna results in a very dark color.
The application of henna as both a hair dye and as mehndi, (a temporary dye for the skin) is the same: finely ground plant material is mixed into a paste with water, acidified with lemon juice, and allowed to sit on the hair or skin for several hours. When the paste is washed away the color remains. These are considered non-permanent dyes for the skin and hair and may be repeated after the color fades.
Acid dyes are very lightfast but are not as fast to washing. (This applies to both natural acid dyes and synthetic dyes.) If applied to the skin or hair, they will eventually be washed away. BUT importantly, we don’t wash our woolen fabrics as aggressively or as often, thus the dyes are suitable for wool or silk textiles.
I was curious to see if these dyes could be used for direct application to woolen fabrics. There is a Moroccan tradition of using finely ground henna leaf in this way on fabrics woven of wool and cotton. It is well documented in the book Die Farbe Henna / The Color of Henna Colour of Henna: Painted Textiles from Southern Morocco by Annette Korolnik-Andersch and Marcel Korolnik.
I made a paste of each of these dyes using finely ground plant material with a small amount of water. I acidified the paste with vinegar (citric acid would damage fabrics that contained cotton) and allowed it to sit overnight once applied to the textile. The colors are strong and clear, although some dyes spread more than others. They are not quite as deep as those dyed in a heated bath, though steaming the textiles will result in deeper colors.
I have observed that the freshness and quality of the dyes matter. Organic henna, used for hair and skin dye, resulted in a bright clear color while other henna powders that I have used produced duller colors.
This approach has revealed to me one more way of understanding and using natural color and given me more opportunity to combining it with my own woven textiles. It has taught me more about plant categories, alternative applications, and the need to constantly be open to new ideas.
First of all, I know that my well water is acidic. It measures about pH 6.0 here in the mountains of North Carolina.The water is ideal for most dyeing. There is no iron or other minerals that might dull the colors. The acidity is another issue.
Most of the yellow dyes in my garden, or those that I might gather locally, are flavonoids. That means that they require a mordant in order to attach to the textile. No mordant means no yellow. It’s that simple. Some of the dyes may also contain some tannin or other colorants but the yellow is what we’re talking about here.
Last summer Joy Boutrup and I taught a class together at Penland School of Crafts, located near my home in western North Carolina. A student in the class was especially interested in gathering local plants for use as a dye source. She struggled to get the locally gathered dyes to attach to her textiles, especially onto mordanted cotton.
Joy had the answer-of course!
When the dye meets the mordant in a textile, an insoluble lake is formed. This lake is formed most readily in neutral or slightly alkaline conditions.
An alum mordant makes a very strong bond with wool but there is no chemicalbond between cellulose and the mordant. Instead, the mordant is deposited as an insoluble compound on the textile.
An additional issue is that many of our local plants are acidic. When the plants are boiled in our already acidic water, the pH of the dyebath becomes so low that the dye may struggle to attach to the mordant in the fiber. In fact, the mordant in the cotton can be damaged or even removed if the bath is acidic enough. This is exactly the reason why we don’t add an acid to a cochineal bath when dyeing cellulose. The mordant would be damaged and little dye attaches.
The remedy: Add a small amount of chalk (calcium carbonate) to the dye bath to neutralize the acid that is present. This will do no damage to the dye or the textile. Chalk is not an alkaline but will neutralize an acid that is present. Within reason, there is no possibility of having too much chalk and any excess will simply precipitate in the bath and rinse out of the fabric
Since my own broom (Genista tinctoria) is currently in need of a serious trim, I began a series of flavonoid dye tests with that and then compared other dyes from my garden and environs.
Broom is currently blooming in front of my studio
Broom, with and without chalk
I used all fresh plants at 300% w.o.f. and dyed both wool and cotton. The wool was mordanted in alum. The cotton was mordanted using tannin plus alum and soda ash. After making the dye decoction, I divided the dye bath in two equal portions and added both wool and cotton to each bath.Chalk was added to only one of the baths.
The results were quite surprising (but also very consistent) and made me realize that I have likely not been achieving the maximum amount of color from some of my local dyes.
The plants I gathered and used were
Broom (Genista tinctoria)
Wild grape leaves
Dyer’s Chamomile (Anthemis tinctoria). I used the flowers and after gathering a basket of the small flowers I tested the dye content in the entire plant.
Staghorn sumac (Rhus typhena) . We often think of sumac as a good source of tannin but the leaves, according to Dominique Cardon, are also rich in flavonoids.
