Indigo is derived from Indigofera plants native to India, especially Indigofera tinctoria, while woad is extracted from the leaves of Isatis tinctoria plants, native to central Asia and widely cultivated across Europe. Chemically identical to one another, these two dyes yield a deep blue colour often use by illuminators to enhance and complement the more precious mineral blues - ultramarine and azurite.

Indigo and woad cannot be distinguished with the analytical methods used for this project; the two terms are therefore used interchangeably throughout this website.

Related content: Folios