Every material VViViD Vinyl offers is either a CAST or Polymeric material. Cast vinyl is stable when applied to a surface. It harbours no tension, whereas calendared vinyl harbours up to 25%. Calendared vinyl is made by processing a mass of vinyl through rollers and stretching it over hundreds of feet. Therefore when applied to a curved surface such as a car, calendared vinyl will shrink back causing curling, peeling and cracking. In contrast, VViViD's cast vinyl starts off as a liquid and is poured onto a sheet and baked. This means the cast was never stretched to begin with and will stay in place for the life of the vinyl.When cast vinyl is accidentally creased or stretched, you can heat it and it will return to its original form without creases or stretch marks. Polymeric offers the same advantage. It has been heated/treated and pre-stretched allowing for a cast-like application.