The invitation (when closed) measures 4x4, upon opening the invitation you are greeted with a large 8x8 canvas that is perfect to communicate your party details surrounded by fun patterned papers and embellishments.
The foundation of the invitation uses the squash book technique. You can google many tutorials on how to create a squash book. For simplicity, I started with an 8x8 card stock paper, scored it at 4" on both the horizontal and vertical axis. Next, I scored on the diagonal of the square from the bottom left corner to the top right corner. Bring the corner tips together and your 8x8 square will 'squash' nicely to a 4x4 size.
Just remember when you are placing embellishing in your invitation that you do not glue embellishment over these diagonal fold lines as these need to freely move to open and close the invitation.
You don't need to make every invitation the same so this a great opportunity to use up your Doodlebug stash!