... MD25-35% 4.Good Heat Sealing Heat Shrink Bag also known as: Super Shrink bags, square bags, retail shrink bags, pvc bags, ... bags, multipack bags, supershrink bags,Heat Shrink Wrap Bags,Domed PVC Shrink Bag,PVC Shrink Bag,PVC Heat Shrink Bag:Shape:Square,Cambered,Trapeziform, ... , then seal the open end. Bags are heat shrinkable to 40% and designed for quick-shrink micro-perf venting without ballooning ...