colour chemists
 |
 |
 |
textile, recruitment, industry, technologists, dyehouse, managers, shift, dyers, spinning, knitting, weaving, factory, printing, colour, chemists, sales, clothing, industry, dyestuff, sales, chemical, auxiliaries, colour chemists
Scientists and historians are almost certain that dyeing was practiced throughout the historic world, but it is difficult to obtain proof on this for two reasons. First, not all cultures left written records of their practices. Second, because of the wide variance of environmental conditions and degree of geological disturbance, it is not easy to find well-preserved evidence of dyed textiles in many archaeological sites. A Chinese text from 3,000 BCE lists dye recipes to obtain red, black and yellow on silks. Ancient Indian texts describe several different yellow dyestuffs, how to obtain reds from the wood and bark of certain trees, and also notes the use of indigo to create blues on cotton. In Central and South America they dyed bast fibers (plant fibers) in shades of red and purple with the bodies of the cochineal insects (Dactylopius coccus).
A Greek artifact known as the Stockholm Papyrus details dyestuffs and techniques in almost a recipe fashion as it was practiced Egypt in the third and fourth centuries CE. The great detail in which the preparation of the fibers and the dyeing materials and the dyeing process itself are recorded has led scholars to believe that it had to have been practiced for thousands of years previously in order to raise the process to such a science and art. It discusses mordanting the fibers using alum, copper and iron oxides to darken or "sadden" the red, blue, green and purple dyes, as well as the occasional use of tin and zinc. It describes over ten different recipes for using alkanet (Anchusa tinctoria) root as a dye employing camel and sheep urine, lentils, vinegar, wild cucumber and barley malt among others as aids to producing color. It also gave recipes on obtaining purple hues by overdyeing the alkanet with woad (Isatis tinctoria), madder (Rubia tinctorum), kermes (made from the dried bodies of the female shield louse or scale insect (Kermes ilicis)) and the heliotrope plant (Heliotropium arborescens). Excavated coptic textiles dating from the fourth to the sixth century CE show use of weld (Reseda luteola) to produce yellow, madder and woad for dark purple, and blue from indigo (Indigofera tinctoria). Scientists have been able to date a red obtained from Egyptian madder root from the fourteenth century BCE.
In the Mediterranean before the advent of Christianity, a whole dyeing industry arose around Tyrian purple. Tyrian purple is produced from the mucous gland adjacent to the respiratory cavity within some species of Purpura and Murex species of shellfish. The shells were crushed to extract this fluid, which only turns purple once it has been applied to the fiber and exposed to light and oxidation with the air. The Phoenicians, skillful shipbuilders and sailors that they were, scoured the coastlines for sight of these whelk shells, and established a dyeworks and trading station wherever they found a plentiful population of these shellfish. Coastal Indians of Mexico were also using shellfish, but their delicate method involved blowing and tickling the shellfish to get them to spit out the dye precursor directly onto the cotton fibers. Even Ireland can produce archaeological evidence of dyeing with the native dog-whelk shells in the seventh century CE. Both Discorides, the Greek physician and Pliny the Elder, the Roman naturalist, mention in their first century works the preparation and dyeing of wool with various shellfish to produce colors of red, blue, purple and violet after first being mordanted with soapwort (Saponaria officinalis), oxgall or alum.