“WHAT KIND of copper rivets are these?”

According to Amy Leverton, denim editor for trend-forecasting company WGSN and author of “Denim Dudes, Street Style, Vintage, Workwear, Obsession” ($25, amazon.com), a book that celebrates the style of jean-world luminaries, that’s the kind of question ordinary consumers are beginning to ask when searching for that perfect pair. “I think there’s always been a passion for denim, but now it’s become much more of a mainstream thing,” she said. “People care about quality, and that’s really...