What is Polycaprolactone? Perhaps you have heard of it from various American companies such as InstaMorph, Shapelock, Missing link, Friendly plastic, Hand Moldable Plastic, Mold-Your-Own Grips Polymorph, or Plastimake. It is a non-toxic, biodegradable and lightweight polyester thermoplastic that becomes moldable at a relatively low temperature (60C / 140F) and solidifies at room temperature. These properties make it ideal for use for all projects and skill levels.