ANTHROPOLOGIE MOTH Women Black Open front Cocoon Sweater 40% viscose 30% polyamide 25% PTT 5% cashmere Tagged a size M/L Polytrimethylene terephthalate (PTT) form of polyester Pilling is not a fabric defect and may be present on pre-loved items. Pilling happens naturally when fiber in the material become loose and friction caused by movement on the fibers causes them to ball up. This is a normal, common and easily treatable. All fabrics will pill at least a little bit over their lifetime.