Nearly everyone has heard that the Celts painted themselves blue with woad to appear more fierce in battle. The effect worked initially, even against the Romans, but the efficacy of such tactics wears off quickly. The blue paint eventually became symbolic in much the same way as North American Indian "warpaint" was.

What is woad? Woad is a hardy, perinnel plant (Isatis tinctoria) often considered a weed. Native to Northern Europe and the British Isles, it is a source of indigotin, a dark blue dye. One should take care when growing woad, as it is capable of completely taking over any area in which it is planted. So much so that it is possible to damage the existing eco-system if left to grow unchecked.

How do you get the dye out of the plant? Woad is what is called a "vat dye," which means a fermentation process is used to extract the dye in stages. To do this today you chop the leaves and stems of the plant, cover them with ammonia, and then beat the entire mixture until it's foamy (to force air into the liquid). Once the blue dye crystals separate from the vegetable matter and sink to the bottom, you pour off most of the the liquid and add water to the sediment. Then allow the blue particles to settle again. This process is repeated until you are left with just clear liquid and blue dye sediment. Now it's only a matter of evaporating the water away and you're left with a blue powder that can be store in jars or even compacted into balls, which is how it was sold in ancient markets. The ancient Celts couldn't run down to the local grocery store for a bottle of ammonia, however. In their time, the most readily available source of ammonia was urine and this is what they used. The leaves were fermented, dried out, fermented again and then rinsed in lime water.

Why did the Celts paint themselves blue? In the first century B.C., Herodian wrote, 'they mark their bodies with various figures of all kinds of animals and wear no clothes for fear of concealing these figures.' What he doesn't make clear is whether these marks were tattoos or merely painted images. However, it is clear that they decorated their skin using blue woad. These swirling patterns and intricate animal designs were believed to have magical powers that could protect them in battle. Aside from this esoteric protection, it has been discovered that woad is astringent and antiseptic, making it an excellent styptic, and the dye has psychotropic properties, which it can be imagined helped the warriors (both male and female) to get into the "mood" for battle. "So when ancient warriors painted themselves with woad before battle, it had not only a psychological effect, but also served to heal the wounds of battle."


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