A few years ago I attempted to make a small layout out of card board (corrugated paper). It was going to be a simple figure 8 under and over. It was going to be built totally out of card board. I gave up on it because I couldn't find large enough sheets of card board. Also cardboard from different manufacturers is different thicknesses. Places in the cardboard where folds occurred also caused irregularities when I started to assemble the layout. It was just a test to see if it could be done. I haven't exactly given up on the idea, but not a high priority at the moment.
Go to a store that sells moving supplies...like u-haul...buy a king size mattress box...nice and new corrugated cardboard...clean, flat and uniform thickness...
Howard..
Thank you for the suggestion. I hadn't thought of that. To explain a little bit more. I was trying to do this with house hold items or things that could be gotten cheap or free. Corrugated paper: almost all companies throw this stuff away but hopefully recycle it (no I'm not a tree huger). Therefore an almost endless supply and probably for free. The idea being was to show beginners how to build a layout with in expensive items, maybe it would encourage them to build a layout and thus we get more people into the hobby.