The 'quilt' is not a finish, but the grain pattern in a slice of maple veneer that is applied to the top of the guitar body. The ripples are produced by distortions of the grain by stress, at the base of the tree trunk, or where a large limb meets the trunk. This wood has a particularly high density, which tends to give it a 'bright' sound. A slab of this wood, say 1/2" thick, can add some clarity to an otherwise dark-sounding wood like mahogany. This is the combination used in the Les Paul. If the layer is nearly paper-thin, it will not significantly affect the tone, but is merely decorative.