Anyone serious about collecting Star Wars cards (or any cards for that matter) will only accept cards that are in Mint or Near Mint condition. I only collect and trade Mint (MT) or Near Mint (NM) cards.
Many of the vintage Star Wars cards are NM condition simply because printing standards back then were not as exact as they are today. You can buy a wax pack of vintage 1977 cards, pull them out of their pack and place them in protective sleeves and still only be NM. So for this reason it is acceptable by most collectors to accept vintage cards fresh from the wax pack regardless of condition.
Meanwhile it is uncommon for modern cards to suffer from as many printing defects due to quality of equipment. However, another good example are the Topps 2002 Attack of The Clones movie cards; these cards are of low quality and it is very hard to find any common cards without rough and chipped edges making nearly every card a NM card. Below are some examples of cards I found in storage that didn't make it into my collection or trade lists.
Mint (MT): A perfect card. Well-centered with parallel borders which appear equal to the naked eye. Four sharp, square corners. No creases, edge dents, surface scratches, paper flaws, loss of luster, yellowing or fading, regardless of age. No imperfectly printed cards – out of register, badly cut or ink flawed or card stained by contact with gum, wax or other substances can be considered truly Mint, even if new out of the pack. Generally, to be considered in Mint condition, a card’s borders must exist in a ratio of 60/40 side to side and top to bottom.
Near Mint (NM): A nearly perfect card. At first glance, the card appears perfect; upon closer examination, however, a minor flaw will be discovered. On well-centered cards, three of the four corners must be perfectly sharp; only one corner shows a minor imperfection upon close inspection. A slightly off-center card with one or more borders being noticeably unequal but no worse than in a ratio of 70/30. Yellowing or fading would turn an otherwise mint card into NM.
Excellent (EX): Corners are still fairly sharp with only moderate wear. Card borders may be off center as much as 80/20. No creases. May have very minor gum, wax or product stains, front or back. Surfaces may show slight loss of luster from rubbing across other cards. Dark bordered cards may have one or two small nicks.
Very Good (VG): Shows obvious handling, but still looks nice. Corners may be rounded or perhaps showing minor creases. No major creases on a VG card. Surfaces may exhibit loss of luster, but the printing is intact. May show major gum, wax or other packaging stains. No major creases, tape marks or extraneous markings or writing. All four borders visible, though the ratio may be as poor as 95/5. Exhibits honest wear.
Good (G): A well-worn card, but exhibits no intentional damage or abuse. May have major or multiple creases, however, creases are not so deep as to show the underlying paper. This card is completely readable, has not been written on, and has no tape marks or holes. Corner rounding may extend well beyond the border.
Fair (F): Shows excessive wear, along with damage or abuse. Will show all the wear characteristics of a Good card, along with such damage as thumb tack holes in or near margins, evidence of having been taped or pasted, perhaps small tears around the edges or creases so heavily as to break the cardboard. Backs may show minor added pen or pencil writing, or be missing small bits of paper. Still basically a complete card.
Poor (P): A card that has been tortured to death. Corners or other areas may be torn off. Card may have been trimmed, show holes from a paper punch or have been used for BB gun practice. Front may have extraneous pen or pencil writing, or other defacement. Major portions of front or back design may be missing. Not a pretty sight.