Don't forget to stamp the RSVP envelopes you send with your wedding invitations. A colleague of mine stopped by my desk the other day and asked me if the RSVP envelope she received with her friend's wedding invitation should have come with a stamp already affixed. And the answer is yes it should have.
I don't know if it was an oversight on the bride's part or if she thought she could save some money, but you must include a stamp on the RSVP envelope. Don't expect your guests to go to the post office and buy one.
If you want to save some money, talk to your stationer about sending a RSVP postcard instead. You may save money on the printing because it's one item instead of two - RSVP card and envelope - and you'll definitely save on stamps. Postcard stamps now cost 27 cents each.