What does Grade B/C enamel pins means?

It is normal for enamel pins to have minor defects due to the manufacturing process. However, this do not affect their functionality.

Grade B

Faint scratches (visible under close distance/bright lights)

Mild uneven surface finishes (e.g. not uniform to the touch)

Grade C

More visible scratches/multiple scratches 

Uneven colour fills/surface finishes (e.g. smooth and rough)

Missing colour fills