Stretch fabric is nearly impossible to recycle—but this startup just made it simple

Your old yoga pants are a recycling nightmare. A startup called Return to Vendor found a new solution—by redesigning the molecules in nylon. Stretch fabrics are notoriously hard to process. When your old leggings wear out, they will probably end up in a landfill—even if you try to drop them off for recycling. But a Manhattan startup has developed a new material that could finally make this corner of the apparel industry circular.