Originally posted by Rob DiStefano: if your bow's bowyer doesn't recommend using hmpe bow string fiber, case closed, stick with dacron (polyester)!as chad has said, 450 uses uber non-stretch vectran, and it's also a larger diameter strand than most bowstring threads.i see no viable reason to mix polyethyelene (hmpe) and polyester (dacron) string fibers. makes no sense since the two are apples and oranges and the dacron is just thickening the bowstring. i can't imagine why anyone would wanna do that?