cardboard wing on baby ringmaster

I have never seen the folding flyers, they sound like a nice little plane for beating around.  I wonder if the blue fan fold foam would be a good substitute.  The paper covering apparently gets wet and weakens the wing.  The blue FFF is covered with plastic film on one side IIRC.  I really want to get away from the balsa now.  I am making a .15 size profile Weatherman and was pricing balsa.  I was lucky to find a piece of 3/8" x 4" and 1/2" x 3" for the fuslage in my stockpile.  The marked price was $3.95 from a "few" years ago.  Now it's $12+ 13% tax.  Then there is fiberglass and paint...  My flying buddy bought everything and was over $80.  Profiles used to be cheap simple and dirty, now a profile is more $, expensive, dirty and not really as simple as foam or something else may be. I reacall an Ohio Model Products (OMP) fuselage that is 1/2" foam with a balsa and plywood sandwich.  Nevertheless, if using the coroplast for a smaller plane I would search hard for the 2mm stuff, it is much lighter than the 4mm.  Oh, and I wonder how the Norvel folding flyers held up going fast with the undercambered wings.  I know some gliders and a Cox "Yard Bee" or whatever it was called had a tendency to tuck under in a high speed dive.