A Practical Guide to Dyeing Wool from Local Plants
By Kiana Yoon
Approaching yarn dyeing as a hobby knitter for the last 3 years, I realized I took for granted the myriad of colours available for purchase across hundreds of yarn compositions. From muted pastel cottons to striking neon mohairs, one of my favourite parts of starting a project was finding the exact colour and yarn combination that would let a pattern sing. Dyeing yarn yourself allows you to reach another level deeper into the creative process behind designing with yarn but is also a rewarding practice of experimentation and accepting results as they come.
As a Plant Science student, dyeing yarn from plant materials for a more-than-human project for the Milkweed Co-Lab seemed like the perfect partnership of passions. The results are often what you would expect from the surface — bright yellows from goldenrods and purples from dark berries — but there are frequent surprises that made me marvel at the hidden secrets of the plants that surround us everyday. This process made me begin to look at the forest differently, wondering what colours would emerge if I let one plant part or another simmer in my steel pot for an hour — no doubt the beginnings of a long-term relationship to a new form of artistic experimentation taking root.
The following is meant to act as a practical guide to begin dyeing yarn from natural materials and a publishing of my personal findings from the process.
Much of what I’ve learned has come from the book ‘Wild Color’ (The Revised and Updated Edition) by Jenny Dean and Karen Diadick Casselman, who combined their decades of experience into an excellent introduction to the subject and an expansive colour-reference guide for many different species. Your local library is a great option to dive deeper into the subject as well as a number of blogs from experts (a brief list is included at the end). For a personal reflection on the process of learning to dye, it’s history, and connection to the more-than-human world, see this companion post.
Before You Begin
Dyeing Equipment
Much of the equipment required for dyeing may already be available in your kitchen but it’s important to never use the same pots or equipment for food preparation or storage. It’s best to purchase pots and other instruments second-hand reserved specifically for dyeing and label all equipment to avoid contamination. Beginners should prioritize a large pot and heat source, but I have listed additional equipment I found particularly helpful when starting out.
Large Stainless Steel Pot & Lid: Should be able to hold 14-18 liters of water to allow for more options for dyeing multiple skeins of yarn.
Large Bowls & Glass Jars: Multiple medium-sized bowls are useful for soaking yarn and plant materials before dyeing. Large glass jars are ideal for storing leftover dye for future use.
Long stainless steel tongs: To stir dyebaths and add/remove yarn from the pot.
Kitchen scale: Used to weigh plant materials and yarn to calculate the ratio of water dyestuff required for the amount of yarn.
Strainer or cheese cloth: Useful to drain the dye liquid from the plant materials. A cheese cloth may be necessary when dealing with finer plant materials.
Measuring spoons: For measuring amounts of mordants or modifiers added to the dyebath.
Heatproof measuring cup: To dissolve mordants and modifiers in boiling water before adding them to the pot.
pH strips: pH plays a role in the colour results and it’s useful to check on the pH of the water while working.
Mordant: Alum is a great mordant to start with to improve the dye colour and prevent fading. It can be somewhat hard to come by in stores but I found mine in a specialty health store.
Gloves: Helpful for handling yarn after mordanting or dyeing.
Yarn
For the purposes of dyeing, natural yarn fibers can be broadly divided into two categories: Protein (animal-based wool and silk) and Cellulose (plant-based cottons, linens, hemp, etc.). Natural fibers take better to natural dyes than synthetic materials, but the two categories require slightly different preparation methods.
For simplicity, I will focus only on animal-based yarns for this guide as they are more likely to provide the best results for beginners and do not require the additional preparation steps. Untreated wool skeins can often be found in craft or yarn stores made specifically for dyeing. It is important to treat wool with care and avoid friction during the treatment of wool to avoid felting. Raw fleece may also be a good place to start for felting crafts or to later be spun into yarn.
Water
Water is an essential part of dyeing, and its’ acidity or alkalinity will influence the result of the colour. Neutral water (pH 7) is usually considered the best for dyeing natural fibers, but some dyeing materials require specific pH levels to develop fully. Books and blogs are particularly useful for knowing where to start with specific types of plants.
The “hardness” of the water will also affect the final colour, referring to the concentration of minerals such as calcium and magnesium. Low concentrations of dissolved minerals, i.e. soft water, is preferred for most natural dyes (with noteable exceptions such as madder, weld, logwood, and brazilwood). For this reason, rainwater collected in plastic buckets is often preferred for dyeing, although in many places there is no guarantee it will be cleaner than tap water.
To change the pH of water, washing soda, ammonia, or ground chalk may be added to increase the pH while vinegar or lemon juice can bring the pH down. Rinsing and washing fibers should always be done with pH neutral water.
Health and Safety
Make sure all substances are handled with care, especially powders which can be dangerous to inhale in the powder form or as steam. Always know the safety concerns that come with the substances you're working with and prepare accordingly. For example, alum is an irritant and can be harmful if ingested. All work should be done in well-ventilated areas. Working outdoors using a camp stove or another heat source is advised but if working in the kitchen, never handle food at the same time. Gloves, eye protection, and long tongs or spoons are also advisable. Once again, all equipment that is used for dyeing should be reserved specially for dyeing and never used as cooking ware.
