TI-CRON polyester sutures are nonabsorbable, sterile, surgical composed of polyethylene terephthalate. They are prepared from fibers of high molecular weight, long-chain, linear polyesters having recurrent aromatic rings as an integral component. The braided sutures are available uncoated or coated uniformly with silicone to increase surface lubricity, thereby enhancing handling characteristics, ease of passage through tissue, and knot run-down properties.