response card envelops?

Is it tacky to use labels on your response cards? We are making out own invitations & the printer is messing up the response envelop when we print I said just print it as labels


Also do we also have to put a return address being that we know there is a stamp on it because we put it there and its goong to us??

I had trouble printing the envelopes too...so I made an outline of the envelope on a piece of paper and then customized the size of the envelope until it printed the address to where I wanted it to be. Are you using WORD? I found that program to be the easiest.