The first osage selfbow I had the opportunity to handle and shoot was a fella's last year at Cloverdale. He kindly let me give it a try on the condition I didn't pull it past my chin. He had taken two years to whittle it and was concerned about it's ability to handle a full draw.
For the life of me I couldn't figure out what that big, thick white patch around one limb was until just recently. It had to have been a rawhide bone. It didn't appear to have been thinned any, just glued and wrapped over a spot he thought was questionable.
I had already dried out two of my deer hides for that purpose and have them ready incase the need for them arises.
Since then I've made a couple of osage self bows of my own. His bow inspired me but, personally, I would rather have deer hide or the like for this purpose than a thick white dog chew.