The only "official" (note quotes) grading standards are those the ANA publishes in "The Official American Numismatic Association Grading Standards for United States coins" published by Whitman (I believe the latest is 6th edition).
TPGs tend to use this as a guide, but have developed their own subset of standards (I almost said "substandards" -- oops :-)) that they rely upon more heavily and standards do change slowly over time.
Much of grading is subjective. It is an art (qualitative), not a science (quantitative) and especially so at MS grades. Similarly, much of the "one TPG is better than another" or differences in grading standards between the big 4 is a matter of opinion and reputation rather than quantitative fact.
As I've said before, I'd love to see an ISO standard proposed for grading. However, with the squabbling that would ensue, I would not hold my breath. :-)
TPGs tend to use this as a guide, but have developed their own subset of standards (I almost said "substandards" -- oops :-)) that they rely upon more heavily and standards do change slowly over time.
Much of grading is subjective. It is an art (qualitative), not a science (quantitative) and especially so at MS grades. Similarly, much of the "one TPG is better than another" or differences in grading standards between the big 4 is a matter of opinion and reputation rather than quantitative fact.
As I've said before, I'd love to see an ISO standard proposed for grading. However, with the squabbling that would ensue, I would not hold my breath. :-)




















