A lot of the value of a card is determined by its condition.  Many factors go into grading, including centering, corners, and image clarity to name a few.  For a fee, a card may be submitted and graded on a scale of 1 to 10.  The main 3 grading companies are Professional Sports Authenticator (PSA), Sportscard Guarantee Coporation (SGC), and Beckett.  Grading is somewhat subjective, but the following contains the industry grading standards.