London’s venerable Savile Row was transformed into a country fairground on Monday as sheep frolicked in the streets to herald the start of Wool Week. Amidst the fluffy conflagration stood (or perhaps more accurately, sat) a pair of curved-back slipper chairs, clad in a new textile derived from wool and recycled Starbucks coffee sacks. Dubbed “WoJo,” a portmanteau of “wool” and “jute,” the material was first conceptualized by The Formary, a New Zealand-based design company, then manufactured for the Frappucino purveyor in collaboration with U.K. weaver Camira and Wools of New Zealand.

Turning coffee sacks into chairs—a process that spanned 18 months—required some mental calisthenics: One of the biggest challenges was keeping the jute fibers from shedding. The solution came to Bernadette Casey, director of The Formary, after visiting a felt exhibition in New York. “It occurred to me that the perfect way to reduce the jute shedding was to blend it with wool,” she says. The more I thought about it I was convinced we were onto something. And so we began experimenting with wool and recycled jute in a number of different applications.”

Another hurdle was finding the right partners for the job ahead. The Formary picked Wools of New Zealand for its sustainably farmed Laneve wool, and Dell’Orco & Villani, which manufactures textile-recycling equipment, for their technical know-how with recovered fibers. Working with Camira made perfect sense, as well, since the company was more than familiar with operating with baste-fiber upholstery.