loomstate: Sukumo secrets: Nihon Menpu and Edo Ai

I thought I'd follow up the Nihon Menpu story with a more detailed look at one of the most fascinating aspect of their craft; their Edo Ai denim. the Sugar Cane jeans made with this fabric represent a mind-boggling mix of Japanese and American heritage.

The Edo period, from 1600 to 1868, is well known in Japanese history; it represented a time of great growth and change, including the establishment of a significant fabrics industry, and the production of indigo - Ai. Nihon Menpu's Edo Ai fabric is dyed using the traditional technique, of natural indigo produced using the Japanese sukumo method.

Sukumo is very different from the Indian method of extracting indigo. Producution is based primarily on Shikoku Island, just offshore from Okayama. Japanese natural indigo is extracted form the Polygonum tinctorium plant. Seeds are planted in late winter, transpolanted into fields in April, and harvested twicer in the summer. Sukumo is a composting process much like that used for making woad, but doesn't rely in milling the leaves; instead they are shredded, and separated from the stems, then spread into large beds, where they are composted; every few days the huge stack of leaves is sprayed with water and turned overto aid the fermentation or composting process. After around three months, the mass will have solidified and darkened. Traditionally it was pounded up and shaped into balls, named ai-dama. The resulting dye stuff is more concentrated than that of woad, and would be used to dye many popular indigo items, especially sashiko, the quilted working jackets.

For more information about natural indigo dyeing, I recommend Jenny Balfour Paul's wonderful book, Indigo.

Nihon Menpu's Edo Ai indigo is used in a traditional hank dyeing bath, controlled by Koji Nomiya. He hangs the large hanks of fabric onto large hooks, which are lowered into the bath; the forks rotate, twisting the hanks in different directions, so that the indigo is spread evenly onto the yarn; of course, being a manuall controlled process, the indigo is more variegated than a modern rope-dyeing system. In some of the photos here, you can see the yarns look green as they emerge from the bath, then turn blue as the indigo oxidises.

I'm not certain exactly what Sugar Cane jeans are currently made with Edo Ai indigo; I know my old pair, an approximately 1880s style jean rather like the old Nevada, were priced only slightly higher than their other jeans; a steal, considering the artistry and effort that goes into the dyeing and milling process.

I've also added some period photos of Nihon Menpu that further emphasise the company's amazing heritage. These shots date from 1917-1920 or so. I believe the looms shown are made by Toyoda, although there's a chance they were manufactured by the British company, Platt Brothers. More on both companies soon…