Trees have two main types of wood: heart wood and sap wood. On many trees, only the heart wood is used by fine wood workers. With walnut, the sap wood is a lighter color and is sometimes too soft. This particular board from the Carpenter ant stash was still suitable for a banjo, so I chopped it up for the rim and the neck. I love the hombre look of the two colors of walnut in the rim! The pistachio comes from California orchards and the natural skin head makes for a more rustic look and sound.