If you're not familiar with the term, enamel pins often get a grade assigned to them that reflects the quality of that pin. Because enamel pins are manufactured by hand, not every pin will look perfect and slight flaws may occur.
There's no universal grading system. Often pin makers will have come up with their own grading system so it's important to read through it and take that into account when buying.
I use a three-grade system: My A Grades(“Standard”) are the best of the batch, my B Grades(“Seconds”) have minor imperfections, and my C Grades have larger flaws.
A-grade pins are the best of the batch and the highest quality pins I offer.
They are close to perfect but may still exhibit minor imperfections not visible at first glance, and are mostly only visible under certain light and angles. These could be minor flaws such as:
Example of an A-grade pin:
B-grade pins seem fine at first glance, but under close inspection you can see some minor imperfections. These are perfect for people that don't need a mint condition pin, but just really want the design or want to wear the pin.
Because of their minor imperfections, B Grades are sold at a 30% discount. They can have flaws such as:
Flaws you won't find on the B-grade pin are:
Example of a B-grade pin:
These pins are noticebly flawed and are sold at a 60% discount. They can have flaws such as:
Example of a C-grade pin: