Slackbunny, I would consider backing a red oak bow with hickory to get a bow that performs better in high humidity. Hickory is extremely strong in tension, and the cross-linking of the fibers allows it to put up with a level of ring violation not possible with other woods, so it makes really good sawed backing. However, it loses it's compression strength in high humidity, and can take alot of set if you don't keep it dry. If you were to back hickory with red oak, you would get a bow that takes alot of set in high humidity, and has very little strength in tension, so is likely to fail on the back. It would capitalize on the weaknesses rather than the strengths of the woods. I would like to try hickory backed cherry some time.