This is way huge, I know.
I've had more than a few people ask me how I've made bags like this one. I made this to explain it. I think a project like this one can be incredibly frustrating without some guidance the first time.
I do sell these, and other bags like them. Some people may think I'm insane, showing this to everyone. But I don't own this information. Anyone can make a box type purse, either on your own or with a pattern, so this is hardly groundbreaking. As a matter of fact, these instructions could also be applied to making cushions. It's the same concept.
1. Sew welt to the sides, and notch where you want the zipper to end.http://www.craftster.org/pictures/data/500/58334bx_1.jpg
2. Measure between notches to get the measurements for the zipper panel and the boxing strip that goes around the sides and bottom of the bag.http://www.craftster.org/pictures/data/500/58334box_purse_2.jpg
3 & 4. Cut a boxing strip. Here it is 4" wide. Cut two zipper panels, these are 2.5" wide by 21". These measurements will give you a bag that ends up being 3" deep. Cut all lining pieces the same as bag pieces (not pictured). Cut or buy a zipper as long as the zipper panel (21" here).http://www.craftster.org/pictures/data/500/58334bx3.jpghttp://www.craftster.org/pictures/data/500/58334bx4.jpg
5. Sandwich zipper between lining and fabric, teeth side toward the outside fabric. You want right sides together. Sew.http://www.craftster.org/pictures/data/500/58334bx5.jpg
6. Turn and topstitch.http://www.craftster.org/pictures/data/500/58334bx6.jpg
7. Repeat on other side. It should look like this:http://www.craftster.org/pictures/data/500/58334bx7.jpg
8. Sew zipper panel to boxing strip, so it is one continuous piece.http://www.craftster.org/pictures/data/500/58334bx8.jpg
9. Notch centers on all pieces.http://www.craftster.org/pictures/data/500/58334bx9.jpg
10. Sew boxing strip to purse, clipping corners on the boxing strip. Make sure you match all center notches up.http://www.craftster.org/pictures/data/500/58334bx10.jpg
11 & 12. Follow corners to other side of the boxing strip and notch them. Sew the other side to the boxing strip, matching all center and corner notches.http://www.craftster.org/pictures/data/500/58334bx11.jpg
13. For lining, sew all pieces (minus the zipper parts) together. Turn down the top edge of the bag.http://www.craftster.org/pictures/data/500/58334bx13.jpg
14. Put the bag into the lining, wrong side out. Sew the top edge.http://www.craftster.org/pictures/data/500/58334bx14.jpg
15. Turn the lining to the inside, using opening left on the side. Hand sew these side openings closed.http://www.craftster.org/pictures/data/500/58334bx15.jpg
Here it is finished:http://www.craftster.org/pictures/data/500/58334bx16.jpg