My original board for FASA game uses plastic window screening for the grating. Cutting squares for a gazzilion bases would be no problem.
Now, if you try to do the board the same way I did, another story entirely...
After gluing the proper sized piece of screen to a bit of plywood, I made a small 'tool' from a bit of sprue with a notch cut down the center, and put a bead of modeling putty in the groove and ran it down to make the edges of each floor plate. TOOK FOREVER.
@CV Damn, those ARE pretty...
I think Epicast did something similar, but I don't recall that quality. Course, maybe it's just your painting... ;->=
Doug