The USPS issues most postal cards in two formats. There are single cards. And there are sheets of cards, typically sheets of 40. I’ll ignore paid-reply cards for the purposes of this discussion.
In 2012, the USPS is going to issue postal cards in a sheet of 4 cards with mico-perforations so that the cards will separate easily. The target audience for these cards is people using a home computer who would like to print on postal cards using their printer. Printing single cards is difficult because the small size easily gets jammed in the printer. Obviously, sheets of 40 cards won’t fit in a printer.
The sheet of 4 cards will be 8.5 by 11 inches, just like a standard sheet of paper.
For collectors, there will be two collectible varieties of some postal cards. There will be the usual single card version. And there will be a single card with micro-perforations. Some collectors may want to collect the sheet of 4 format too.