Woad back in vogue

2019-03-07 01:14:03

By Andy Coghlan QUEEN BOUDICCA and her Iceni warriors smeared it on their faces to terrify the Roman invaders. Mel Gibson revived the fashion in the movie Braveheart. Now catwalk queens could soon be wearing it in their designer garments. What is it? Dye made from woad (Isatis tinctoria), a member of the cabbage family. David Cooke’s team at the Long Ashton Research Station near Bristol have been working on a project to make dye extraction from woad a viable industrial process (New Scientist, 20/27 December 1997, p 19). It is now bearing fruit, and the researchers are confident that their natural indigo dye is more environmentally friendly than the synthetic version, whose synthesis involves the toxic chemicals aniline, formaldehyde and hydrogen cyanide. Although the woad-based indigo is more expensive, Cooke believes fashion designers won’t mind paying extra to underscore their green credentials. “The idea of a dye that’s indigenous to the Anglo-Saxon culture is hopefully something people can pick up on,” he adds. Woad leaves contain indican and isatan B, precursors which form indigo on contact with air. “The leaf material is extracted with water, the acidity is adjusted and the resulting liquid exposed to air,