My wife and I hbuilt a new house two years ago, so I spent the first winter building a darkroom. When the lumber yard delivered the sheetrock, they used a damaged sheet of 1/8" hardwood wall paneling to protect the bottom sheet of sheet rock from being damaged by the bet of their truck, and they left the paneling with the sheetrock. This paneling is a laminated material - a nice hardwood (mahogany?) skin over a fabricated substrate.

This summer I had to make a board for by Zone VI. I bought a strip of 4" x 1/8" basswood at the lumberyard. Cut a 4x4" square with a hole for the Copal 0 shutter. Then, I cut a piece of the paneling 3.5" square, and drilled a hole in the center of it that is larger than the ouside diameter of the retaining ring on the lens. Then, I glued the paneling to the basswood making sure that the grain of the basswood is at 90deg to the grain of the mahogany paneling. Finally, stained and varnished the basswood, and painted the back a flat black.

I've only used this for a few months, but so far it has served me well. It was fun to make and was far less expensive than purchasing a new lensboard.