Remote control airplanes are a fun and (usually) inexpensive way to pass the time. With some foam material out there being easily breakable, it sometimes may be tough to find the right kind. The trick is to finding the plane that has a combination of portability, price, and toughness. With a little bit of searching, it can be done. While few planes will survive the learning curve of a beginning RC flyer, there are a few out there that will. The foam that makes these up are tough, cheap, and light. That combination is what makes the best foam in the RC market.
Expanded Polypropylene, also known as EPP, is an engineered plastic foam material. This foam is extremely durable and lightweight, because it is made out of little bubbles of CO2 and polypropylene resin. This type of RC foam is inexpensive to manufacture, making the price of the airplane usually lower also. This foam will withstand even the hardest crashes.
With the increase of DIY airplanes, many RC fanatics are complaining that EPP foam is not mold-able. Elapor foam is made primarily out of Styrofoam; so, while it isn't the most durable, it is able to twist and turn into new things unlike its EPP sister. If you are looking for a somewhat tough, flexible foam, than Elapor may be the choice for you.
Expanded Polyolefin is a durable, flexible, and adhesive-friendly foam made primarily for RC gliders. It is both durable and lightweight, but it is quite expensive as it isn't the standard foam used by companies. Expanded Polyolefin (EPO) is ready, however, to take any kind of glue, tape or finish needed for the touch-ups on your airplane. The EPO foam is a great all-around performer for your airplane.