I have been meaning to try this style of card for ages, then someone at the Chailey workshop (contact firstname.lastname@example.org ) had a decoupage kit with a ready cut screen card in it, so I just had to make one myself :-) I have a few of these Pinned, one example is here. The effect can be varied with your choice of border punch and the whole card folds up to fit in a standard 6 x 4 envelope.
I had previously made a couple of blanks as practice, but not decorated them. The paper is from an Authentique 6" paper pad which I had in my tote, and the flowers are SU punches, as is the bracket punch used to make the 'legs'. The border is a Fiskars punch.
Now there is a standard way to make these, but I have customised mine :-) The standard method is to cut a strip 11" x 6", border punch along one edge, then score at 2.75 inches, then at 5.5 and 8.25. Use the bracket punch at the base of each panel, but line up the card inside it so it only punches half of itself.
But .... I like the pattern repeats of the border to 'line up' with the scoring .... not that I'm obsessive or anything .... LOL. So I customised it. I cut a 12 x 12" cardstock sheet into two 12 x 6" strips. Use the border punch as before. Then count the pattern repeats - there were 29 open scallops on the card above, the nearest number divisible by 4 is 28. So I cut off one scallop and scored a line every 7 scallops.
Really pleased with this - I will photograph the next one step by step for a tutorial, but I think I need to try out a few different borders first :-)