Soft cornice!

The client wanted valances with a cutout bottom shape that I thought could be best achieved with a soft cornice.  Though I've made soft cornices before, I was concerned about this particular shape- I was afraid the rectangles would curl.
I consulted the pros at the CHFA forum who gave me excellent advice, re-watched the soft cornice instructional DVD by Donna Skufis, and then got to work on a mockup.

I chose a good quality cotton similar in weave, weight, and texture to the one we'll be using for our client.   In the end, this turned out to be more than a mockup- it's a completed sample.

This valance has four layers: face fabric, interlining, Skirtex buckram, and blackout lining.  Microcord finishes the bottom edge.  The most important lesson I learned from my mockup: for the client's product, I will stabilize the fabric first, to be sure I can clip closely into the inner corners without the risk of fraying. 

My fears were unfounded- the rectangles left from the cutouts did not curl at all.  I was prepared to reinforce them with either cardboard, or wood slat fragments, or more skirtex, but they lay perfectly flat on their own.

The bottom edge on the back is finished with gimp.

I'm thrilled with how this came out!

I'll be starting on the real thing soon, using this pink and white print.