Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
A trick for racking on racks that have rough shelves is to flip the frames and rack upside down. One of our racks is actually an older "official" newman one and it's has these corrugated shelf wings that are very gentle on the frames. The new ones they make are super crazy with some kind of flexible, soft plastic. It's might all seem like overkill but it's not- everywhere the screen rests must be "mesh safe" or you just chase yer tail. I've stuck to that rule and we use nothing but delicate, thin thread mesh on rollers and don't need mesh protector sleeves (just newman yellow tape) or have premature breakage issues. Handling is another story though...hope it all works out Al.
Just to be on the flip side here. WHY would somebody do this intentionally and HOW? how do you take a screen or tape gun and slowly gouge into the tape without going all the way through? it doesn't make sense to me. I would look at a few more things, screen cleaning sink/station, screen racks in dark room, frame holders on the press - there might be a few burrs someplace...it's a long shot and carelessness is still in play here but it just doesn't add up that somebody would do this on purpose. I would do the opposite and offer a reward for the person to find the issue. every single guy is going to watch those screens like a hawk...never know what you may find. this has gone on long enough and rules to live by -keep doing what you're doing, you'll only get what you got.....time to find another route to the issue....but this is just my take....