Weld (Reseda luteola). This is my “go-to” yellow dye. I almost always use dried plants and I rarely add chalk with weld on cotton but frequently add it to a wool bath.
After boiling the plant material I recorded the pH of the decoction. The pH was measured again after the addition of chalk. Each dye bath was approximately 4 liters and I added about 1 TBS of chalk.
The chalk will alter the appearance of the bath from transparent to cloudy and nearly opaque.
The samples below are wool. Individual samples on the left had chalk added to the bath. Those on the right did not.
Dyer’s chamomile, whole plant
Dyer’s chamomile flowers
Broom, with and without chalk
In every case, I achieved deeper and brighter yellows colors when the chalk was added to the fresh plant baths. The only exception was dried weld, which was used at 50% w.o.f. When dyeing with the fresh weld plants, deeper yellow hues resulted with the addition of chalk. When I used dried weld plants, the chalk made very little difference. I asked Joy about this and she indicated that is was possible that some of the acids disappear in the drying process. It will require more tests and explorations to confirm this.
The cellulose samples are especially notable. The high acidity of some baths made without the chalk was enough to damage the mordant significantly. The grape leaves and the sumac, which were the most acidic, destroyed the mordant in the cellulose and only the tannins that are present in the leaf were able to attach and color the fabric.
If your water is not acidic, or has calcium in it, then these tests may not be relevant but the addition of chalk will never harm the fiber or the dye and may release more color.
I recently found the following note that I had made during a class with Michel Garcia several years ago referring to grape leaves:
“If they are too sour they will dissolve part of the mordant.” M. Garcia
My own notes continue to say:
After boiling the grape leaves the solution of a pH 4 – too acidic – it will remove the mordants. Sumac will cause the same effect. Boiling breaks the bonds of the tannins and gallic acid is released. Add chalk to the bath to decrease the acidity of the dye bath – you cannot be in excess of chalk.
Sometimes we’re just not ready to absorb information the first time we hear it. This is exactly why I continue to question, keep notes, and actively test and observe.
It’s summertime! Enjoy your yellow flavonoids!
Note: I purchase my chalk from a potter’s supply store. It is inexpensive and can be purchased in quantity. Potters refer to it a “whiting” and rarely refer to it as chalk or calcium carbonate. Do check the MSDS though, just to be sure.
Upcoming: On July 13 I am presenting a Zoom webinar, entitled Colors from the Garden, as part of the John C. Campbell Folks School’s Appalachian Traditions Series. You can sign up here:
Fora number ofyears I have been usingmadder (Rubia cordifolia) sourced from Maiwa (in Vancouver, BC almost exclusively for my dyeing. I particularly appreciatethe fact that it is finely ground so thatI am usually able to just put the dye into the bath along with my textile. If dyeing yarn, however, I typically willplacethe ground dye into a net bagto keep small particles of madder from physically attaching tothe fibers.
I once heard Michel Garcia speak about the fact that you cannearly 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 startedfrom 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 byleaving the roots in the same place and repeating the amendment processWe’ll see…
digging the roots
roots from the garden
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 beeffective.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.
Corn grinder was not an efficient way to grind madder roots.
resulting chopped madder
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!
In two minutes these whole pieces of root turned into a finely ground powder
Finely ground madder in the new grinder
I’ve learned a lot (of course). Madder root, even when dried completely, still has elements (sugars maybe?) that coated the bowl of thegrinder 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 isnow 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!
process and tests for the finished work
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.
Note: Maiwa now carries very finely ground Rubia tinctorium roots.
I have always enjoyed how the goldenrod grows and blooms alongside the purple asters – a beautiful combination of complimentary colors.Goldenrod (Solidago sp.) is a member of the aster family. There are many solidago species native to North America, and they can also be found in other parts of the world.
Goldenrod flowers, gathered in western North Carolina
Goldenrod and New England Asters, photo from Denver Botanical Gardens
Goldenrod and thistles, Newfoundland, CA
Is goldenrod a good source of dye? Yes, but with reservations.
Though it is not one of the “classical” dyes, and it’s lightfastness does not match that of weld, it was used as a locally available dye in North American and Europe. Dominique Cardon (Natural Dyes: Sources, Tradition, Technology, and Science) writes about goldenrod’s historical use, along with weld and Persian berries, to dye the yellow hats the Jews were required to wear in the south of France in the 13th century.
I’ve always readthat goldenrod does NOT dry well for future use – so I never tried to dry it. I can accept the fact that some dyes deteriorate in the drying process. Black walnut hulls are a good example.
