They took fibers leftover from making other yarns- the soft too-light fluff, the bits that otherwise would have been lost to the waste stream - and made this handy, durable, and surprisingly soft high quality yarn. This 85% recycled cotton/15% recycled polyester blend is called "clean cotton" because its a yarn you can feel good about using._PRODUCT FEATURESFiber Content: 85% recycled cotton, 15% recycled polyesterBrand: Universal YarnYarn Thickness: Worsted (4)Skein / Hank / Ball Weight: 1.9 oz / 55 gYardage: 96 yds / 88 mRecommended Knitting Needle: US Size 8 (5 mm)Recommended Crochet Hook: US Size I/9 (5.5 mm)