Some timbers can be exceptionally heavy. In the original run of Gibson Les Pauls, which had mahogany backs and maple tops, the weight could vary from just under 8 pounds, all the way to a whopping 11+ pounds. That’s because each piece of mahogany has a different density, and density equals weight. To help keep the weight down on some guitars with mahogany bodies, hollow chambers are sometimes carved into the wood before the top is glued on. Some manufacturers also use specially designed acoustic chambers to help tune the resonance of certain guitar bodies.