The Woad plant (Isatis tinctoria) has been famous as a source of blue pigment for several thousand years.
Its main use is as a dye for wool and other fabrics. The pigment is extracted from the dark blue-green spinach-like leaves of the woad plant that is a close relative of spinach and other brassicas.
For more information on woad, including several methods of dyeing with woad, see All About Woad at www.woad.org.uk.
