How old is woad?
Which of the following – ceramic pot, silk yarn, glass, woad or wheel – has the oldest archaeological record?
The ceramic pot, or fired pottery, is the oldest, at 6,500 BC. Surprisingly, woad comes second, long before the wheel, silk or glass; mankind was storing woad seeds in the Stone Age, possibly as early as 7,000 years ago. Fragments of blue-coloured linen or hemp found caught in an implement at a cave site in Adaouste in Southern France were dated to the Neolithic, while the inhabitants of other Neolithic sites were storing woad seeds. The other items on the list are all from the later Bronze Age, with the first wheel for transportation being invented around 3,200 BC in Egypt, the first silk discovered about 2,700 BC in China and glass only invented around 1,500 BC in Phoenicia.
If you have ever tried to extract woad pigment from woad leaves, you will be aware that it is a complex process that requires an alkaline environment, the correct temperature and the removal of oxygen. At first glance, it seems almost impossible that anybody would have come across this technique by chance.
Despite its complexity, most cultures around the world have independently discovered how to dye fibres blue using plants from different families. Indigo for example, comes from the bean family and is used in Asia and Central America; in Africa they use Lonchocarpus, another member of the bean family. In India they dye with a type of oleander and Sumatrans use a milkweed; japanese indigo is related to rhubarb, whilst the European and Chinese woad belong to the cabbage family.
How did people discover how to dye with woad?
Probably by direct observation and possibly by noticing that when the leaves were pressed by chance against their clothes, the clothes became a faint blue. Some of these leaves may have medicinal properties and may have been used crushed in poultices under bandages. Another possibility is that Neolithic man or his animals ate woad leaves in times of famine and saliva mixed with chewed woad coming into contact with clothing resulted in the fibres becoming faintly blue.
Over the centuries the process developed into purposefully pressing crushed woad leaves against fibres. The leaves have to be fresh to be used in direct dyeing, therefore plants that produced blue would most likely have been cultivated by an increasing number of people. This happened to woad which slowly spread into Europe from its native origin in the Mediterranean (Turkey and the Middle East).
Dyeing textiles blue
Linen and hemp, the main fibers available in Neolithic times, are not as easy to dye as wool. An added complication is that direct dyeing is a slow method that would have allowed only a limited amount of fibre to be dyed. Colour, therefore, would have been used sparingly and mainly on the border of fabrics. Indeed blue borders were found in some of the cloths used to wrap mummies in ancient Egypt at about 2,500 BC, though coloured borders were apparently not in common use until 300 BC.
All the chemicals necessary for dyeing were readily available. Ammonia, in the form of stale urine, was often used for cleaning because soap was not invented until the first century AD. Stale urine is alkaline, and the bacteria living in it remove oxygen from the liquid. A bunch of woad leaves gathered near houses for direct dyeing, would sooner or later fall into a urine barrel in the summer and the next fabric to be cleaned in the barrel would come out pale blue. Anybody witnessing this would have been very impressed.
With time, wool became available and a better process for dyeing with woad was developed, making it easier to dye enough fibre to weave whole garments. A young girl wearing a blue dress, very likely dyed with woad, was found in an Iron Age grave (circa 1st century AD) in Denmark.
Woad & pottery
Woad was not used only for dyeing; the abundant black woad seeds are shaped like tongues with a ridge in the middle and with a tiny tail, leaving a pretty impression on clay. These seeds were used to decorate pottery in Iron Age settlements in Germany.
Urine vats, also called sig vats, are still used today for historic re-enactment or as an easy and cheap way of dyeing with woad. Most dyers today, however, do not have the patience to wait two weeks for a urine vat to work, neither are they prepared to put up with the smell of stale urine. If you want to dye with woad, the simplest and quickest way is to prepare a chemical vat, using soda ash to make the vat alkaline and spectralite to remove the oxygen.
Whichever method you chose, the ancient or the modern woad vat, you will find it very exciting to get the same blues as Stone Age man. And if you want to go a step further, you can easily grow woad and then extract your very own precious blue pigment.