Cover the Side Panels
Hand-fold and iron the seam allowance for the second coutil layer and prepare to cover it with ribbon.
If you are using cover fabric instead of ribbon on your side panel, baste the cover material to your coutil piece and iron over the seam allowance along with the coutil.
For this corset, the panel was just slightly wider than the primary ribbon I am using, so I took some narrower black ribbon (7/8″ wide), folded it over the edge of the coutil, and stitched it down. When making your own ribbon corset, figure out a pleasing arrangement of ribbon and stitch it to the coutil panel.
Top-stitch the wide ribbon to the coutil panel along its edges.
Line up the prepared cover with the edge of the corset panel, perfectly lining up the coutil panels. Leaving the extra ribbon hanging off the top and bottom edges.
Top stitch the cover to the panel, being very careful to keep the coutil panels lined up.