Following on from last week’s post about the mediaeval wool trade, we now look at some of the plant-based dyes that have been used since ancient times to colour wool – woad, madder and weld were often described as the ‘holy trinity’ for dyers.
The leaves of woad (Isatis tinctoria, a yellow-flowered member of the mustard family and also a medicinal plant) produce blue. It is a biennial that flowers and seeds in its second year with the leaves of plants grown in fertile soil apparently producing the bluest colour. The term ‘Pictish’ to describe the ancient inhabitants of northern Britain comes from the Latin term for ‘painted’, which is how the Romans described these people who used woad on their skin.
In mediaeval times there were important woad-growing regions in England, Germany and France, where Toulouse became prosperous from the woad trade. Woad was eventually replaced by the more colour-fast indigo and in the early 20th century, both were replaced by synthetic dyes. Read more about woad in Britain. Or go here to read more about woad in France.
The leaves of the indigo plant (Indigofera tinctoria) are soaked and fermented to produce the brilliant blue dye that has been popular for some 4,000 years. A legume plant (nitrogen-fixing), Indigofera tinctoria may be an annual, perennial or biennial, depending upon the climate. Dyeing with indigo is an intriguing process as cloth removed from the dye pot looks yellow, but rapidly turns blue when exposed to the air.
Madder (Rubia tinctorum) is a hardy perennial that spreads easily, so should only be grown with care and in confinement. The plant should be left for 3 years before roots are harvested. Apparently, adding lime to the soil in autumn or winter will produce a deeper red from the root. Cloth dyed with madder tended to fade so the European discovery of cochineal insects in Mexico, and the red dye they produce, was a revolution.
Weld (Reseda luteola, dyer’s weed) is another ancient dye, this one producing yellow from its leaves – brighter from fresh leaves and softer from dried leaves. The Romans used weld to dye the tunics of the Vestal Virgins. When over-dyed with woad, it produces ‘Lincoln Green’, which is supposed to have been used to dye the clothes worn by Robin Hood and his band in the 13th century. Used with madder it produces an orange. The biennial plant prefers to grow in limestone or chalk soil.
Just to note that ‘Lincoln Grayne’ originally referred to a high-quality red cloth, the word ‘scarlet’ then meaning not a colour but a cloth, while the ‘green’ was cloth of a lesser quality. Since at least the Elizabethan period, however, ‘Lincoln Green’ has meant a shade of green.
Other English towns also had specialty dyes, including “Coventry blue”, with the renowned permanence of the colour leading to the phrase “as true as Coventry blue” or “true blue”. Sadly, the recipe for Coventry Blue was apparently lost in the 17th century during the reign of the Puritans.