| Generally speaking, Near Mint cards are free of any noticeable damage to either surface. Near Mint cards may appear with one or two minor scratches, blemishes, or nicks/impressions when under close inspection, but should otherwise be indistinguishable from like-cards. The edges and corners of Near Mint cards must be pristine and without tearing, crimping, folds, or an exposed inner layer.
Most modern-era singles (printed within the last fifteen-to-twenty years) start at Near Mint. The “Mint” condition is usually saved for cards judged upon their collectability, rather than playability – think Alpha, Beta, Unlimited, Revised, Arabian Nights, and Antiquity sets, particularly those that fall under the “Reserved List” (The “Reserved List” refers to specific cards that Wizards of the Coast as guaranteed to never reprint in a paper, tournament-legal form. The “Reserved List” covers the sets from Magic’s inception (Alpha, 1993), up until Urza’s Destiny (1999). See: https://mtg.gamepedia.com/Reserved_List). When purchasing high-profile singles, it’s better to know the “grade”, rather than just the assumed condition - after all, a single point difference can alter value by hundreds, thousands, or tens-of-thousands of dollars. Rest assured - the two reputable grading services, Beckett and PSA, always verify whether a card is genuine.
Although most “pack-fresh and sleeved” cards will be Near Mint, there are exceptions: factory defects such as off-colored images or text-boxes, over- or under-inking of text, package-sealing mishaps, off-centered borders, or a missing holofoil stamp (for Rares and Mythic Rares produced in Magic 2015 and onward) can all lessen a card’s condition to Slightly Played or worse. Here, condition depends on the type of defect and its prevalence. When selling cards with factory issues (a.k.a. “misprints”), inform prospective buyers by creating a note – even if the error is obvious from your listing’s picture. Some misprints are highly-valued, so make sure you do your research.