Please note that all enamel pins are hand made and graded by a person. There are no perfect pins.
A - No noticeable flaws at arms length. Possibly a few specks of dust/debris on places other than the face. Slight underfill or overfill. Screen printing off by a few millimeters. Straight to slightly bent posts where the posts can still be used
B - Noticeable flaws at arms length. Potentially specks of dust/debris on the face. More than a few specks of debris across the pin. Slight scratches in the enamel and/or plating. Noticeable underfill/overfill. Bubbles in the enamel. Screen-printing off by more than 3 millimeters, missing Screen-printing or smudged Screen-printing. Small areas filled with wrong color enamel.
C - Flaws Noticeable at arm's length. Missing enamel. Major scratches in enamel. Majorly smudged Screen-printing. Missing posts or majorly bent posts. Multiple and/or large areas of wrong color enamel fill.