I found this grading system here
http://emorysmemories.tripod.com/websale/condition.htm. It should give you some insight.
COMIC BOOKS / MAGAZINES
Graded by Overstreet Grading Guide Standards. Grading takes into account the whole issue, not just the cover. That may sound like a "no-brainer," but some folks do base most of their grade on the front cover, which is silly. When in doubt, refer to the Overstreet Grading Guide to see what flaws are acceptable in what grades. I always do and I've been grading comics for over 30 years. 30+ years doesn't make me perfect, but my eyes are pretty darn good at spotting defects. Here's a brief grading overview:
M = Mint. By nature, anything manufactured has flaws, so I find this grade difficult to assign. There are an incredibly small number of newsprint comics that I'll grade as Mint. Most of my Mint comics are on high grade paper and are priced at 120% of NM 9.4 guide value.
NM/M = Near Mint/Mint. This is typically the highest grade I assign, but what most people refer to as Mint books. These are top of the heap for paper collectibles and are priced at 110% of NM 9.4 guide value.
NM = Near Mint. The issue can have a few small stress lines on the spine, a very minor corner chip or crease, tiny color flecks or bindery tear. No other defects allowed. For the most part, the minor defect comes from mechanical production. My NM comics are equal to the Overstreet 9.4 number grade. NM and better comics are commonly referred to as "investor grade." While I recognize comic books as investments, deep down I keep hoping people actually read them for enjoyment. This grade is priced at 100% of guide value.
VF/NM = Very Fine/Near Mint: This grade falls between VF and NM. These issues have a few more stress lines or a bigger bend/chip to keep them out of the NM grade. The front cover (f.c.) may not be perfectly centered, but can not be off-square by more than a quarter inch. The back cover (b.c.) or spine may have a minor scuff. I typically put NM issues with heavier stress lines at the staples into this grade. Comic book insides must be no worse than off-white, or tan for newsprint magazines. Most of my best Marvel Giant-Size issues and squarebound magazines fall into this grade because of the way they are manufactured - what I call sloppy spines. Magazines like TV Guide, National Lampoon, Penthouse, etc. may have a minor cover abrasion where the issue slid over another issue. VF/NM issues require more than a cursory look to spot defects and are still extremely collectible. For comic books, I take an additional 10% off the calculated value.
VF = Very Fine: An excellent copy with outstanding eye-appeal. First sign of a lack of complete flatness in an issue may be present, as well as cover wear. Slight wear at the corners or along the edges. The spine may have a few more transverse stress lines. A light half inch crease is acceptable. Pages may be yellowish/tannish. Magazines like TV Guide, National Lampoon, Penthouse, etc. may have a cover abrasion where the issue slid over another issue, but nothing severe. For comic books, I take an additional 15% off the calculated value.
F = Fine: An above average copy that shows minor wear, relatively flat, corner dings may be present, but no major creasing or serious defects. Eye appeal reduced because of noticeable surface wear and accumulation of minor defects along the spine and edges. A Fine condition issue has been read many times and has been handled with moderate care. Magazines like TV Guide, National Lampoon, Penthouse, etc. may have a noticeable cover abrasions or production ink smears. For comic books, I take an additional 20% off the calculated value.
VG = Very Good: The average used (not abused!) issue. Shows reading wear, spine stress, center crease, and light spine roll. Discoloration and soiling is allowed. Small piece may be missing from a corner, but no chunks from the cover are allowed. Store stamps, name stamps, arrival dates, initials, bindery and printing defects have no effect on this grade. However, I will always note if these are present. Cover and interior pages may have minor tears or folds. Cover or centerfold may be loose, but not completely detached. If minor tape repair exists, I will note it. Comic books from the 1970s that are graded VG are done so because of edge creases or corner dings, not because of excess handling. For comic books, I take an additional 25% off the calculated value.
G = Good: All pages and covers are present, though bits may be missing, but nothing that makes the issue unreadable. Cover or centerfold may be detached. Comics may be creased, scuffed, abraded, show heavy staple stress, marked, stamped, or taped. This grade can have a large accumulation of defects, but the issue still maintains structural integrity. This is the lowest grade accepted by many collectors. I try to note all defects. For comic books, I take an additional 35% off the calculated value.
Fr = Fair /
Pr = Poor: The issue not be entirely complete (ex: missing an ad page), but should be readable. These issues are heavily worn, taped, marked, stained, and may have coupons cut. A Fr book may have up to 1/3 of the cover missing. I have a few of these listed and they are basically Golden and Silver Age reading copies. For comic books, I take an additional 50% off the calculated value.
O/C = The cover is off-center. Overstreet identifies this as a bindery defect. For me, an O/C cover will drop a NM or better issue to VF/NM providing that the cover is O/C by no more than 1/4 inch.
f.c. = front cover / b.c. = back cover
Store Name Stamp: The store name stamp mentioned on a number of Silver Age Marvels is 3 lines and appears on the top of the back cover, taking up approximately a 2.5 x 3/4" space. It reads:
Wally's Paperback Book Exchange
2301 S. Craycroft
Tucson, Arizona
Conditional Statements: Example, VF: cover loose at bottom staple. This means the issue is in VF condition with the defect noted. It is not graded VF because of the defect and is not priced as VF. In this example, this issue would be priced at a VG value.
Issues graded F/VF or VG/F are simply done so to denote that they are slightly better in appearance than the lower grade. I don't use the plus+ or minus- system with comic books or magazines. All issues in these conditions are priced at the lower grade (ex: VG/F looks nicer than VG, but still carries a VG price). Comics from the '70s that are graded VG are done so because of edge creases and corner dings, not because of excess handling. As an example, a comic book from 1975 may look NM over 90% of the issue, but have a substantial corner ding that affects the entire book and drops it several grades to VG/F or VG.
Linear Mode
