George,
How about red oak as a backing? I have so much of that it's insane. It's plenty wide enough to cut a few backing strips with almost perfectly straight grain. I've used it before on youth bows, but nothing heavier than 40#.
Pat,
Love the brown paper bag idea!! Gonna give that a try on some youth bows to test it out. Please keep the ideas coming guys.
While I'm at it.... Anyone ever make a backed tiger maple longbow? I have about 45 board feet of that too. Made a bow with it and it came out at 45#@28". Shoots fairly well but still testing it out. Took almost no set after around 300 shots over 2 days.