Saturday, August 5, 2017

Thoughts on Printing and Dyeing with Botanicals Part 1

Pat Spark, © August 5, 2017

I love dyeing textiles, doing various surface design techniques to create interesting patterns on the cloth. I actually love to dye with synthetic dyes because of the amazing colors a person can get. Back in the late ‘60s, I did do a lot of experiments with plant dyes, but I could only afford what I could gather and these plants provided me with an assortment of beiges, browns, and ochres. Not the colors of my heart. 

Then Earthhues made extracts available to the public and plant dyeing became easier. But by this time I was hooked on using synthetics and even though I took some workshops on using extracts, in the ‘80s and 90s, I stayed with the various synthetic dyes I had learned to mix and control.

Fast forward to 2010. I began seeing textiles with images of leaves on them and people were talking about “ecoprinting”, a contact printing technique named by India Flint. While I had used a brayer and ink to apply pigment to leaves and then printed with them and I had pounded leaves with mallets to force the pigment out onto fabric, I didn’t know how folks were getting such strong leaf effects by a wet method. Finally in 2012, a learning opportunity presented itself to me. Pam DeGroot came to the Midwest Felting Symposium to teach “From Garden to Garment”- a workshop where we made garments using commercially made pre-felts and then we dyed these felt garments with plant materials using both contact leaf printing and natural dye immersion baths. This was my beginning with contact leaf printing and it was a fun addition to the years of dyeing knowledge that I had already accumulated.

Because I am primarily an audio learner, I learn best in a workshop and I take lots of workshops in a field I’m interested in to inundate myself with the information. I take copious notes in a workshop because they help me to remember what the teacher and the other students were saying in the class which also triggers memories of my own thought processes during the workshop- this is the influence of being an audio learner! I also do research and gather more information.  In addition, I experiment with the techniques until I feel comfortable with them.  But I also seem to learn best when I can try to find the universal aspects of the process I’m trying to learn.  Does this new thing I’m learning have anything in common with anything I’ve learned in the past? When I can figure out the skeletal structure underlying the techniques, it all starts to make more sense for me. I feel that I’m starting to figure out these basic concepts with botanical printing and dyeing so here is my attempt to write these things down. Although, the basic concepts will probably shift and expand as new ideas float into my mind. Also, as an artist and designer, I have found over the years that I design from the basics. It helps me to know why wool makes felt at a cellular level so that I can exploit those properties to have the felt turn out the way I want it to. I think of dyeing in the same way. 

Contact Printing Basics

The beginning idea of any contact printing is that you must have strong contact between the ground paper or cloth and the item you are using for the print. If you’re using a printing press, the press itself will provide the pressure to create the contact, but with leaf printing, the artist needs heat and moisture as well to get the pigments in the leaf to attach to the fibers in the paper or cloth. So you need good contact, heat and moisture.  Here is an overview of a method to do this.

1. Lay the leaves on the cloth or paper ground. (For this discussion, I am going to call the surface being printed onto, the ground.)
2. Put weights on one end of the leaf covered ground. Lay a core on the other end of the ground and roll up the leaf covered ground, pulling against the weights to get a tight roll with good contact. (The core can be rigid, like a pipe or piece of wood which must be cut to fit the dye kettle; or it can be flexible like plastic tubing, rope or rolled up paperboard, the flexibility allowing the roll to be curved around to fit inside a dye kettle easily.)
Maples in Center, no Dyes on Outside
Iron Blanket (Carrier) and Leaves Placed Sun Side Down
3. Place rubber bands on the bundle to keep it from unrolling and then use strong cord and tightly wrap it around the bundle so the leaves will stay in good contact with the ground. (A variation on this is to secure the bundle with rubber bands and then wrap it with PVC shrink wrap film. Wrap cord around the bundle and the heat of the printing process will cause the plastic to shrink and force the leaves into good contact with the ground.)

Now the bundle needs heat and moisture so that the pigments can release from the leaves and transfer to the ground.

4. Immersion Method-The bundle can be placed in water and simmered from one to several hours, depending on the leaves. People often put plant material or extracts into the water and if the ground on the outside of the roll is exposed to the bath, it will take up color from the bath. The ties around the bundle act as a resist creating lines where the ground cannot take up pigment. (A variation on this is to have a wide ground cloth and place the leaves only on a narrow strip of it. Use a core that fits that narrow strip of leaves, then roll and tie just that narrow strip. The rest of the ground is loose and untied. This loose ground will dye with the pigments that are in the bath, creating stripes of color beside a stripe of printed leaves.)   

Sumac in Center, Logwood on Outside

If the ground cloth is covered with a layer of plastic after it is rolled but before it is tied, no pigment can reach the ground and it won’t be able to take up any dye from the bath.

5. Steaming Method-The bundle is placed on a rack above boiling water and the steam creates the moisture and heat. With this method, no pigment will be able to dye the outside of the bundle. Again, the steam moisture is applied from 1-several hours depending on the leaves. (A variation on this is to solar steam the bundle by moistening it, wrapping it in black plastic and putting it in the hot sun for several hours or even several days. This is sort of a combination of the immersion and steaming methods. Some people put the bundle into a jar of water and set that in the sun which is definitely an immersion technique.)

