I built this plane using a combination of foam board (paper not removed) balsa and some ply .61 for power.
The wing ribs were foam board, the fuse sides bottom and top foam board with some ply and balsa doublers were I had to have the strength and as attachment points. Also the tail feathers were foam board with spruce spars.
Covered in fabric and doped.
Flew fantastic till some one turned their transmitter on that was on the same frequency as mine.
Just takes some real thought as to structure.