Wasn't sure whether to put this here or the barbershop, but decided on here....
I picked up a DMT 325 grit plate for lapping my stones. Also figured it could prove useful for knives in rough shape. I also got a DMT 600 at the same time, primarily for use on knives that don't need to start on the 325, but before hitting something really fine.
Thing is, the one label "600" distinctly feels courser than the one labeled "325." I would be absolutely sure that one was packaged incorrectly if the plates themselves were not marked.