My tutorial shows you how to make French Seams when constructing a Fabric Box as first shown to us on http://seaside-stitches.blogspot.com...-tutorial.html.
First you make your quilted square what ever size you want. My example is a 15" square. Determine which side you want to be the inside of the box and which will be the outside. Fold your square in half, the inside facing each other. Example corner is marked at 3" (this turned out to be quite a tall box).