Packaging And Embellishments: If you're adding embellishments, or you're mailing more than just an invite plus an RSVP card (we opted to mail more info, because of the destination aspect), keep track of the weight of your invitation suite once it's all packed up. Depending on its size, you may be facing more postage fees than a simple stamp will cover. You can get a postage estimate using a kitchen scale and checking on the USPS website. Through the USPS website I also learned that square invites and envelopes cost more in postage, by a significant amount. It's not worth it.
Letterpress: The designer and paper lover's dream, letterpress is visually lovely and highly coveted all over Pinterest. However, it is expensive because it is a fine art that requires some heavy machinery. Letterpress is the option to use when you want to support the artists making it, not because you think you should. Thomas Printers is a great option for people looking for letterpress invites on a reasonable budget. The other option to letterpress is to build your own, but you better have a serious love for the actual craft. The majority of your guests, sadly, won't know or won't care that your invites are letterpressed.