Winter Ink Making
(originally posted 2/2/21)
Dyeing, I’ve recently decided, is best done outdoors. Especially when printmaking with natural dyes, dry and sunny conditions are ideal to set and dry both mordant pastes and resist pastes. There are times that I’ve seen the result of a rice paste resist piece after an indigo dip and known from the result that I’ve missed a key ingredient: sun. Even if print pastes aren’t involved, I’ve learned since becoming a home owner and studying a bit of building science that it’s less than ideal to have large pots of warm liquid evaporating indoors for long periods of time. So the dyeing season is somewhat limited in my northern home, where the ground remains frozen from November to May, but I’ve found other ways of continuing my color foraging practice.
Homemade inks and watercolors. Cochineal, marigold, Maya blue, and indigo, plus their combinations
Traditional inks generally consist of two parts: a color source, an aqueous dye or powdered pigment, and a binder, which is usually a solution of animal hide glue or tree resin. Natural inks and paints are similar to natural dyes in that natural dye baths can be concentrated down to make an ink, or precipitated with alum to make lake pigments which can be dried, ground, and used to make all kinds of paints. Many pigments that can be used as ink on paper, however, will not truly dye a fiber. Some of these pigments can lightly adhere to the surface of a fiber with a binder (soy milk works well), but the color is not chemically bound within the fiber as with most traditional natural dyes. In other words: ink making really opens up a whole new world of potential color sources!
Natural inks, made from aqueous extractions and pigments. from left, wood stove char, oak gall and iron, pomegranate skins and iron, sumac leaf and iron, shale, mussel shell, Eastern hemlock, yellow birch bark, yellow birch catkin. My natural ink experiments don't always turn out super vibrant (see the yellow birch bark), but they are so easy to make that I feel more freedom in experimentation.
I love ink making as a practice of connecting to the landscape around me, much like dyeing, but on a smaller scale and with generally less mess and time investment. I feel more free to experiment with anything that calls out to me from the landscape, and I don’t need to gather nearly as much material as I do when dyeing. Because ink making doesn’t require much in the way of plant material or large equipment, it can be an easy practice to incorporate into a kitchen once in awhile, on a windowsill or near a wood stove for passive heating, and a great place to begin exploring color sources in the landscape. That being said, there are still some poisonous or poisonish materials that make great colors, and it is necessary to have designated ink-making pots, jars and utensils.
A passive heating method for natural inks
Ink making is less equipment-intensive than dyeing, and most items can be found around the house. These are the items I use in my process, most of these are optional or flexible.
Stainless steel pots or glass jars
The delicate chemistry of natural materials is affected by the material it’s heated in. Do not use iron, aluminum, or copper pots unless you’re specifically using their color-shifting properties. Small pots work well for ink making! If you don’t have an extra stainless steel pot, glass jars (also non-reactive) can be used with indirect heat sources (sunlight or near a heat source like a wood stove). Be aware that if you have very rusty lids, they could contaminate the color.
Mortar and pestle
(Optional, but recommended) Having a designated mortar and pestle for ink making materials is a good idea. The quality of your mortar and pestle will affect how fine you’re able to grind your material.
A small digital scale is very handy, though not necessary. Especially helpful for the fastidious notetaker
Water quality can make a huge difference! Filter your water if you’re on a municipal water supply, use rainwater (ideally) if you have a well.
Iron sulphate is used to make ferrotannic inks (most famously oak gall ink). This can be purchased as a greenish powder. Iron can also be foraged from rusty nails, or bought in supplement form at a drugstore.
Historical ink recipes generally call for animal skin glue or tree resin as a binder. The binder is the substance that carries the dye or pigment, improving structure, flow, and adhesion of the ink to the paper. I use a gum arabic solution, a product made from the dried and powdered sap of two acacia tree species, Senegalia (Acacia) senegal and Vachellia (Acacia) seyal. This is readily available online and is quite affordable. I am also interested in using a local conifer resin as a binder...more experiments to come!
I use whole cloves as a preservative to increase the shelf life of my inks and gum arabic solution. I've read that wintergreen oil can also be used.
Note: I do not recommend making iron-tannin inks with children! While iron is an essential mineral, it can be harmful in large amounts. Also, this ink can get very messy and will stain.
An assortment of natural inks, including the dark iron-tannin inks
When thinking about ink, the first color that comes to mind is likely black. While black is a challenging shade to achieve in the dye vat, it can be a simple ink to make. Soot or char inks have been made from a variety of materials and used as a pigment since prehistoric times; these include ivory black and other bone char, vine black from charred grape vines, and lampblack collected from oil burning lamps. The steps are simple: char any natural material you want to experiment with, grind to a fine powder (be sure to wear a mask of some sort!), and blend with a binder (I use a gum arabic solution, see recipe below). The char ink I’ve made tends to separate into particles on the paper, which I think is quite beautiful. Increasing the amount of gum arabic and grinding the particles finer will produce a more consistent ink.
