Heartwood

While most flame maple tops are constructed of maple sapwood, which is the outer portion of the tree, the part that is living and growing, heartwood is the dense inner part of the tree that supports the structure. It is only rarely used in constructing tops, and then almost always painted over. However, the heartwood of the evergreen tree species, Diospyros, is where the best ebony is found. Because of its density, ebony is one of the few woods that sinks in water, making it an extremely good choice for fingerboards.