For Frouke Bruinsma of G-Star Raw, sustainability is a marathon, not a sprint. Case in point: When she joined the denim brand as a legal counsel 15 years ago, it didn’t even have a corporate responsibility department.

Bruinsma helped G-Star take its first steps toward a more mission-based approach to doing business, establishing its CSR team in 2006 and then the GSRD Foundation in 2007, which supports education and entrepreneurship projects in G-Star production countries.

“Over the years, we built the corporate responsibility department around four pillars: responsible supply chain, sustainable product, sustainable operations and community involvement,” she said.

In her role as sustainability director, Bruinsma works to “close the loop” on denim through circular techniques. Her crowning achievement so far? Paving the way for G-Star’s most environmentally friendly jeans to date by developing, in tandem with a group of experts, the first denim fabric to be certified at the Gold level by the Cradle to Cradle Products Innovation Institute.

The technology is open source through the institute’s Fashion Positive Materials Library, chiefly because Bruinsma believes sustainability is about teamwork, too.

“It was important for us to encourage others to join us towards cleaner and more ethical denim production,” she said. “The denim industry is bringing about many great collaborations in the supply chain; it’s great to be part of this process.”

Denim has the potential to become the cleanest part of the fashion industry, Bruinsma said, but she knows that won’t happen overnight. In the short term, she’ll settle for a way to use a higher percentage of post-consumer recycled cotton in jeans, “to replace all other types of cotton we use in denim production nowadays.”