WALNUT: black .55. Semi-ring-porous, easy to work, elastic for its mass, similar in performance to cherry, but more tension-safe. Will try to chrysal where cherry won’t. A wonderful, overlooked bowwood. Bows can be all sapwood or all heartwood, or mixed, sapwood taking a bit more set in compression. The off-white sapwood can be worked down to 25% or so of limb thickness, creating appealing contrast with the almost black belly. Very high heartwood extractive level, so as with similar woods, it may be more resistant to water absorption. It’s reported not to warp with rising and falling humidity, possibly for this reason.
WALNUT, European .56. Design as per Black. Not as pretty, but makes a nice bow. Strong enough in tension to tolerate being a “backward” bow: the crowned sapling surface as belly, the split back surface tillered.
hope this helps, onemississipp.googlepages.com, this will give you a list of bow woods and non bow woods and their characteristics, Bub