Maybe a stupid question but: Is it rude if some thank you cards are different from the others? I ran out of the ones I bought and only have a few left to write so I was just going to use blank notecards I already have. It seems silly to go out and by a whole other box of fifty so they match when I have plenty of perfectly good notecards here, but I just wanted to make sure that it wasn't tacky or anything. I'm probably overthinking this, right? I'm just super paranoid about appearing rude to people.