Grading Vinyl (LP record albums)

ABOUT ME
I've been an okay user since 1998 and a record collector since 1964. I've also been a record producer since 1984, for Rotary Totem, Regemended, Cuneiform and most recently for Ad Hoc Records.
ABOUT LP "PLAY" GRADING
The only way to properly grade the quality of an LP is by first cleaning it, then playing it. Most records listed on okay are NOT play-graded, so be sure to ask first! The standard grading system was developed by Goldmine Magazine and is reprinted all over the Internet. I will paraphrase here:
STILL SEALED -The plastic shrink-wrap has never been opened. However, if a vintage record is still sealed, then it may be warped or could possibly have been resealed.Consider askingthe dealer to open and play grade.MINT - The shrink-wrap has been opened but the record hasnever been played before.Virtually impossible to find anywhere. Even thoughmany dealers claim this grade, don't believe it!.NEAR MINT - No scratches, no skips, no surface noise at all. Record has been played extremely carefully on a quality turntable. No cut-outs or ring-wear on the jacket! Veryhard to find a record in this shape,butthere are some out there.VERY GOOD PLUS- Some surface noise may be audible at the start of each side. No scratches or skips!Cut-outs or faint ring-ware on the jacket OK, if listed in the description!Manyof the recordslisted on okay that claim to be M or NM are actually VG . VERY GOOD- Minor surface noice thoroughout. Light scratches, no skips. This is the real grade of most records that arelisted on okay.GOOD - Not a "good" thing. Unplayable. Garage sale fodder. Don't bother.
ABOUT LP "VISUAL" GRADING
The vast majority of records that are sold on okay are "visually" graded. This means the vendor has looked at the record but has not played it. As a buyer, you are gambling, because many defects (such as surface noise) cannot be seen by the naked eye! If the vendor uses "Goldmine"-type grades, but has not played the record, he or she is just guessing.I don't want to say that the vendors are deceitful, let's just say that visual grading is always very optimistic. I have found that visually graded recordsmay grade two degress lower when they are played. So, if the vendor says NM "visually", when you play it, you may find thatit is actually a "VG". Sad, but true.
GENERAL GUIDELINES WHEN BUYING RECORDS
Ask questions before you bid. I used to say "buy from experienced sellers", but I have not always found their listings to be correct. Sometimes an inexperienced seller has something really nice and sometimes an experienced seller's listing is incorrect. Set your expectations in advance so you aren't upset when you set the needle on the turntable. Finally... don't run up the price unless you really know what you're getting!