EPP: The Miracle Foam
All JW and Sonic gliders are made from EPP foam. EPP foam is the most resilient foam available for foam airplanes. EPP can take a lot of abuse and yet return to its original shape. Pat Bowman discovered EPP for R/C planes in the 1990's and since that time there have been countless EPP planes brought to market worldwide. Since slope gliders are subjected to repeated hard landings and mid-air collisions, EPP is the natural choice for any model that needs to endure the rigors of slope abuse.
EPP planes from jwglider.com are easy to build. The hard work has been done for you: leading edges are precision CNC shaped; spar channels are pre-cut; fin slots are pre-cut; wing slots are precision CNC cut; fuselage profiles are precision CNC cut. All that remains is a few minutes of sanding with a sanding block and then you are ready for radio install!