I'm a self bow guy, with a few sinew backed ride alongs over the years. Hard backings are something I don't have enough experience on to be of much help so let someone else answer those questions. I will say this, self bows are an art in and of themselves and they are, when made well, complete without any backing. My advice to folks is usually the same, get the bow making basics down pat first, then add to those skills all of the various tangential skills like backings of different types. The foundation of this craft is the ability to get that wood to bending where and how you want it, without it breaking or breaking down. Beyond that, if it IS bending where and how you want it, was that the right call for this particular bow?? Once you have gotten your head around those things, and become competent at them, all kinds of directions you can go. Just my opinion for what it's worth.