I use Mint only for sealed records. That does not mean that the record inside has no flaws, as noted by tomic601. On sealed recrods of value, I offer buyers the option of having me open it after they buy it. If the record is not MINT, then I give them options. So far, no one has taken me up on that offer.
Occasionally I will use Mint- for a record that has obviously not been played or is perfect, but opened.
NM for me is a grade I will give records that are virtually flawless. They may have a few very light and hard to see sleeve micro-lines. It should play dead quiet or with just a few light tics which could be inner sleeve dust or even static.
I granulate my gradings from there and offer a visual grade and a play grade because they often differ wildly for various reasons.
