Certain countries have become synonymous with the textiles they produce. There’s Australian wool and Chinese silk. When it comes to denim, Japan reigns supreme. Even though blue jeans were invented in the United States in the late 1800s, the raw material used to make them has been elevated to something more in Japan. The new documentary Weaving Shibusa tells the story of how that tradition came to be.

Directed by Devin Leisher, who previously directed a doc about raw denim in the U.S., the film tells the story of the so-called “Osaka 5,” the five companies that helped revive Japanese denim by faithfully reproducing styles from different periods throughout history in a manner that is as much an art form as it is a manufacturing process.

Much like in Japanese knife-making, the old guard lacks an upswell of young people willing to put in the work required to learn the craft and keep the tradition alive. As one person notes in the film, “There are almost no young people who can fix a shuttle machine” used to weave the denim, so it is an incredible opportunity to hear from these founding fathers before the craft peters out.

Weaving Shibusa will premiere at the Castro Theatre in San Francisco on August 6.