A couple years ago I was teaching a class here in Asheville, NC on dyes that could be sourced from the local food co-op. I used dried goldenrod plant material, as it is used medicinally. It resulted in very good color. So I began to wonder….. CAN A GOOD DYE BE OBTAINED FROM DRIED GOLDENROD?
It’s one thing to read a statement about a plant – it’s another thing to know and understand that statement. Ihad never tried to dry goldenrod. This year I finally got around to doing my own testing.
I gathered fresh goldenrod, and used that to dye aluminum mordanted wool, silk, and cotton. There are many yellow dyes in goldenrod and they may include quercitron, isoquercitron, kaempferol, astragalin, isorhamnetin. Since the dyes in goldenrod are primarily flavonols, a mordant is required.
I dried goldenrod from that same harvest. Plants were hung upside down in a dry space with plenty of air flow. Only the flowering heads were used as a source of dye. I was able to accurately determine the weight of the plant before and after drying. 300 grams of fresh goldenrod flowers resulted in 100 grams of dry flowers.
I dyed with fresh goldenrod at 300% w.o.f, while the dried was used at 100% w.o.f. Because I knew the weight before and after drying, I was confident that I was using the same amount of dye, whether it was fresh or dry plant material.
The results: The dyes seem not to have suffered from the drying process. Careful drying is likely a key element. So yes, I will dry some goldenrod and I will complete lightfastness tests on all three fibers. The goldenrod will not replace the weld that I grow and dry each year, Weld will always be my primary yellow dye as that has proven to be the best, and most lightfast yellow dye. But it is good to know a bit more about the dyes from plants available in my neighborhood.
Thus far I have used only the flower heads for dyeing. Maybe next year I’ll experiment with the stems and leaves from the entire plant.
Last week I was a student in a class with local dyer, Dede Styles, at Cloth Fiber Workshop. Dede describes herself as a “heritage dyer”. She learned the craft from Mary Frances Davidson, another heritage dyer from our North Carolina mountain region, who wrote a book on the local dye plants. The Dye Pot, originally published in 1950, is still in print today.
Dede dyes mostly wool and uses only local plants that she can collect herself (with the exception of cochineal and indigo which do not grow here). Her knowledge of plants, local water sources, and seasonal growing patterns is exceptional. The dye plants she uses are very specific to this part of the country, though some are found in other areas. They are chosen because they give good color that lasts.
She carried buckets of her own “creek water” to the workshop rather than use city water from the tap and described how she can obtain a certain color with a particular dye using water from her creek. Water from “over the mountain” will produce a very different hue.
Dede dyes yarn in quantity, outdoors, using large stainless steel, iron, or copper pots. Her philosophy about dye amounts is to “cram as much dye plant material as possible into the pot”. After cooking, she strains the liquid. All the yarn for a certain project must be dyed at the same time in a single dye-lot since results are not exactly repeatable. As someone who measures everything carefully and precicely, this is a refreshing approach.
Straining sumac berries through a cotton cloth
Various dye plants, gathered locally
Dede Styles with yarns dyed with Black walnut bark
Fall is a good time to gather local plants. We observed what was growing around the weedy area near the railroad tracks, paying special attention to stands of goldenrod, sumac, and fall asters. Dede knows a lot. She told us that many people think they are allergic to goldenrod, but the ragweed that grows nearby is really the source of the allergens – goldenrod is only pollinated by bees, thus there is no airborne pollen! The white asters seem to produce more color than the purple fall asters, says Dede – likely because the purple asters grow in damper areas – and maybe the dyestuff is diluted. She pointed out the difference between sumac and the similar looking Goldenraintree, which contains no dye. Some plants are biennials and thus will only be found growing in the same area on alternate years. As we walked, Dede talked about responsible gathering of plants, and the damaging use of herbicides by roadsides and railroad tracks. Gentrification, she says, is the enemy of wild dye plants. Springtime, when the tree sap is running, is the only time to easily gather bark from a fallen tree. And of course, she wanted to be sure we knew the difference between Virginia creeper and poison ivy – neither one of these is a dye plant but they are often found growing together in the same vicinity as the dye plants.
Black walnut bark. Saplings are plentiful where the nuts have sprouted and need to be cut down regularly.
Goldenrod and white fall asters
Bumper sticker on Dede’s van
I hope that there are more “Dedes” out there where you live – people who know their plants from deep experience and observation and who are willing to share what they know. We owe it to ourselves to honor them and to learn from them. Dede told us that she is working on a book. It will be about the local Western North Carolina plants: where they grown, where to find them, and when to gather them responsibly.
Thank you Dede!
