WOAD-SENG A Conference Report by Michael Bischof

Erfurt, the Thuringian center of woad trade during the Middle Ages and today the capital of Thuringia, was the scenic locale of an international congress on woad in early June. Participants and visitors came from western Europe and Japan. In Japan a living craft based on Ai (Polygonum tinctorium) continues. In France, renewed interest in woad, today for use in cosmetics and medicine, has sprung up near the historical woad centers of Toulouse-Albi-Carcassonne. In addition, England's woad historians were present, as were enthusiasts from Austria, Switzerland, and Germany.

I attended the conference on woad with high expectations, and I am happy to report those expectations were not frustrated. The lectures focused on the following broad topics:

Woad in the history of commerce
Woad as a natural dye -- ingredients, evaluation of possible applications
Woad as a source of modern medicine and cosmetics
The Japanese Awa-Ai craft in past and present

Lectures on woad in the history of commerce did not touch upon Oriental textiles. Readers interested in this topic may contact the conference organizers:
Dr. H. Benneckenstein and H. Müllerott
Gartenbaumuseum der Erfurter Gartenbau und Ausstellungs GmbH
P. O. Box 460
0-5010 Erfurt, Germany

Enthusiasts of natural dyes and readers of books on the art of dyeing will already know about the process of squeezing the fresh woad leaves, forming balls of it, and storing those balls for weeks under humid conditions until they are dried and may be used as a dye years later. In German, this is called Gärung of woad, a process which is entirely anaerobic at the main stages. Often this is mistaken for the reduction of indigo to its colorless or yellow leuco form when making a vat, which is a different process. Prof. Dr. Ortwin Meyer from the University of Bayreuth discussed the microbiology of Gärung of woad and gave evidence that this process is, in fact, an aerobic microbial transformation. Indican and Isatin B, precursors of indigo in the leaves, are changed to indigo by this transformation. The yield is low with 0.4% indigo in the dried leaves and 1% in dry woad balls.

Prof. G. W. Krausse and Andrea Kliem presented a paper about the present status of woad as a cultivar and the prospects of improving it. From its variability it seems to be a wild plant, not the residue of a formerly cultivated form.

If a lecture program can be considered a kind of sports competition, I would guess that England beat Germany 3-0. Gisela Bugge introduced a quick test on indigo in woad, which is not quick in the strict sense; in addition, it is not clear whether disturbances will occur with flavonol compounds of woad (the reason that it is possible to make yellow colors from woad on mordanted wool). David J. Hill from England showed a quick test on Isatin B which is transformed to indirubin quantitatively within minutes; scientifically, this test is much more simple and, therefore, more sophisticated -- simple truth appears elegant. I dare predict that both hobby dyers and professional dyers will work with the Isatin B compound of woad, if they work with woad at all. Indican woad cannot compete with Polygonum and Indigofera.

In Japan an old craft has successfully been kept alive. Today about 40,000 kg of dry Polygonum leaves are sold each year to dyers who use it in the creation of cloth. It was a delight to see Awa-Ai indigo-dyed clothes on the Japanese participants. This demonstration served to underscore how much is lost in the creation of many carpets made today in Turkey and Iran in which synthetic indigo colors dominate, giving no hint of the potential beauty of the same item were real indigo used.

A similar truth was revealed in the work of the blue printer, Sigrid Weiss, who learned this craft as a hobby and then turned professional. Her husband is responsible for indigo dye. I saw here the best synthetic indigo dye on cotton I have ever seen. Blue printed home textiles have a long tradition in Thuringia.

In conjunction with the congress was an exhibition of historic textiles from Japan, material from France, and, to my great astonishment, a piece of plain indigo extracted from woad. Anyone who has tried this is aware of the immense effort and time required before the desired result is finally attained. For many years I have held the opinion that making wine and making natural dyes are comparable efforts, demanding the same skills. So it was a rewarding confirmation of my opinion to meet a young German wine producer, Mr. Laftenberger, from Neckarwestheim, who has succeeded in both.

He displayed an Oriental carpet of his own "production"; in fact, it is his hobby. With a few exceptions, his dyes are far better than anything that is today called "natural dye" in Turkey or Iran, rivaling excellent village rugs from the last century. Because his taste in combining and juxtaposing colors is non-oriental, however, his rugs could not be mistaken for Oriental carpets.

A highlight of the congress was a fascinating excursion to Neudietendorf to visit an historic, working woad mill. Woad balls were formed and a woad vat was set up for a demonstration. Today Mr. Feige produces wood protection dyes based on woad and a kind of woad ball designed to be used by dyers.

Truthfully, and not for the sake of politeness, the Erfurt hosts must be mentioned. The simultranslation on a difficult subject was perfect. Further, to be hosted in the rooms of the Augustinerkloster, where Martin Luther once lived and worked, offers an experience that money cannot buy. A familiar atmosphere prevailed, and I did not detect a single soul who was not overwhelmed by the event. On the other hand, any new interest in woad will certainly not endanger the 4,000 tons of synthetic indigo that BASF Ludwigshafen, the principal producer, sells per year. Those who have worked with woad successfully know that coloristically it is more charming for open colors than synthetic indigo. Dark colors are possible, too, but make no sense. In Turkey there are forms that mainly release indirubin, which is even more interesting.

At present it seems that blue, violet, brown, green, and yellow can be made from woad. Research will show that woad appears much more often in Oriental textiles of the last century than is commonly believed today. But whether woad can be used professionally today remains an open question because of the expense. Dyers can afford to make only that quality which they can sell. And with prices like 40 DM for 1 kilogram woad balls yielding 10 grams of plain indigo, as was suggested by Mr. Feige, even hobby dyers will prefer natural indigo at 80 DM per kilogram, yielding about 200 gram of plain indigo.

Concerning the other applications of woad, this congress was like opening a door to a dark but promising room, full of secrets waiting to be discovered; only tiny pieces are visible at a time. Therefore, Dr. Kohlhaupt from BASF compared woad with ginseng, postulating that both are more psychosomatic than real. I agree but insist on the full content of that comparison: in ginseng, there are at least two independent bioactive principles that can be proven scientifically, and there is room to discover more. If woad ends up like ginseng, for textile people it will have a bright future.