Joining the Ribbon Sections to the Panels
Draw your seam allowance on the coutil panel. Match the center marks, and line up the stitches on the ribbon panel with the line on the coutil. Pin to the edges, lining up the stitching with the seam allowance line.
If you are using cover fabric on the back panel, sew it into this seam between the coutil and the ribbons.
Carefully pin the seams together, using as many pins as necessary to ensure that the seams stay aligned while sewing.
Sew the seam directly on top of the stitches that are holding together the ribbons.
Fold over the coutil so the seam allowance and the loose ends of the ribbon go across the body of the back panel. Iron it over in a tight fold against the seam. Top-stitch to secure. Try to keep the coutil panel as straight as possible, and allow the ribbon ends to flare out. Adjust the ribbons as needed so they lay smoothly across the coutil. If they need to be cut to lay flat, cut straight down the length of the ribbon until it will lay flat (this was done on the side panel, and can be seen later on).
Keeping the coutil as straight as possible, quilt down the ribbons across the width of the panel. Stop at the seam allowance for the other side of the panel. The quilting lines will not be visible on the finished garment, so they do not have to be absolutely even or precise.
If you are using cover fabric on the back panel, hold it out of the way while quilting the ribbons to the coutil. You do not want the cover material quilted.
Trim any excess ribbon on the far side of the panel. Trim along the top and bottom edges away from the seam with the ribbon panel. In this corset the line of the ribbon panel is continued by the coutil panel, so the edge of the ribbon is naturally flush with the edge for about a half inch. If the ribbon immediately goes beyond the edge of the coutil, fold it over instead. Trimming the ribbon right up to the seam will create a weak place where the threads of the ribbon may pull free from your garment.
Stitch down the edges of the ribbons. These stitches will prevent the boning from trying to go between the ribbons later on. If you plan to use boning tape, these stitches are not necessary.
Next you will want to stitch the other side of your ribbon panel to the side coutil panel.
As you add each panel, you want to make absolutely certain it is oriented to match the part of the corset that is already assembled. Pin carefully to match the seam mark and the seam stitch, and double-check before sewing them together. Pay very close attention to your front and back sides, up and down orientation, and waistline marks. Use the extra marks to make sure you are lining everything up properly. It should all match.
Use the same procedure as shown above when attaching each new panel.
If the curve at the waist is too great to allow for the center ribbon strip to lay down flat across the side panel, cut it straight down the middle. Do not cut all the way to the seam. Stop about 1/8″-1/4″ from the seam. If you go all the way to the seam, some of the ribbon may pull free and create an unsightly, frayed, weak area in the corset. Depending upon the curves of your corset and the flexibility of your ribbon, you may need to do this to many of your ribbons. The important part is to get them to lay flat on an un-distorted side panel.
Quilt down the ribbon just like before, taking care to keep the coutil panel straight and adjust the ribbons as needed so they will lay flat. Fold the ribbon over the top edge of the coutil panel instead of trimming it. If you trim it, you run the risk of having the ribbon pull free from the side panel at the top and bottom of the corset. Trim at the seam allowance on the opposite side of the coutil panel.
Lay out the assembled portion of the corset and carefully orient it to match the next ribbon panel.
NOTE: Do not automatically trim the loose ribbon at the top and bottom of each panel. Most of the time you will want to fold it over, otherwise the edge of the ribbon will be too short to hold into the coutil. By folding it over, it will stay put.