Grade A:
Standard grade. No apparent issues. These would be the best quality pins of the batch.

Grade B:
Minor imperfection such as a minuscule dot/dust, scratch, or imperfect polish. You likely won't even notice (unless you really, really stare at the kitty).

Grade C:
Obvious imperfection/s such as a speck of misplaced color, under filled enamel, or color bleed. Overall the kitty still looks great and is a steal for deal seekers! Imperfect kitties are uniquely their own and need loving homes too. :)