Here's a page worth reading.
A quote concerning shuttle looms used in Japan:
"In response, Hidehiko Yamane's company, Evis (changed to Evisu, for obvious legal reasons), developed the first reproduction vintage Levi's in 1987. By the nineties Japanese companies such as Sugar Cane, Iron Heart, and Denime were crafting limited-edition near-museum-quality replicas of classics like the 1947 Levi 501 and 1942 Lee 101B. All three labels used the ancient indigo dyes that caught on with collectors such as Ayre. They also wove the cotton into denim on a type of mechanical loom that had been sitting in factory basements in Okayama, the country's weaving capital, since the seventies. These machines produced narrow fabric (30 inches wide as opposed to the standard 70), yielding a cloth with a denser thread count, a softer feel, and a finished edge. Called selvage denim, it is now among the most hotly pursued premium jean material in the world."