Q&A: RSVPs: Is Using Postcards for Replies Tacky?
Q: Is it tacky to use postcards as reply cards? Postage would be a little bit less expensive, but since I plan on having very traditional invitations, would postcards be inappropriate?
A: Fully traditional invites do generally mean standard reply cards with miniature envelopes. But honestly, as long as the postcards are made of the same paper as the invites with the same typeface, they will look fine and you'll save a little money to boot. Go for it.