What does B/C-grade enamel pins means?

As much as efforts are made to ensure the best quality, sometimes minor defects occur during the manufacturing process. We regret to inform that this is beyond our control. For pins with such defects, we have listed them as B/C-grade to reflect their less-than-perfect finishings. However, this does not affect their functionality.

B-grade

Faint scratches (visible under close distance/bright lights)

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

C-grade

More visible scratches/multiple scratches 

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

Missing colour fills