I made these two bows from different species of elm, one "good, one "bad", and hope you find this informative. They grew near each other along a ditch, but one was hard, white, clean, works cleanly, and had no heartwood. The other was softer, mostly heartwood, scruffy, stringy, and clogs rasps. The saplings were the same size almost exactly,, thick ends just over 4" dia., so the bows are both 67" NTN, heat tempered into reflex on the same 2" form, same crown, nearly the same width.
The GOOD elm has the leather handle. It is 1/8" narrower overall, has a longer handle/fade section by an inch, side tapers earlier, and still retained 1-1/4" of reflex. It draws 53# and physically weighs just a couple ounces more. Unstrung after shooting it shows very little extra follow. It split hard, but worked easily with rasps and the spokeshave. It shoots an arrow visibly slightly faster.
The BAD elm has the hemp handle wrap. It is 1/8" wider and a hair thicker, and side tapers later on the limb. It refused to hold any reflex during tiller, and in fact gave back about 1-1/4" right off the form. It took most of its set shortly after hitting brace height during tillering. It insisted on bending more about 2/3-3/4 of the way out the limb. After use it shows nearly an inch of string follow, and creeps back to ALMOST straight. It pulls 51#..
So, there ya go. The bad elm probably should have been tillered with a 45 lb bow in mind or whatever. It's not a disaster, rather a shootable bow, but is clearly different wood than the better elm. I don't have full draw pics because I am just getting around to finishing them. As I do sometimes, I left them sitting around too long after shooting in, and now there is a tiny bug hole on the crown of the "good" elm, I have to patch.
Remind me if I forget.