Everyone knows about the corrugated floor. I need to smooth it out by
placing cut strips of SOMETHING in the valleys. The ideal material will be
lightweight, 5/16ths thick and cuttable with a box cutter and metal
straightedge.
Any suggestions?

I do have 3/8ths Rubatex closed cell foam for the floor from
http://www.rbxcorp.com/ and that is a great material!

-- Rachel