And am not even showing the whole
Grab strong double sided tape and run it along the bottom edge of the flap.
Of course you can make sideways or tent style opening ones (such as A6, DL etc. just to suit the size and shape of topper you intend to use on the front) - and don't fret over folding the money or cheque, the betting is that it will be folded at some point by the recipient anyhow :)
One super fast and easy money wallet - which leaves more time to hop around WOYWW over at Julia's - so why are you hanging around here then? The mulled wine isn't heating in the Snippets Playground yet and the tree wasn't up with lethally and dangerously wired lights last time I dared to peek so go on, shoo!!
Happy WOYWW :)