I'm not sure what they call it them for sure. My longbow has an arrowrest and sideplate that is pretty worn right where the arrow rest. My arrow sits in the groove maybe up to half the arrow diameter and about the same on the side plate(if that's what you call it. I'm just wondering if they need to be replaced when they get to that point or is it all right as long as it's not rubbing against to the point that it wears into the bow itself. thanks- Steve

I have some rest material on some bows seem to last for years and on others it seems it is about a 6 month and then time to replace. I do iot when I start to see the arrow drag marks have worn a spot on the side plate or the rug....

Yours are probably ready for replacement, but Bill's got it right.  Some materials need replacement more often than others.  As for wearing on the bow, I suspect you'd have to shoot an awful lot of arrows for that to become anything other than a cosmetic issue.  The biggest issue I see with what you've described is that your arrows are contacting a whole lot of the rest and side plate material.  A single point of contact is best as it will affect arrow flight less.  If you're rubbing all over the arrow, you could be adversely affecting your arrow flight.  On the other hand, if you're hitting what you're aiming at, why fix it if it ain't broke!  If it sounds like I'm saying there's no absolutely right or wrong answer to your question, you're right, but personally, I'd replace the rest material and the side plate.

if it sqeeks or sqeels, replace it, if not, but still shoots good don't.