Traditional Japanese needlework has exploded in popularity, but a book from a third-generation artisan aims to bring more context to the craft's newfound popularity. | QUADRILLE PUBLISHING In recent years, sashiko , a Japanese needlework tradition, has gained a new cultural cache among international fashionistas and craft hobbyists. Most notably, the Iwate Prefecture-based Sashiko Gals project has helped rural artisans insert their needlework into New Balance sneakers, North Face jackets, New Era caps and more. Hardly a day goes by without my social media feeds featuring overseas creators claiming to be sashiko experts. However, in “ Sashiko: The Untold Story ,” a new book by third-generation sashiko artisan Atsushi Futatsuya, the Gifu Prefecture native lobbies for a more conscientious treatment of the craft and its long history as a tool of Japan’s commonfolk.…