Monday, March 10th: The Chemistry of Dyes
The History of Dyes
Even before people began to spin yarn and weave cloth, they applied colored earth, plant saps, and juices directly to their skin: this was the first type of cosmetics. Women in Mediterranean region applied alkanet as rouge and lipstick and used chamomile and henna to dye their hair. Indians in South America prepared a paste of annato seeds for painting their bodies.
Among the ancient peoples, the Egyptians not only dyed textiles but also understood the use of mordants:
"In Egypt they dye clothing in a remarkable way. The white material is treated not with colors, but with mineral compounds which absorb the colors. This done, the materials appear unchanged, but when immersed in a cauldron of boiling dye and immediately removed, they are colored. It is remarkable that though the dye in the cauldron is of one color only, the materials when taken out are of various colors, according to the quality of the mineral compounds applied, and it cannot afterwards be washed out."
The Phoenician dye industry, begun in 15th century BC, was renowned for its Tyrian purple, or royal purple obtained from a species of shellfish processed in the city of Tyre, which actually produced a range of colors from red to violet to blue.
The Greece and Rome in the first century AD they used indigo and woad for blue, alkanet and madder for red, weld and saffron for yellow, and oak bark and walnut hulls for golds and browns.
In India, the dye industry began as early as 2500 BC. Dyers in India and southeast Asia not only mastered the art of producing bright colors on cotton, but also developed techniques for printing colors on woven fabric and making designs with resisting dyeing.
Colors often play roles more important than mere decoration or ornament: they serve as cultural symbols. Different colors may be associated with cosmic and religious forces, with status and class, with illness and health. In societies more governed by tradition, rules for using specific colors were much more strict; choice dyes from rare sources were reserved for the garments of the kings or priests; some colors of clothing were believed to protect the wearer from pests and diseases or from supernatural forces.
Among the ancient peoples, the Egyptians not only dyed textiles but also understood the use of mordants:
"In Egypt they dye clothing in a remarkable way. The white material is treated not with colors, but with mineral compounds which absorb the colors. This done, the materials appear unchanged, but when immersed in a cauldron of boiling dye and immediately removed, they are colored. It is remarkable that though the dye in the cauldron is of one color only, the materials when taken out are of various colors, according to the quality of the mineral compounds applied, and it cannot afterwards be washed out."
The Phoenician dye industry, begun in 15th century BC, was renowned for its Tyrian purple, or royal purple obtained from a species of shellfish processed in the city of Tyre, which actually produced a range of colors from red to violet to blue.
The Greece and Rome in the first century AD they used indigo and woad for blue, alkanet and madder for red, weld and saffron for yellow, and oak bark and walnut hulls for golds and browns.
In India, the dye industry began as early as 2500 BC. Dyers in India and southeast Asia not only mastered the art of producing bright colors on cotton, but also developed techniques for printing colors on woven fabric and making designs with resisting dyeing.
Colors often play roles more important than mere decoration or ornament: they serve as cultural symbols. Different colors may be associated with cosmic and religious forces, with status and class, with illness and health. In societies more governed by tradition, rules for using specific colors were much more strict; choice dyes from rare sources were reserved for the garments of the kings or priests; some colors of clothing were believed to protect the wearer from pests and diseases or from supernatural forces.
Synthetic Dyes
In 1856, William Perkin, age 18, was challenged by his professor to synthesize the anti-malaria drug quinine… and accidentally made the first synthetic dye.
They called it mauveine.
Within 50 years, most of the dyes on the market were synthetics, mainly because they reliably produce the same color, but also because they make bold colors that are more colorfast and take to the fabric more quickly than natural dyes.
Dye VocabularyDyestuff– This is the plant material being used. Depending on the plant, the dye may be found in the roots, leaves, fruit, flowers, stems, and/or wood. Sometimes one plant can produce a whole range of colors. The typical ratio is one pound of plant material to one pound of fiber.
Mordant– A mordant is a chemical fixative which helps the dye molecules adhere to the fiber and stay there. That is, they help dyes be more fast. Many are metal salts and were discovered when dyers noticed that dyepots made of different materials yielded different colors. Different mordants work best with different dyestuffs and fibers. Some dyes need no mordant. Colorfastness– the extent to which a fiber retains a dye. red -- madder, cochineal (from an insect that feeds on prickly pear cacti), brazilwood, strawberries, cherries, red raspberries, lichens, roses, lavender, sumac fruit, dandelion roots, rose hips, chokecherries, beets, dried hibiscus orange -- carrots, butternut squash, giant coreopsis, barbary, lilac twigs, bloodroot gold/yellow -- weld, kamala, onion, goldenrod, osage orange, saffron, turmeric, safflower, alfalfa seeds, marigold flowers, heather, sumac bark, dandelion flowers, red clover, St. John's wort, paprika, dahlias green -- blue over yellow, sedges, artichokes, spinach, lilac flowers, snapdragons, coneflowers, pigweed, grass, barberry root, peach leaves, foxglove, lily-of-the-valley, red onion skins blue -- logwood, woad, indigo, alkanet, blueberries, cornflowers, hyacinths, saffron, dogwood fruit, red-cedar, red-maple bark, raspberries, black iris purple -- orchil lichens, cabbage, berries, logwood tan/brown/black – walnut, oak galls, oak bark, Colorado fir, broom bark, fennel, ivy twigs, wild plum root, dandelion roots, white birch bark, beets, coffee grounds Steps in the Natural Dyeing ProcessA. Wash fiber– Remove oil, dirt, sizing. Fibers must be wet for dyeing.
B. Gather plant– Approx. 1 lb of plant per lb of fiber C. Make dyebath– Chop the plant, then boil, simmer, or ferment to extract the dye D. Mordant– Fiber is soaked in mordant before dyeing or rinsed with a mordant after dyeing E. Dye– Simmer-dyeing works quickly, sun-dyeing requires the fiber to sit in the dye bath for days F. Rinse– To remove excess or unadhered dye molecules G. Dry– Usually away from sunlight H. Additives– Sometimes compounds are added to the dyebath or rinse water to adjust the color |
Experimentation and the Element of Surprise
No two dye baths will yield exactly the same results. There will always be an element of surprise: variations according to the season, the weather, the maturity of the plant, its position in the sun or shade, the quality of the water used for dyeing, even the type of pot used to dye the fabric in. It is for this reason that it's very important to keep careful notes about your process so that you can repeat the process with similar results in the future.
Lab Sketchbook : The importance of keeping records
Make This: Natural Dye Process
Traditional Dye Processes: batik, shibori, bandhani
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