Some of the jelly roll strips are used for the pieced binding. Leftover strips and a matching charm pack are used for the pieced back. While neither is necessary, they both add charm to the finished quilt.
The quilt above is by Lisa of Making It Up As I Go Along and the ladies of the Peace Circle. This group quilt has one more row to make it longer. Extra blocks were used on the back and a solid was used for the binding. See more here.
This is the pattern designer’s version, and the back she provides instructions for.
The finished quilt, as designed by Melissa Corry, is 53″ x 53″. It takes one jelly roll for the front and one charm pack for the back. You’ll need a second jelly roll to make the quilt larger.