Any hobby shop carries plywood for airplanes. Baltic Birch is best. Then hunt down some "Band-it" brand craft veneer. Woodworker's supply has it among others. The veneer comes in packs of 8x12 sheets and you glue it with contact cement. I use mahogany for my boards. It's neat to mix woods with a contrasting pattern too. Band-It brand is made by the Cloverdale Company PO Box 400 Cloverdale, Va. 24077