6. Unwrap the bundle when it is cool, but let the ground dry and put it aside to “rest” for a few days before it is rinsed to help the pigments to “set”. 

Altering the Basics

Preventing Ghosting
After doing a print or two, I noticed that what worked well with a thick cloth like felt, didn’t work well with a thin cloth like 8mm1 silk.  The thinner the fabric, the more likely a “ghost” image would appear which was disconcerting when I hadn’t planned on it. The pigment in some leaves is so strong that it would penetrate through several rolls of the thin fabric, making prints that were less and less dark with each subsequent roll. To prevent this ghosting, I now lay the ground out on a piece of plastic drop cloth (1ml). This plastic rolls up with the ground and acts as a resist to keep the pigment in just one layer of the bundle.  I have also used densely woven cotton cloth for this. 

The Colorant Source (Leaves, Bark, Insects, etc.)

Botanical Colorants fall into three basic types: Substantive, Vat and Adjective. They are classified by their chemical composition. Substantive dyes don’t require any additional chemical additives because the dye molecules attach themselves to the fiber molecules directly. These types of dyes are relatively permanent. Familiar substantive dye sources are turmeric, black tea, onion skins, walnut hulls, oak galls, lichens and cochineal bugs.

            Vat dyes create a bond with the fiber through reduction and oxidation. They are introduced onto the outside of the fiber while in a reduced soluble form and then through oxidation they are converted into an insoluble form. Indigo is the most familiar type of natural vat dye.

            Adjective dyes require a mordant to create the chemical bond with the fiber. Many of the botanical sources we use are in this category. The various mordants will create different affects. A mordant molecule actually attaches to the fiber molecule and creates a bridge for the dye to attach. 

            Eucalyptus is an interesting botanical dye source that doesn’t fall nicely into the above categories. It has both a pigment molecule and its own tannin which is a mordant source. The leaves, bark and branches all give color just by themselves!

In addition, some dyes require modifiersA common use of a modifier is to change the pH of the fiber and cause the dye to change in some way, often to change in color. Vinegar will make the fiber more acidic while chalk will make it more alkaline.2, 3, 4, 5

            I highly recommend the video of Olga Kazanskaya for her explanation of dye plants and the specific pigments to be found in them. This list is in the PDF that goes along with the video. You can get it here:
 The Leaf Itself
When a leaf grows on a tree, its upper side needs protection from the elements. It is often more waxy and dense. This part of the leaf, the cuticle and upper epidermis, helps the leaf hold in moisture. The lower epidermis is more open, allowing for gas exchange. The middle layers of the leaf are spongy and are where most of the various pigments are located. People often call the top of the leaf, the “sun” side since it faces the sun.  They call the bottom of the leaf, the “moon” or the “earth” side. I don’t understand calling it the moon side since it doesn’t face the moon, but it does face the earth so I use this name.
            The pigments from most leaves will print only from the earth side. Some, like eucalyptus, will print from both sides. If a leaf is placed with the sun side against the ground cloth, any tannins in the leaf might squeeze out a bit around the outside edges. Because tannin reacts with iron to make a dark grey or black, it is possible to make a dark outline of the leaf if you add iron to the process somewhere. Sometimes even the veins of the sun side will make a tannin line. Where the leaf is cut from the branch can also leak tannic acid if that leaf has tannin in it. This can create an interesting halo of white where the tannic acid bleaches out any pigment in the background. If iron is present, it can make a big, dark blob, sort of like an ink spot. Some people cover the end of the stems with plastic wrap or duct tape to prevent this from happening.

Leaves can be used fresh, they can be dried or frozen. It is helpful to presoak the leaves in very hot water for about 10 minutes, even if they are fresh, to open them up so more pigment can come from them. This is especially important for dried leaves. Also, my experience with frozen leaves is that the cells are more broken down from the freezing and thawing process so they usually print nicely. The unfortunate thing is that they can take up a lot of space in the freezer!

Kathy Hays has a good, free document on harvesting and storing leaves.

The Fabric Itself
I usually buy fabric or scarves that are PFD. That is Prepared for Dyeing. Some people recommend that these should be scoured anyway, but since I am mainly using silk, I don’t bother. When I have used cotton, especially recycled garments, I do scour and wash them.

I do soak the fabrics really well before I print on them. With silk, I put it in water for about 8 hours, while with wool felt I soak it for a good 12 hours.

I have just started pre-mordanting my fabrics. I am using Aluminum Sulfate and I follow the instructions from Maiwa.
I did this because I wanted to get nicer yellows from the plants and alum will do this.

I have also pre-mordanted with tannic acid by dipping the damp fabric into the tannin prior to dyeing.

People also mordant by rolling the bundle with a copper, aluminum or iron pipe or by using a copper, iron or aluminum kettle for doing the dyeing.

