I only buy the "full" sheets. Been buying them for over 10-years and have never seen PB removed, yet. Perhaps I've not been buying long enough or do not look hard enough.

BTW, the USPS will buy back any moistened stamps or stamps that are stuck together (at least they do in Loxahatchee ). I think their reasoning is because the stamps cannot be used with the original gum gone, as tape is not permitted to affix stamps usd as postage to envelopes or packets - or whatever.

JB