Last Saturday at the Weaving and Fiber Arts Center, I taught a class on "Getting the Blues: Natural Dyeing with Indigo and Woad." The short story is that, among some 275 plants that have usable amounts of indigo in their leaves, woad and indigo are the most popular worldwide, indigo itself (indigofera tinctoria) being the most popular natural blue dye of all time. Both have been used for thousands of years (woad, for example, was used in the British Isles by the Picts to paint themselves blue during warfare). The textile industry in southern France, centered in Toulouse, was devoted to woad -- until the 16th century, when indigo was introduced from Asia and, literally, blew it out of the water! (OK, so I can't resist a bad pun.)
Indigo has the most concentrated levels of the blue pigment, which is why it's preeminent among its competitors. So I thought we'd have a class to demonstrate why. The photos below give you some of the results. (There are several qualifiers here: We were using chemical vats, not the fermentation vats of tradition, and students were using a variety of fibers. None were mordanted; all were soaked in water, some for days.)
Above, Janet Leone's wool yarn dyed in indigo (left) and woad (right).
Photo: This was some wool roving that Judith Trolley brought along. She hadn't had a chance to soak it in water -- but the results were wonderful, none the less. She dyed this with both woad and indigo, to achieve a varied effect. Next comes the spinning, which I hope she'll share with us!
Photo: Mohair boucle brought by Eleanor Hartquist -- the skein on the left was dyed with woad, and the skein on the right was dyed with indigo.
Conclusion, from our brief and less-than-scientific experiment: All else being equal, indigo does, truly, provide deeper blues. Woad yields a lighter color, with just a bit more aqua to it, but equally beautiful, if not more so, to my eye. Ah, yes, the colors of southern France!
Thanks to all for a wonderful mess, er, class. And thanks especially to the folks who helped clean up. The dyeing kitchen looked pristine when they finished!