Both tannin and alum can be added to the process at a different stage.  The list below for adding iron, could also be used for added alum or tannin. 

Adding Iron
Because iron can create such interesting effects with tannin, I often add it at different times in the process. I don’t pre-mordant with it however since it does sadden (darken) colors and I don’t usually want this as an overall effect. I prefer targeting the areas where I want iron and just putting iron in those places.

I do add iron in a few different ways:
1. Dip or paint the leaf with iron solution. Blot it before using.
2. Soak the leaves for a few hours in iron water. Blot.
3. Use a carrier that has been dipped in iron water.
4. Roll the bundle around an iron pipe.
5. Roll bits of iron (nails, wire, flat objects, etc.) in with the bundle.
6. Dip the piece in iron water after dyeing.

I use two forms of iron, ferrous sulfate in powdered form and ferrous acetate in liquid form. I make solutions of iron water. Ferrous Sulfate water is made from putting 2 tsp. of ferrous sulfate powder into a gallon of water. To make Ferrous Acetate, put a rusty nail or other rusty bits into a jar and cover with vinegar. Let it sit for several days until it is a bubbly liquid. Dilute this iron acetate liquid with water (about 5:1) and use it for the iron water.
            The iron water solution can be diluted if you want the reaction with the tannin to be less black.

Using a Carrier (Blanket)
A carrier cloth is a way of transferring (carrying) a dye, mordant or other additive to the cloth you are wanting to dye.  This “cloth” is often dipped, soaked or simmered in the substance and then placed onto the project. Then the sandwiched cloths are bundled and steamed, often with leaves between them to create botanical prints. The steaming transfers the new substance over to the cloth in your project.
            The cloth doesn’t have to actually be “cloth” at all.  Some people use paper towels for this. And the carrier doesn’t need to cover the whole project.  Potentially, you can cut out shapes and place them over your project in order to get some areas with the carried substance and some areas without it. For instance tannin and iron create a greyish black. So in theory, the project could be iron mordanted and shapes could be cut out of a tannin dipped carrier and laid onto the iron mordanted project.  After bundling and steaming, the areas where the iron and tannin come together would be a different a greyish black.
            The concept of using dye carriers (blankets) is common to many dyeing styles, both natural and synthetic dyeing. The iron blanket is one kind of carrier, but there are others. You use a material which can hold the mordant, dye or additive. This material can be something like cloth or strong paper which won't react with the substance that it is carrying to the cloth that is being affected. Or it can be a material that does react but during the heating process will still transfer to the other cloth. If you put something that will resist the transfer process between the cloth and the carrier, you can get areas on your cloth where there is no reaction between them. This is what happens when you place leaves between the carrier and the base cloth. Of course, depending on what substance is on the carrier, the carrier can react with the pigment in the leaves too. It's all about experimentation.
            You can also use other kinds of carrier cloths dipped or dyed in other substances than iron such as tannin, copper, alum, or even natural dyes like madder or cochineal. You can even use two silk scarves as each other blankets, with leaves or other resist designs in between, with each scarf pre-dipped in mordant or dye. This way you can get two scarves with one bundling! It is fun to experiment and try different substances with carriers. The carrier is just a way to add a substance onto the surface of the textile you are printing onto. It can be put over the whole surface or it can be cut out and put in just special spots.

1 Mommee (mm) is a weight measurement. The higher the number, the heavier the cloth. It is measured with a specific size of cloth (I can't remember the size). So if a silk cloth weighs less but still is the same size as another piece of silk, the actual threads themselves are probably smaller in diameter. In addition, the cloth might be more open. It is a traditional way of measuring silk. Many people think the mm stands for millimeter, which it doesn't. Some of the silk gauzes are 3-5mm. Habotai is often 5-8 mm. Because of the way crepes and satins are woven, they can cram more threads together than they can with habotai so they will usually weigh more and be more opaque.

2 Paula Burch has an article on pH changing additives here:   ATTN: Paula, like me, does not dye with only natural dyes or only synthetic dyes. She understands the chemistry of them both, thus this explanation pertains to them both. In this article she does not address the use of chalk in natural dyeing, but she does address the chemistry involved in using vinegar to make a dyebath more acidic.

3 Paula Burch has more information on natural dyeing here:   She includes several links to pages with mordanting and other natural dye information.

4 Here is an interesting list of mordants and modifiers from Griffin Dye Works.

5 Very good website with information on mordants and modifiers.


If you are interested in learning more about botanical printing there are many places online where you can sign up for workshops, download tutorials or ebooks, or buy books. Here are some of them, as of the date of this blog: 

Some Online Classes/Tutorials for Learning Botanical Printing
Justine Aldersey-Williams: 

Kimberly Baxter Packwood: 
not botanical printing exactly, but great info on surface design with natural dyes. 
downloadable ebooks: 

Nicola Brown online class: 

Fiber Art Now Magazine 
free downloadable PDF: 

India Flint 

Kathy Hays:

Olga Kazanskaya 

Terriea Kwong: 

Louise Upshall: