…..A chip inside the bubble mailer causes it NOT to be uniformly thick....when I lived in Vegas thats what I was told by the PO...however, mailing 6 chips in a cut six pocket page in a OOO, made it uniform, so a large non machinable envelope, at least to a PO employee that I would go too most of the time. of course others would say "anything in a bubble mailer is automatic parcel" or "it cant be more than a 1/4 thick"