Authenticity guides

A valuation is only as good as the item behind it. These are the checks a collector can run themselves, each against a primary source.

• How to verify a graded card's certification numberEvery major grader publishes a free certificate lookup. Checking a cert number against it is the single most reliable authenticity test available to a collector, and it takes under a minute.
• Altered and trimmed cards: what alteration actually isTrimming, recoloring, pressing and rebuilt corners are the alterations that move a card several grades. They are invisible in most listing photographs and they are why measurements matter.
• Using population reports to check a seller's claimGraders publish how many copies of a card exist at each grade, free. It is the fastest way to test a rarity claim and to notice when a price makes no sense.
• Buying remotely: the signals worth acting onMost losses on a remote purchase come from a small number of avoidable patterns. None of them require expertise to notice.