Posted By:
Al CrisafulliRegardless of the grading company, if they find evidence of alteration, they will reject the card as having been altered. If they do not find evidence of alteration, they will grade the card.
It is entirely possible for a card to be altered or restored without leaving any evidence. All you need to do is look at many of the major auctions and then read the disclaimers to know that.
Part of grading a card does not involve searching through every conceivable auction that's happened in the past to try and figure out if that particular card had once been in lesser condition. A collector submits a card to a grading company, the grading company makes an assessment of the card, and then either they put it in a slab, or they don't.
-Al