I'm always learning....I never heard of Fortrel until today..... So....what is Polyester? - We said they were two sisters (Polly and Esther) wearing kinda cheap, sweaty, clinging stretch fabric..quite colorful... And everybody in my neighborhood wore some polyester. So my mother sewed this quilt with polyester leftovers. My mother must have made this quilt back in the 60's.... Ugly but cute! Polyester is easy to care for (mostly machine washable) and keeps its shape and color well. The disadvantage of polyester is that it does not "breathe," which means it retains body heat and moisture and its not as comfortable as some of the natural fibers. Depending on the manufacturer, polyester fabrics have different names, many of which you will recognize - Dacron, Fortrel, Kodel and Trevira are among the many. Polyester may be offered in the form of knits, jerseys or cotton and silk-like fabrics.