Prime Bubble-X® is a sheet / air-bubble co-extruded PPTW (Polypropylene Twinwall-Fluted) board. A new patented technology, it is a co-extruded board made of three layers: a central thermoformed core, and two flat, compact “external skins” with “matte” finishes. These external layers are smooth and corona-treated to provide outstanding printing performance.