When buying from dealers, make sure they follow strict IBNS standards. Paper is clean and firm, without discoloration. Corners are sharp and square, without any evidence of rounding. An uncirculated note will have it's original, natural sheen. May show very slight evidence of bank counting folds at a corner or one light fold through the center, but not both.
Paper is clean and bright with original sheen.
Corners are not rounded. May have a maximum of three light folds or one strong crease. Paper is clean and bright with original sheen. Corners may show only the slightest evidence of rounding. There may also be the slightest sign of wear where a fold meets the edge.