Kegan,
If this bow were meant for hunting I would have probably backed it with rawhide to protect the sapwood from getting dinged. But since I'll only be using it for target shooting, I wanted to leave it unbacked because the sapwood is so attractive. I'm not too worried about the back failing because I worked the sapwood down to a single ring (which was a lot of work) and yew sapwood has a reputation of holding up even when violated.