rsvp card address stamp??

I would definitely check Etsy. We got a return address stamp from Etsy and I remember seeing some stamps that seemed pretty big. It may also be possible to contact the seller if you find one you like and ask if they could make a larger version.

Can you just buy labels and print them yourself?

Etsy has a TON of great options for stamps.

I ordered a stamp on Etsy for our invites, it went on the front flap. It didn't work for RSVP envelopes though. It was larger than the typical corner ones.

This is what we did - clear ones, so they didn't look "obvious" on the envelopes. We did the same thing for addressing the invitations and thank you notes. It worked out well for us.

I bought a stamp at PaperSource. I used them as return labels for the STD. Some got misread by the post office and sent back to us so it is obviously large enough. The RSVP envelopes are small anyway so printing another label wouldn't make the print any bigger.

As others mentioned, ETSY!

I got one from Etsy, free shipping, I believe i spent $25 total and totally worth it!

They have a variety of designs; I chose a simple but cute one. Check mine out below!

address stamp

Etsy is a great option. Another is clear Avery labels and printing them from home.