To make the piping trim, bias cut (45 degree angle to the selvedge) strips of your chosen fabric and fold around the raw cording with right side out and raw edges lined up. Experiment first with small pieces to find the right width for the strip so that it finishes with the correct seam allowance (we are using ½”) once sewed. Once you determine what width they need to be and cut several, seam them together so you have a continuous piece for your entire length of cording. Use a zipper foot to allow you to stitch as close to the cord as possible without stitching through it. The fabric should be tight around the cord now. By the way, it seems to always take more yardage of piping than you think, so measure well and then add to that for fudge factor.
To sandwich the cording between the seams, I like to hand or machine baste the cording onto one cushion panel first, then sew on the other side with right sides together. It’s an extra step, but it keeps the piping even. Be sure to start and stop the piping at an inconspicuous part of the cushion, like the bottom and allow some excess to overlap and extend off the edge (to be trimmed off later). We’ve done a two-part envelope closure on one side, so the pillow can be flipped right side out and stuffed.
Stay tuned for the final result...