I find this a very interesting subject especially on this forum. Seems 3 railers only think in terms of FLAT tables. Why is that? Guess that's a topic for a different thread. Anyhow if you have uneven TOPS of your boards that you are going to be placing a SKIN on top of, think SHIMS. I almost never use full sheets of ply as I cut them to fit the width of the road bed I need and then raise or lower the roadbed to get my level, which means I don't care what the table framing looks like. I also only 3/4 in cabinet grade ply. At about $10 a sheet difference I don't want my $ engines and or trains having issues because I cut corners on the table. Just my 2 cents, spend wisely! Russ
A yard with shims under the sheet to take a small dip about mid yard.