On a bow made for dacron only you should shoot dacron.On a bow made for FF type strings you can shoot FF or dacron,it doesn't really matter.For me I shoot dacron on my older bows for safety and to not shorten the bows life possibly.But on FF type bows,for me I see no advantage to using dacron on them.I like a bow that uses FF type strings and I don't mean for any speed increase a FF offers over dacron.I prefer a low stretch FF type string for the feel of the shot,the bows feels more solid to me.On some bows using dacron it can increase handshock and the bow feel springy to me.And dacron is not always quieter then a FF type string.If a bow is rated for FF I use a FF type string,but if it is dacron only I shoot dacron on it.