And a follow-up to my own earlier experiments with some locally gathered dyes – flavonoids. Some of them came from my garden (coreopsis, broom, chamomile, marigold, and weld) others from “the field” (black oak bark and goldenrod) and a couple were purchased (osage and Persian Berries). I dyed mordanted silk and subjected them to lightfastness tests. The weld from the garden will continue to be my “go-to” yellow dye.
Most of us working with natural dyes have no immediate tradition from which to learn or elders to teach us. We are re-inventing natural dye, trying to learn from books, teachers and other dyers who are willing to share what they know and, of course, our own experiences and mistakes.
Many of us purchase our natural dyes from suppliers in the form of extracts or dyestuffs that are grown and harvested in other parts of the world. In this way, we can access all of the classical dyes, such as indigo, madder, cochineal, weld, pomegranate, etc. These dyes do not necessarily reflect where we live or where we come from.
I was in Madagascar for two weeks during May for the International Festival of Plants, Ecology and Colors. Following the conference our small group spent time in a village in the northwest deciduous region. There we saw women harvest raffia from the local palm trees and wild silk from cocoons in the local mangrove forest. Natural dyestuffs are gathered in the immediate surroundings and are coaxed from the leaves, barks, resins, and fruit of local plants. The ONLY dyes available are truly local dyes, which the dyers gather themselves and about which they possess a deep knowledge of experience. Most of the plants used for dyeing are also used medicinally. Importing dyestuffs is not an option here.
The region is rich with sources of natural color, including reds from teak leaves, indigo from the local Indigofera erecta, gold and yellow from barks, and black from tannin and iron-rich mud. Wood ash and citrus fruit provide adjustments in pH when needed.
My own local environment does not have such range of color available in “the wild”, though I do maintain a garden of dye plants. I came home from this trip with a deeper understanding of what LOCAL color really means and now have a new resolve to identify local dye sources from my own immediate environment. No doubt, they will be variations of a yellow color since plants containing flavonols and tannins are in abundance.
I have already begun the dye experiments in the search of my own “personal colors”. All of the dyes will be put through rigorous testing for light fastness and wash fastness. In the end, I hope to identify one or two dye sources that are abundant and easy to harvest here in western North Carolina. Of course, collection of these plants must pose no threat to our environment.
Eucalyptus is not native to where I live but I have watched dyers (with a bit of envy) from other parts of the world use these plants as a source of color and tannin. Each year I grow a plant or two for experimentation. These experiments have led me to some interesting observations.
The variety commonly found at our local garden center is Silver Dollar Gum (Eucalyptus cinerea). A friend, visiting from Australia, fondly recognized it in the garden as “gummy”. It will grow as an annual here and I always dry the round “silver dollar” leaves for dye. Sometimes I can even acquire them amongst the floral arrangements in the local grocery store. This year I had a additional variety (Eucalyptus globulus). It was grown by a friend from seeds that she brought from a tree in her yard in Ethiopia.
Silver dollar gum (Eucalyptus cinerea)
Dye tests were done on wool, both with and without an alum mordant, using dried leaves at 100% of the weight of fiber. Plants contain many different colorants. In the case of the Eucalyptus leaves, they contain both a flavonol and a tannin. The flavonols are typically yellow in color and require a mordant to attach to the fiber. The tannins produce a variety of colors and do not require a mordant.
I placed non-mordanted wool fabric in the bath with the leaves. It was brought to a low simmer (approximately 190 degrees F). The color was slow to come but after about 2 hours the Eucalyptus cinerea resulted in a deep red/orange, while the Eucalyptus globulus turned a deep brown.
Alum-mordanted wool was dyed in a separate bath. The fiber quickly (within 30 minutes) turned a brilliant yellow from both varieties of eucalyptus. I removed some of the fiber from the dyebath when the yellow was still bright. As the rest of the fiber stayed in the bath, the tannins were released, changing the color of the wool from yellow to either a deep yellow/orange or a yellow brown. After two hours in the bath the mordanted fiber had been dyed by BOTH the flavonol and the tannin.
Several years ago I heard Michel Garcia say that the clearest yellow color from plants may come at the beginning of a dyebath, before any tannins are extracted. As the fiber stays in the bath with the dyestuff, the tannins are released and the color becomes deeper and duller. The eucalyptus is a dramatic illustration of this principle but other plant materials also indicate the same principle.
I have not yet completed lightfastness tests on any of these samples but they are in process. I would guess that the deeper, tannin-rich colors will be more lightfast than the brighter flavonols.
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.
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.