The hidden history of woad blue: a path through technology and diffusion of “European indigo” in 18th-century technical literature

Woad, the famous “European indigo” plant, still hides some unknowns in its long history. This study wants to contribute to a better understanding of woad’s diffusion and use in Italy throughout the 18th and first half of the 19th century, by analysing the technical-agricultural literature of this period. The research allowed to collect some information on the “geography” of Italian woad, on its processing techniques and on its relation to “rival” Indian indigo, showing that Italy still had some relevant woad-producing centres at the time, and that woad was still acknowledged to have a significant dyeing function.