How-to Sew: Flat Felled Seam
This video shows how to sew a flat felled seam. This type of seam is sturdy and durable and has no visible seam allowance. A flat felled seam is formed by placing one edge of fabric inside a folded edge of fabric with right sides together. Next, sew a straight stitch close to the opening. Then press the seam over to encase the raw edge. The flat felled seam is finished with a top stitch and an edge stitch.