Trying to make one of the old French country style serving boards. They're typically round or rectangular and thin - no more than 1/2" thick. They all have a strap of wood inset, maybe 1" wide, running perpendicular to the woodgrain of the board on one side.

I put an image below and hope that works. You can see one here: https://lh3.googleusercontent.com/pr...BNFPwNmxQmcuLg

I've tried several. Every one has cupped horribly. Not a little, a LOT - a 10-12" board will cup at least an inch on each side. The inside of the cup is always opposite the strap. It happens regardless of the species of wood (have used white oak, hard maple, American chestnut and cherry), the size/shape of the board, how dry the wood is and the humidity when it's built. I've cut the wood and let it sit before flattening and assembly and cut, flattened and assembled right away. Always the exact same result.

I can only imagine they're held in with glue. I can't see any joinery or pins.

I get there's wood movement and the panel will shrink and expand across it's width and the strap won't move along it's length. I've made ones without the strap that are fine. But, with the strap, massive failure.

How do you get these things to stay flat? There's so many of these old boards, there's got to be a way. I'm stumped.

Suggestions, advice and secrets appreciated! Thanks in advance.

frenchbreadboard.jpg