I quilted the 22 inch improv panel with an elongated serpentine stitch on my sewing machine.
I created an envelope closure, but this time I quilted the back of the pillow as well. I bound the edges with single fold binding, machine stitched. This construction makes for a really sturdy pillow. I was able to overstuff the pillow as a result. Who knew 22 inches isn't a common size for pillows? Lucky for me, a squishy 24 inch pillow form works perfectly. I think a simple lined back would gape open under the pressure, but this fully quilted pillow holds the form beautifully.