I thought that the flap was a great idea for a little bit different card. You know that I'm always in search for some unusual folds and designs.
And here are the dimensions:
In Old Olive you will need 4 1/2 by 5 1/2 for the back, 2 1/4 by 4 5/8 for the flap (scored at 1/2), two pieces of 4 by 2 1/2.
In Whisper White you will need 4 by 5 1/4 for the back, and two pieces of 4 3/4 by 2 1/4.
And here is the inside! I got to use my Botanical stamp set! So exciting!