Natural Dye with Woad

## Natural Dye with Woad

Woad (*Isatis tinctoria*) is the ancient blue — the colour of the Picts, the war-paint of Boudicca's warriors, the sacred pigment of the Celtic world. Long before indigo arrived from the East, woad was the only source of true blue dye in Europe, and its cultivation and use stretches back thousands of years across Britain and northern France.

Growing woad is straightforward — it is a biennial plant in the brassica family, thriving in well-drained soil and full sun. The first-year leaves are harvested in midsummer, when the indigo precursor compound (indican) is at its highest concentration. The extraction process involves crushing the leaves, fermenting the resulting paste, and then carefully managing the chemistry to precipitate the insoluble blue pigment.

In this workshop, you will learn the complete woad dyeing process: from harvesting and preparing the leaf, through the fermentation vat, to the magical moment when cloth pulled from the yellow-green dye bath turns blue on contact with the air. This oxidation — the indigo molecule locking into the fibre as it meets oxygen — is one of the most dramatic transformations in all of natural dyeing.

We will work with cotton and wool samples, exploring how different fibres take the dye differently, and how mordanting (pre-treating the fibre) affects the final shade. You will learn to build and maintain a woad vat, understand the pH chemistry involved, and produce your own pieces of woad-dyed cloth — carrying the ancient blue forward into the modern world.

Safety and environmental considerations are covered throughout. Woad is non-toxic and the spent vat material makes excellent compost, making this one of the most sustainable dyeing processes available.