There was an interesting piece recently on the local evening news about Prince William visiting a laboratory in Norwich called Colorifix. They are doing amazing work inventing ways to create colours for dyeing textiles that are not based on petro-chemicals (as most dyes are). They extrapolate the dna of a natural product (without actually using the product) and insert it into a microbe to create the desired colour. It will be so interesting to see if they can succeed and whether they will be able to roll it out commercially. It could change everything. It reminded me that I wrote a couple of months ago about colour, focussing on the development of commercial dyes, and that I had promised myself that I would come back to the subject of natural dyes at another time. Somehow, now seemed like a good time.
Until the invention of synthetic dyes in the 1850s, all textiles were dyed using natural dyes. Natural dyes are derived from plants, inverterbrates or minerals. The majority are vegetable dyes from plant sources (roots, berries, leaves, bark and fungi), but dyes can also be obtained from insects (cochineal), and molluscs (Tyrian purple). The essential process has not changed very much over time. Usually the dye material is put in a pot of water and heated to extract the dye compounds into solution with the water. The textiles to be dyed are then added to the pot and held at heat until the desired colour is achieved. Textiles can be dyed before the spinning/weaving process (“dyed in the wool”), after spinning (“yarn dyed”) or after weaving (“piece dyed”).
In order to fix the dye to the textiles and stop them washing out, it was often necessary to use mordants. The word mordant derives from the Latin mordere which means “to bite”. Mordants are metal salts that will form a stable molecular coordination complex with both natural dyes and natural fibres. The most common mordants, still used today, are alum (potassium aluminium sulfate) and iron (ferrous sulfate), but there were others, such as salts of metals of chrome, copper, tin or lead, which are rarely used now due to modern research evidence of their extreme toxicity either to human or ecological health, or both. There are also some non-metal salts that can be used to fix dyes to natural fibres, including tannin from oak galls , and ammonia from stale urine. Some dyes and the mordants smell terrible and large scale dyeworks were often located in their own districts, away from residential areas. Very poor people would sell their urine to dyers and tanners – the phrase “he hasn’t got a pot to piss in” refers to this practice and means someone so poor they could not even use this way of making money.
As anyone who has ever done art at school will know, you need three colours, red, blue and yellow, from which all others will flow. Archeologists have discovered that as early as Neolithic times, people were dyeing textiles with madder (red) as did the Ancient Egyptians, who also used saffron (yellow) and indigo (blue). In Europe, woad was the source of most blue dye until the markets with the East were opened up and indigo took over and destroyed the woad industry. The Romans regulated dyeing practices, and had guilds and laws about what colours people could wear. Tyrenian purple, designated Imperial purple, requires huge amounts of the mollusc Murex to make. The Emperor Nero ruled that it was punishable by death for anyone else to wear it. In the Middle Ages textile producers created black dyes from a combination of ferrous acetate and oak gall and this quickly became the colour of the wealthy and by the 18th century the colour of lawyers and other professionals. The discovery of the New World also resulted in the bringing back of crimson from the kermes insect.
There are many sources of the different colours. Blue comes from dyers woad (the leaves, not the yellow flowers) or indigo. Weld produces such a joyful yellow it is known as ‘gaude’ (joy) in French. Green can be obtained from wild carrot and brown from walnuts, dock or onion skins. Elderberries create a variety of colours including purple. Reddish colours can be got from rhubarb or beetroot. But my friend Jen Monihan of Fibreworkshop, says that the old ones are the best – madder, woad, Japanese indigo, weld. And she should know – she dyes the most wonderful colours onto Norfolk Horn wool. We stock some here in the shop and I love the muted colours.
I have been wanting to take up dying with natural dyes for years. I have even gone so far as to create my own dye garden! But somehow I never seem to have the time. One day perhaps. In the meantime, I will be watching the progress of the people at Colorifix with interest.