
Maybe you've seen them adorning the underarms of various celeb fashionistas; I give you the Poppie Couture Fold Over clutch. It seems to be your basic trapezoid of fabric with a wire frame closure. What makes them distinctive is the funky fabric choices and their $350-600 price tag.
This bag really isn't that different in concept than the LaRue Bag from Hot Patterns. This one is designed specifically as a clutch, however, and has a 4" wide base.

Act 1: FABRIC CHOICE
So, how would I chose to replicate such a bag? Well, first I would find myself some really awesome pleather, or even genuine patent leather on pig skin. Fabric Mart has five of these left for just $25 and the one skin would be enough to make at least one clutch, with enough left over should you want to make a two-toned version. Heck, Fabric Mart even has the metallic/pearlized leather in two versions should you like to jump on the the gold/silver bandwagon that's so hot right now.
Act 2: PATTERN SELECTION/CREATION
The website gives the measurements of this bag upright as 11x12x4 and folded as 11x6x4. I've looked for patterns and, well, they are slim pickings when it comes to clutches with this shape. However, all is not lost as the solid colors are just two pattern pieces (symmetrical sides and the bottom. We can determine through the bag descriptions that it is 12" tall and 11" wide. These are generous dimensions and should comfortably hold what you need. Grab your ruler, pencil and a couple of sheets of tracing paper and get crackin'!
Pattern piece one: Bag front and back
This piece is going to be kind of trapezoidal, since by examining the sides, you can see that the front and back are sewn together without a side panel piece between. We want our finished width to be 11" at the top and bottom, but we have to account for the slight triangular nature in the lower half of the bag. Also, we're going to do this a la Burda and add seam allowances later.
1. Draw an 11" line representing the top of the bag. Measure down 12" from each end and mark your paper. Draw the vertical lines on each side the horizontal line on the bottom. You should now have an 11" by 12" rectangle in front of you.
2. We can see that the triangular shape of the bag begins at roughtly the half-way point, so on the long sides, measure down 6" and mark.
3. We know the bottom piece is 4" wide and we want a center seam. Therefore, we want to extend the bottom of the panel by 2" on each side, since once sewn, the bottom will be 4" wide. Measure out 2" on each side from the bottom corner and mark.
4. Now draw a line connecting your vertical mid-point (6" on the side) and the new bottom corner.
You should have a pattern piece that looks like a rectangle on top of a trapezoid.

Pattern piece 2: Bag bottom
1. Draw a 4" x 11" rectangle. Easy enough right?
Please note my line drawing, courtesy of MS Paint, is not to scale. However, the numbers are correct.
Add seam allowances to your pattern pieces, probably no more than 0.5" to avoid bulk.
Act 3: EVALUATION
Materials:
1. Roughly 1/2 yard of fashion fabric and 1/2 yard of lining. More if you want to add a pocket or something.
2. The same amount of interfacing, depending on your choice of fabrics. I would imagine skins will need less than lighter weight fabrics. One interesting feature about this bag is that it is advertised as being able to be flattened completely.
3. You would need an internal flex frame of some sort. I found a 12" one at u-handbag.com, which would require extending the width of the bag by an inch. Entirely do-able, I think.
4. A bag bottom, probably card board or hair canvas if you can find it. Since the designer bag is collapsible, I imagine it shouldn't be too stiff.
Act 4: EXECUTION
Since I'm not sure I actually want this bag, I decided I would only make a prototype out of paper, and at half scale, no less ;-) After playing with it for a bit, I think the proportions are correct since it looked pretty good folded over. The thinness of the paper makes it look a little funky when upright.
What do you think? I think I could make it!