Once the wedding is over, the honeymoon is done and you've started to settle into your life as a married couple, it'll be time to send out the thank-yous. If you're going with monogrammed cards (as many modern brides do), you're going to need two different sets: One with your maiden name (or initials) for the gifts you receive before the wedding, and another set with your married name for those you receive on or after the big day. Of course, if you decided to keep your name, you'll only need one set, though you may still want to separate them into before and after cards, if only to help you keep track of which notes you need to send out first.
Like anything else that's wedding-related, compiling a complete wedding stationery suite may seem somewhat intimidating. It's one of those little items that may be an afterthought or a nice touch for your guests, but it will likely require a lot of time, attention and work to get right. However, as long as you have fun with it and don't allow yourself to become overwhelmed, selecting a stationery "wardrobe" can be almost as enjoyable as choosing your wedding dress -- and you won't have to worry about how those envelopes fit in a few years!