I downsized this from a 6 x 6 folded envelope/card that I saw to a standard 5.5 x 4.25. I created this so that my friend's neice could send out her wedding announcements without the extra postage for square cards.
I added the band to my projects, but the folded envelope could easily be sent in the mail without an envelope. The retired Greeting Glue would be the perfect adhesive. The bottom section perfect for a reply card and directions is what I will use for a gift card.
I think that double-sided paper was made for this type of project.