Wedding Thank You Cards Send Thank You Cards Before The Wedding?

Send thank you cards before the wedding? - wedding thank you cards

I'm getting married in about 3 weeks. Some people who can not attend the wedding and sent gifts. Thank you cards for my friend and I have taken a photo at the wedding with a sign that says, thank you, we will thank you with the image on the printed cards. Is it fair to wait until after the wedding, those who have already been sent, thanks to donations, so they send the card? Or has to wait too long - Should I buy a regular thank you cards to people and send them directly?