Artist Trading Cards
"As their name indicates, ATC are collectables, a brilliant idea born of the older sports-themed trading cards. The one rule that makes an ATC derives from their origins: the dimensions of the ATC must be 2.5"x3.5", or 64x89mm. "To this rule are appended a couple of conventions. First, an ATC mustn't be sold, only exchanged, as the whole essence of these tiny works of art is about artists meeting (by correspondence or online if need be) and exchanging their works, thus meeting many artists and getting exposed to many personal styles. Second, on the back of each ATC the artist writes part or all of the following information: name, contact information, title of the ATC and number (1/8, 2/8...) if it's part of an edition. By definition ATCs are made in limited numbers, often no more than one of a kind. Unique ATCs are called originals; sets of identical ATCs are called editions and are numbered; sets of ATCs that are based on one theme but that are different are called series. Don't be intimidated by the concept of small editions or originals: very few people are anal about this. What most collectors really want are cards that were made with care. Based on that, numbers are meaningless.