Hi Irving2008

VC10 is built with 3 type of foam Depron which comes in various widths 3 and 6mm being the most popular. Its mainly used for underfloor heating insulation. XPS is the pink/orange looking foam and is similar to blue foam used a lot in RC flying. This stuff is mainly used for wall insulation and I get mine from B&Q. The wings are the usual polystyrene foam which acts as a core and strengthened with a spar ( carbon rod or spruce) and a balsa leading edge. its then covered in brown parcel paper which is glued on with thinned PVA, a bit like wall papering. Amazingly strong once dry.

Keith