So I found a set of 4 chalkboard coasters. I was thinking to use a paint pen on the top one to make my seating cards (instead of spending the extra money on those). And then the stack would be something the guests could take home to use later (since the chalk is included and what person can't use a coaster?). I just don't know anymore. I need something but thought it'd be a cute double-duty idea.
Re: Favor/Seating Cards
Generally, I'd recommend going with something edible as your favor. If you do the coasters, you'll probably end up with a ton left over.
I wouldn't take coasters since DH and I already have a ton.
Most any favor can double as an escort card as long as you attach a tag to it. Dollar Store ribbon and tags with a hole punch won't cost much.