I got the following information from Phoenix Mailing LLC in an email today – good information if you design any sort of mailers (including postcards) and have reposted it with their permission.

On January 5, 2013 there will be some new rules to contend with at the post office.

1. Postage is going up. A first class stamp will be 46¢ for 1-2 ounces
2. Bulk rate postage will go up approximately .004¢ each
3. The new IMB barcode will be the only one allowed on automated mail and must be included on reply cards and envelopes

New requirements for self-mailers not inserted into an envelope

1. The maximum letter size for folded self-mailers will decrease from 6 1/8″ x 11 1/2″ to 6″ x 10 1/2″
2. Final fold at the top of the folded self-mailers willno longer be allowed – as well as tabs at the bottom of the mail piece.
3. Two tabs at the top of folded self-mailers will be required instead of the one allowed now.
4. Remittance envelopes must be inserted into the first fold of a quarter-fold self-mailer.
5. Quarter-fold self-mailers will need paper weight to be at least 70#.
6. For 3-panel self-mailers, the mailing address must be on the center panel, with the final fold creating the non-address side.

Not following these rules meas your mail will be non-machinable and WILL COST MORE IN POSTAGE!