By Thea Haines and Rachel MacHenry
Magazine Issue: Spring/Summer 2014
Applying decorative colour obtained from natural sources—plants, insects and minerals—is an ancient practice, with evidence of natural colourants being found in textile fragments from as early as 2500 BC. The practice of dyeing and mordanting cloth was recorded by Pliny and Herodotus.
Textile trade was vital to Europe’s economy during the Renaissance and Enlightenment periods, and the cultivation, processing and manufacturing of fibres and dyestuffs played a crucial role. Exploration and colonization led to new sources of colour with the discovery of exotic products such as cochineal, indigo and logwood. Natural dyes were hot commodities, some so prized that they were more expensive than gold.
There was heavy trade in printed textiles from India, where skilled dyeing and printing techniques produced colourful cloth that was sophisticated and complex, far beyond anything produced in Europe’s printworks. European reconnaissance into Indian textile dyeing and printing techniques amounted to industrial espionage; scouts were sent to India to research techniques that could be replicated by European print houses.
In Europe during the mid-18th to mid-19th centuries, intense scientific and empirical research into the complex chemical and physical properties of natural colour was undertaken by colourists in these print houses, which resulted in natural dyes being used on an industrial scale. Dye-house colourists were highly valued and respected scientists, and their research can be linked to much of the understanding we have of colour theory today.
Scientific advancements that facilitated the large-scale use of natural dyes made way for the development of synthesized colour and had a broad impact on the textile industry in the form of mechanization and innovations in chemistry and pharmacy.
Interest in natural dyes and dyeing is currently undergoing a global revival. Fueling this resurgence is a growing awareness of the potential for harm from by-products of the industrial dye process and greater understanding of the environmental issues related to textile production.
Interest in local colour is evident in the spread of community-based dye gardens that seek to provide accessible natural dye information, such as the Textile Arts Center’s Sewing Seeds garden project in New York City. In this garden, dye plants are raised in an abandoned city lot, creating a community green space and providing dye material for project participants. As well, free workshops and tours offer local residents the opportunity to learn about plants, harvesting and extraction processes, and dye techniques. The educational mandate of such projects focuses on teaching the next generation about the many uses of plants not only as sources of food, but as sources of medicine, fibre and colour. At Sasha Duerr’s Edible Schoolyard in California, schoolchildren learn about raising fibre and dye plants; Duerr outlines a process she calls “garden to garment” to help children connect the plants they see growing with the clothing they are wearing.
A number of art and design institutions have recently established dye gardens, including the London College of Fashion in the UK and Sheridan College’s Craft and Design program in Oakville, Ontario, where a garden is currently under development. Campus gardens allow the entire process of growing, harvesting, processing and dyeing to be integrated into the curriculum, and give students maximum access to design and research opportunities.
Classical dye plant names evoke the global history of textiles: woad, madder, lady’s bedstraw and dyer’s broom. Unassuming common plants from our region yield surprising colour. Roadside goldenrod gives a range of greens and golds; black walnut hulls, considered so troublesome to the urban gardener, give rich deep browns, while sumac berries and oak galls both provide tannins used in the mordant process. The richness of this global plant record can be traced through a number of historical gardens, such as the wonderful Chelsea Physic Garden in London, UK (established in 1673), where dye plants from around the world are grown, or the recreated dyer’s garden at Black Creek Pioneer Village in Toronto, Ontario, which preserves the plants used by early European settlers to dye their home-grown clothing.
A number of North American designers and artists are becoming known for their use of natural colorants. Canadian Jolanta Prochnowski’s simple clothing collections for women are based on muted and sophisticated naturally dyed surface treatments, while Homefrocks, a New Mexico-based label, offers richly coloured garments with historic references. Mackenzie Frere, based in Alberta, focuses his art practice on a refined use of natural dyes in his hand-woven installation pieces while Brian Vu of Toronto creates interiors collections by over-dyeing military surplus with natural indigo.
The distinct qualities of natural dyes are part of their appeal. The associated historical narrative, the connection to raw materials, the capricious nature of each colour, and even the elaborate process of working them, all lend to the cachet and appeal of natural dyes.
The process of natural dyeing begins with mordanting, which facilitates the chemical bond of dye to cloth, increases colour permanency and enhances or alters the resulting hue. Alum, or potassium aluminum sulfate, a naturally occurring mineral salt, is the most commonly used mordant. It brightens plant dyes on all fibres and has been used in dye houses for millennia. Tannins, especially useful as a mordant for plant fibres, are found in many nut-bearing trees; those derived from the bark, acorns and galls of oaks have long been used in the tanning of leather. Oak-gall tannin combines especially well with iron to create more somber tones. Once fabric is mordanted, dyes can be applied either by direct applications such as hand-painting, stenciling or printing, or through immersion methods.
The richness of tone and harmonious colour palette produced by natural dyes can be credited to their molecular structure. Typically, synthetic dyes consist of a single colouring molecule, whereas most natural dyes contain several different colours belonging to different chemical groups. Madder contains as many as 18 chemically different pigments, and can produce a vast range of shades, ranging from pinks to corals, oranges, reds, purples, violets, browns and blacks, depending on processing conditions. Other dyes are highly sensitive to changes in pH; cochineal can produce as many as 60 different shades of red with differing pH levels. Natural dyes are not limited to use on textiles, but may be applied to any natural substance—leather, fur, bone, grasses and any protein or cellulose fibre. Diverse materials can be dyed together in one dyebath, resulting in an array of shades, as each fibre accepts the colour differently.
Thea Haines is a natural dye researcher and teaches textile design at Sheridan College in Oakville. Rachel MacHenry is a textile designer whose work focuses on sustainable artisan production.
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