Rvfm polypropylene corrugated board rvfm ep700ppfldb polypropylene corrugated board is often referred to by the trade name cortex it is a lightweight tough material which is easy to cut using a craft knife the material can be joined using a wide variety of techniques from gluing and stitching through to fastening with click rivets or corri joiners rvfm corrugated plastic 605 x 605 x 4mm pack of 10