Oak gall ink and other iron-tannin inks were the most widely used inks historically and, unlike soot inks, bind permanently to the substrate on which they're applied. Oak galls are formed on many species of oak tree when the gall wasp lays it's eggs in a budding branch, causing a protective layer to form around the egg, from which the wasps eventually hatch. The galls, which vary in size, shape, and density, are high in tannins. When combined with iron sulphate the tannic acid will turn black, forming a ferrous tannate complex. The ink will continue to darken on the paper as it oxidizes. Oak galls also vary in tannin content, as the papery thin galls I find in the northeast tend to yield gray tones when combined with iron, indicating that they're lower in tannic acid. Aleppo oak (Quercus infectoria) galls were known historically to produce the finest black ink. There is a great blog post by Catherine Ellis here that shows a comparison among white oak, red oak, aleppo oak, and tannic acid extract on cloth, demonstrating that not all oak galls are equal in their tannic acid content.
The paper-thin oak galls I usually find around my home in New Hampshire.
The chemistry here is one that I apply often in dyeing fabric. I use iron and tannins in conjunction to create prints on cotton and silk, and I use a low concentration of iron to shift colors as either a pre- or post-dyeing treatment. Iron and tannins are not ideal for creating solid blacks on cloth, however, as excess iron can make fabric brittle and eventually begin to deteriorate it. Historically, more stable solid blacks were created on cloth by layering various dyes with tannins and mordants.
Beyond the oak gall, tannins are easily found in many plant species, where they play a role in defense, sometimes as a pesticide, and may help in growth regulation. Tannins are astringent, and found in food and drink that leave the mouth feeling dry, like coffee, tea, wines, and hard cider. Once you know what to look for, tannins are easy to find in your surroundings. And once identified, they can be used with iron to make ink!
I recently made three different iron-tannin inks, using my local oak galls, pomegranate skins (not local, but salvaged from my compost), and dried sumac leaves from last summer. Sumac leaves are my preferred tannin source for dyeing as they are so prolific and locally available. Also, some folks consider them rather weedy and are happy to have you gather on their property :). Curious if a plant contains tannins? Simply take a small sample, brew in hot water for an hour or so, then add iron. If it turns dark, it's likely a good tannin source!
Ink made from pomegranate skin extraction and iron.
Once your tannin source is identified and gathered, place your material in a stainless steel pot and soak it in warm water overnight, or for a few days. It helps to grind dried material or break up fresh material into small pieces. I crushed my dried sumac leaves beforehand, poured in just enough water to cover them, and heated the water on the stove to below a simmer whenever I was in the kitchen (mostly morning and evening) for three days. These solutions don't need too much heat, alternatively you could put plant material in a glass jar and heat it on a sunny windowsill or next to a wood stove, the key here is time. Once you feel you have a decent extraction (you'll notice the water has taken on some color), the material can be strained from the water. Sometimes I will heat this solution on low without a lid to concentrate it down a bit. The more concentrated the solution, the stronger your ink. Now it's time to add the iron.
The sumac leaf extraction before I added iron. I let this get quite concentrated.
You can purchase iron sulphate, it comes in a greenish granulated powder, easily online. I buy it as a powder so that I can control exactly how much iron I put onto cloth while dyeing, but iron is also readily available in many environments. My house is full of rusty nails, for example, which can be added to the tannin solution directly. Non rusted nails can be soaked in vinegar to create an iron solution. I've even used ground up iron supplements, sold in any drug store, as an iron source. Slowly add the iron sulphate powder, or rusty nail solution, to the tannin extract. Add just enough to get a satisfactorily dark color; adding excess iron will cause the ink to degrade cellulose paper more quickly.
Here are the proportions of materials I used:
Oak Gall Ink:
8.6 g oak galls (a few dozen, these are very light!), crushed with a mortar and pestle
2 g iron sulphate
10 g gum arabic solution
Pomegranate skin ink:
skin from 2 pomegranates (outer and inner layers)
8 g iron sulphate
20 g gum arabic solution
Sumac leaf ink:
30 g dried sumac leaves (a handful or two)
6 g iron sulphate
20 g gum arabic solution
Gum Arabic solution:
Mix 1 part gum arabic powder with three parts hot water. Stir as mixture thickens. Thicken solution with additional gum arabic if desired.
Black inks, from left, oak gall and iron, pomegranate skin and iron, sumac leaf and iron, woodstove char.
Once you have a satisfactory color, you're ready to bottle the ink. Small glass containers are ideal for inks, and should be sterilized by boiling for about 5 minutes. I throw a whole clove or two into each bottle, which can help to preserve the ink and keep it shelf stable. Inks can also be refrigerated.
the sumac leaf ink is a beautiful purple-black, clearly seen in this rinse water
I found a fountain pen and filled it with my sumac leaf ink, it writes beautifully!
The four "black" inks
For a few years now I've been looking at the world through color-seeking lenses, even when the landscape is nearly devoid of color itself. These cold winter months, when the forest's architecture is laid bare and snowy fields undulate in shades of white and blue-gray, are alive with even the smallest disturbances. My senses are heightened this time of year and, even while much plant material is buried under frosty blankets, I find it that much easier to observe the world around me. There are color sources in these landscapes, too, from old sumac berries, to fallen tree bark, to trees who are beginning even now to put forth new growth.