I just made my FIRST boxy bag yesterday-it was a quilt guild challenge using random drawn paint chip colors. Here is a picture of it. We used the boxy bag directions that dakotamaid mentioned:
http://kelbysews.blogspot.com. Here are my tips after making it: follow the directions step by step. I used two layers of mid-weight fusible interfacing, ironed onto the back side of the outer fabric only. Be careful to center the zipper, and have it right side up. The only struggle I had was getting the second side of the zipper sewn on right--the only way I can describe it is that the outer fabric and lining are not nestled together during this part, each of them are separated into 'loops' when sewing on the second zipper side, then it is turned wrong side out and they are back side to side again. Otherwise, Kelby's directions were clear and spot on.
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