Top 5 Natural Dye Myths
Natural Dyes Are Not Colourfast
Sometimes someone will claim, “I dyed with blueberries/roses/purple cabbage, and it washed right out, so I know that natural dyes aren’t reliable.”
The fact is that effective natural dyeing is a skilled craft, requiring extensive knowledge of fibre types, proper fibre preparation, selection of actual dye sources (rather than the fugitive colourants noted above), and many other knowledge areas. For example, historically in European dye guilds, apprentices would study for 7+ years before being permitted to take charge of any aspect of the dye process.
Nowadays, no-one would claim that they tried to make a concert violin from popsicle sticks, and it fell apart the first time they tried to play it, so they know that carving violins from wood doesn’t work. Yet this is the assumption that some people make about natural dyeing because they haven’t invested any time in learning evidence-based techniques, and they assume that all claims made on the internet, and in many books sold as natural ‘dye’ books, are accurate. Finding factual information is key to success in this skilled craft. Recommended factual resources are provided at the end of this post.
2. Natural Dyes Don’t Give Vibrant Colours & everyone in the past wore drab
This is related to the first myth, above. It demonstrates a lack of knowledge of the facts and history of natural dyeing.
The reality is that humanity’s skills with coaxing stunning colours from plants, insects, lichen, and pigments goes back many tens of thousands of years. But if someone now attempts natural dyeing, without learning proper technique or which sources in Nature give reliable dyes, they are likely to get unimpressive results. But it’s not natural dyes that are to blame for that.
3. Salt & Vinegar Fix Natural Dyes
There are two primary ways that natural dyes form strong attachments to fibres…
Direct dyes can form strong molecular bonds to fibres on their own, without the need for a mordant. An example is Walnut dye.
Mordant/adjective dyes can form strong bonds with mordanted fibres. An example is Madder dye.
Mordants are metal salts. A metal salt is created when an acid reacts/bonds with a metal, releasing hydrogen in the process. Common metal salt mordants are aluminum sulfate (aluminum + sulphuric acid), aluminum acetate (aluminum + acetic acid), ferrous sulfate (iron + sulphuric acid), and ferrous acetate (iron + acetic acid). Metal salts form very stable bonds between natural fibres and natural dyes, in what are known chemically as ‘coordination complexes’, that render the natural dye no longer water soluble, creating stable colour results on our fibres.
Table salt (sodium chloride), while technically a type of metal salt, lacks the electrochemical properties necessary to form molecular bonds between itself, fibres, and dyes. Therefore, it is not a mordant. Seawater has been used historically in natural dyeing for various things, such as to clean wool, or to slow the absorption of dye by fibres, resulting in more even dye results (such substances are known as ‘levellers’). But it can not bond dyes to fibres.
Vinegar (acetic acid) is likewise not a metal salt, therefore it is not a mordant. It is only one half of what’s required to form a mordant, and lacks the metal component. Vinegar is, however, very acidic, so can be used in natural dyeing in many ways, for example to shift the pH of a dye bath to achieve a particular range of final colours. It can also be used as a solvent to create your own ferrous acetate, by adding small pieces of rusty metal to a jar of white vinegar and allowing them to react over the course of days/weeks. But as vinegar is not a metal salt on its own, it is not a mordant. It can not bond dyes to fibres.
4. 15%+ Alum Needed To Mordant Protein Fibres & add 50% more To Re-USe
7% alum tests
sequential dyeing with no mordant top up
Natural dye suppliers are in the business of selling product. Let me repeat that. Natural dye suppliers are in the business of selling product.
Most do not have anyone on staff with a science background, and do not follow the scientific literature on natural dyeing. Instead, their recommendations are usually based on habit, and on practices that encourage higher sales.
Higher mordant amounts can be useful in some natural dye methods, but for the majority of everyday dyeing, rich colour can be achieved with far lower mordant weight of fibre than most sellers recommend, and the mordant bath can be re-used many times without topping up.
For detailed citizen science tests of optimal alum weight of fibre, and of not topping up the mordant bath for repeat uses, go HERE, or click on the image above.
5. i want to avoid chemicals & dye like people in the past who used more natural methods
There is a notion that our ancestors lived an all natural life, never exposed to hazardous chemicals. There are several myths to unpack here…
Everything in the universe is made up of chemicals - some are hazardous to humans (for example, furanocoumarins), others ordinarily are not (for example, oxygen).
Not all hazardous chemicals are synthetic/manufactured. Many are naturally occurring in soil, plants, bacteria, etc. (for example, furanocoumarins are naturally occurring organic compounds found in several plant species that cause third degree burns and blindness on contact with the plant’s sap). Conversely, not all synthetic chemicals are harmful. Toxicity is primarily a product of the biological structure (at the molecular level) of a substance and of how it’s used, not of whether that biological structure was created in Nature vs. created in a laboratory.
Historically, people lacked the knowledge that science provides to us today, and often inadvertently used extremely toxic materials, many of them entirely naturally occurring. Reading through old dye manual shows that very hazardous materials - such as lead, chrome, mercury, and arsenic - were commonly used in ‘natural’ dyeing.
It is contemporary natural dyers, backed up by the extensive body of scientific evidence of which substances are hazardous to human and/or ecological health, and which are not, who can practice a more non-toxic approach to natural dyeing.
Recommended FACTUAL Resources:
Community: Natural Dye Education Facebook Group
Books:
Natural Dyes: Sources, Traditions, Technology & Science, by Dominique Cardon
Handbook of Natural Colourants, Editors Thomas Bechtold, Rita Mussak
Natural Colorants for Dyeing and Lake Pigments: Practical Recipes and their Historical Sources, by Jo Kirby, Maarten von Bommel, André Verhecken
The Art and Craft of Natural Dyeing, by J N Liles
Craft of the Dyer: Colour from Plants and Lichen, by Karen Casselman
Wild Colour, by Jenny Dean (the best book for beginners, but please find Jenny’s important proviso here)
The Art and Science of Natural Dyes, by Joy Boutrup and Catharine Ellis