

Lots of airplanes are made of styrofoam (I think EPP might be the most common?). They typically have carbon fiber rods that run through the bits that need to be strong (like the wing).
The alternative is a traditional wood frame covered with heat shrink covering. Wood airplanes are stiffer and in my opinion they fly a lot better, but “foamy” airplanes have a lot to offer. The manufacturers can do some really neat designs which you can’t do with wood, so there are some really cool replicas of fighter jets, etc. They’re also cheaper to make, so they tend to be cheaper.








Rheingold hadn’t popped up in my brief research. Thanks for the naming tip!