1. To figure the width of your piping fabric strip, determine the width of your piping cord, add your seam allowance, and multiply by two. The cord in the example is 3⁄8" wide and the seam allowance is 1⁄4", so the strips are 1-1⁄4" wide. Cut enough length of strips to fit your project, and join them as you would binding strips to make one continuous piping fabric strip.
2. Fold piping fabric strip in half lengthwise; press and open. Insert piping cord inside strip against fold. Align raw edges and pin. Starting about 1" from short edge of strip, use a zipper foot to sew piping strip closed with a scant 1⁄4" seam allowance. Sew close to the cord but not through it (Photo 1). Stop sewing about 1" from remaining short end, leaving end of strip unsewn.
3. On right side of pillow top, align raw edge of piping strip with raw edges of pillow top, starting in the middle of one side and curving strip around corners; pin. Make small snips in piping strip seam allowance at corners (Photo 2). When short ends of piping strip meet, cut cord ends even with each other, fold a piping strip short edge in 1⁄4", and layer folded end of strip over the other (Photo 3).
4. Layer a hemmed pillow back piece atop pillow top, right sides together, with right-hand edges of both pieces aligned. Repeat with second hemmed pillow back piece, aligning left-hand edge of back piece with left-hand edge of pillow top. The two pillow back pieces should overlap.
5. Sew around outer edges through all layers. Turn right side out through overlapped pillow back pieces to make pillow cover.