Scouring
Scouring or cleaning the fibers is an essential first step before the dyeing process can begin to make sure the dye can penetrate efficiently, more evenly, and last longer. pH neutral water is best for this process with dishwashing liquid or scouring agent.
Fill a pot or bowl with warm water and cleanser (about 1 teaspoon of dishwashing soap for every 6 liters of water). Let the yarn soak overnight, making sure the yarn is always fully submerged and can float freely in the water.
Remove the yarn and rinse in warm water. Wash and rinse several times then softly squeeze out the excess water and hang to dry. The drying process will go quicker if you roll the skein in a towel and press out the excess water before hanging to dry.
It’s possible to move from scouring to mordanting right away but make sure you have already determined the dry weight of your yarn with the kitchen scale or as marked on the purchased yarn.
Mordants
A mordant is used to help the dye remain permanently fixed to the yarn fibers. They are typically metallic salts such as aluminum, copper, and iron compounds that create a chemical bridge between the pigments and the fibers to create an insoluble complex. Many plant dyes may colour without the use of a mordant, but mordanting will produce stronger colours and slow down the fading process.
The most frequently used mordant is alum or potassium aluminum sulfate as it can be used on all fibers, inexpensive, and easy to use. Another aluminum based mordant is aluminum acetate which is more common for cellulose fibers. Copper and iron based mordants can also be used but are generally used more as a modifier to change the shade of natural dye colours. Below is a guide for mordanting with alum and cream of tartar. While the cream of tartar is optional, it can assist with the absorption of the alum and brighten or shift shades of some dyes on wool.
If dry, wet the weighed fibers by soaking them in water for a few hours. Squeeze out excess water before placing it in the mordant bath.
Fill a large pot with enough cool water to submerge the yarn with room to float freely in the water (above 30:1 water to yarn).
Dissolve cream of tartar in boiling water in a measuring jug (7% weight of fiber - 1 1/2 tsp per 100g of yarn). Stir well then add to the mordant pot.
Dissolve alum in boiling water in a measuring jug (9% weight of fiber - 2 tsp per 100g of yarn). Stir well then add to the mordant pot. Stir the mordant pot well.
Add the wet fibers to the mordant pot and heat slowly to a simmer and simmer for an hour. Stir the yarn frequently but gently so the mordant can absorb evenly, ensuring the yarn is always submerged.
Turn off the heat and let the fibers soak in the mordant pot overnight or at least a few hours, stirring occasionally. Rinse fibers thoroughly with cool water and leave to dry.
Once the yarn is mordanted it can be stored indefinitely and used for dyeing at any time.
Dyeing
Extracting the dye from the plants is always the most exciting part of the process and the step best suited for experimentation and play. Many factors will effect the dye that is extracted from the plant and how it will transfer to the yarn and can yield amazing variations.
In general, equal weights of plant material and yarn should be used to achieve a good depth of colour but I found that more is typically better. The part of the plant used will affect the best method for extracting dye colour before the yarn is added for absorption. Below is a general guide for extracting colour from different plant parts but there are often specific methods that will produce the best colour for the particular plant.
Flowers and Petals: Petals are delicate and will often produce the best colour with minimal processing and short periods in high temperatures. The most effective method for many petals is to pour boiling water over the flowers and let them soak overnight.
Bark and Twigs: Barks may need to be soaked for several days or weeks before simmering for an hour. Make sure to not boil bark as the tannins may dull the dye colour.
Leaves: Leaves may yield enough colour if soaked in cool water for several days or with boiling water poured over them and left to soak. Otherwise let simmer for one hour and sit overnight.
Berries: Berries should be crushed and then simmered for an hour.
Once the dye has been extracted and the liquid has cooled, the plant material can be strained out, and the dyebath can be used directly for yarn dyeing or saved for later use.
Before dyeing the yarn, make sure it is thoroughly wetted. Many plant dyes can be successfully applied to the yarn by simply letting the fibers soak in the cooled dyebath. This is particularly useful for delicate yarns such as silks or mohair that could be damaged under high heat. In general, hot dyeing is the most effective method for plant dye on wool but it can be worth trying without the heat first. For hot dyeing:
Add your dyebath to a large pot.
Squeeze the excess water out of the yarn and place into the dyebath.
Gradually bring the dyebath up to a simmer. Let simmer for one hour, moving the fibers around gently and occasionally.
Turn off the heat and let the fibers sit to cool in the pot overnight (except for most yellow dyes).
Remove the yarn from the pot (gloves are recommended) and rinse in cool water until the water runs clear. Let yarn dry out of direct sunlight.
With the basics down you’re free to take inspiration from your local fauna and experiment with different methods and modifications to the dyebath. For a starting point of common dyeing species and the most effective methods for working with them, see the following websites.
The first step to reshaping our connection to the natural world is knowing the names and forms of the species around us. Dyeing from plants — going out into nature searching for colour, learning the names and seasons in which certain plants grow, bringing them home and working alongside them — is a chance for both creativity and connection.
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