In my area I usually have to buy cryovac multi-packs of spareribs so can't get a good look at each rack to try and get something with relatively even thickness. Lately I've received racks that seem to have an extra layer of fat and then meat on top and these never cook well for me. That fat stays a bit stringy and chewy. Is this common and if so what do you do? Today I tried to filet off that extra layer but it didn't go as easy as I expected so I stopped to avoid butchering up the rack. And the results were as expected - that extra layer was a real detractor on the finished product.