Picts probably used woad, but not for that!

Rumour has it that the Picts painted themselves blue with pigment from the dye plant woad but it is unlikely they did so for a number of reasons. Woad pigment only goes bright blue under certain conditions such as in a dye bath for fabric or when cooked in very small batches with gypsum. Put directly on skin it appears as a very unimpressive greyish streak – and don’t even think about tattooing with it because it is very caustic and will burn! However,. the Picts may have used woad in their manuscript art. The Book of Kells contains a lot of Pictish style animals, and many of them are coloured in with woad.