GreenStar and Oracal are two different brands of vinyl. GreenStar vinyl is all calendared which means that is extruded, or stretched, during the manufacturing process. Oracal makes calendered vinyl as well, but they also make cast vinyl which is not stretched during the manufacturing process. Cast vinyl is generally higher in quality than calendared. For more information on the differences between GreenStar and Oracal, as well as Cast and Calendared vinyl, please click the link below to watch a video explaining the differences in more detail.