Posted By:
DavidI have no familiarity with PSA or SGC's authentication processes, so am not in a position to comment on what they do or don't do.
The resotored cards that were just talked about had the corner(s) restored to normalcy by added paper fibers from other (low grade) cards, usually to always from cards from the same type (Goudey to Goudey, etc). I have seen restored Goudeys, Diamond Kings and wouldn't be surprised if there is a T206 or two out there. All were big name cards, like Ruths, 33G #1 Benough, etc, and were restored to Mint, Nrmt-Mt or similar highest grade. The person who did this restoration did not do it to deceive anyone and I have often seen them offered for sale while being represented as restored. By the way, the original restorer had to quit because he became allergic to the toxic adhesives needed-- and he would put a small dot on the back of each restored card.
On a practical level, these particular restored cards are easy to identify by any collector, as there is a difference in opacity ('see through' effect). When held up to a light, like a desk lamp, the corners are much more see through than the rest of the card.