Welcome to the final episode of the Diesel: Behind the Denim docu-series, dedicated to demystifying the denim production process and highlighting Diesel’s commitment to delivering more style with a smaller environmental footprint.

Episode 5, Waste to Treasure, follows host Lea Ogunlami to textile expert Tejidos Royo in Valencia, Spain, where she explores the concept of circularity—a term increasingly used in the fashion industry. Surrounded by towering piles of denim scraps in a warehouse, Lea learns that circularity means finding innovative solutions to eliminate waste and continuously reuse materials.

Fabio, Diesel’s Supply Chain Sustainability Manager, explains that Diesel uses around four million meters of denim material annually to produce its collections. Even with the most efficient cutting and construction techniques, approximately 15% of material ends up as excess—scraps that fall to the atelier floor during garment creation. Do the math. The good news? Diesel and Tejidos Royo have developed an industrial process through which textile waste can be shredded and broken down, then respun into yarn and combined with conventionally recycled cotton to create a new type of fiber.

The Diesel Rehab Denim program is a prime example of cutting-edge circularity. Tejidos Royo representative Alberto Guzzetti walks Lea through the step-by-step process behind this collection. Each piece in the Diesel Rehab Denim line is made from 100% recycled cotton and elastane derived from pre-consumer waste, blended with TENCEL™ Lyocell using REFIBRA™ technology. The final stage involves Dry Indigo®, an innovative dyeing technique patented by Tejidos Royo, which applies dye to the fabric through air spraying—without using any water. This drastically reduces the amount of chemicals and energy involved in the dyeing process.

As Lea sums it up: “All I’m hearing is that Diesel Rehab Denim is sensational.”

Diesel: Behind the Denim comes full circle, ending where it all began—with Lea and Creative Director Glenn Martens meeting at Diesel’s Milan headquarters for a debrief. After gaining insights into Diesel’s sustainability journey and responsible production practices, Lea reflects that denim is “a kind of global uniform, with major impact.”

Glenn agrees. If you want to approach sustainability on a scale as massive as Diesel’s denim production, “You better go big.”