When I make a garment with a smocked insert, I prefer for that insert to stretch from side seam to side seam so that it's one continuous band across the front of the garment. That just wasn't possible with Kitty Mittens. I am working with an insert which was begun over a year ago, and I am using a pattern (V8062) that a) isn't designed for smocking, and b) is a larger size than I had originally planned for. But that's okay. I can work around all that!
The answer is to add "wings" to the sides of the smocked insert to make it longer. Here you can see that I've added a piece of my fashion fabric to the side edge of the smocking:
This wing will fill up the extra space between the smocking and the side seam, and it really won't even be noticeable because it will be under the arm, and it's the same fabric as the body of the dress.
Once the wings were in place, I added a strip of mini-piping to the top and bottom edges of the insert. You could add your piping to the insert first and then add the wings so that the piping frames only the insert and the seams in the fashion fabric aren't as noticeable. I chose to pipe the wings. The upper piping will be cut off by the armholes and the lower piping will continue to the side seam
I make my own mini-piping. This time I chose a pink/purple/green/yellow stripe cut on the bias. I usually cut my bias strip 1" wide and I use Sinfonia sportweight yarn as my piping cord.
It's 100% mercerized cotton. I bought this 200 meter skein at Hobby Lobby for 3.99 several years ago, and I've been using it here and there ever since. As you can see, there's quite a bit left. (200 meters is a lot of piping!)
Stay tuned. Next up I'll show how I adjust my pattern to include the insert...