Take a look at your jeans or at a men’s dress shirt, and you’ll spot flat fell seams. On the outside of the garment there is a pair of stitch lines, and on the inside of the garment, it’s all clean and tidy without raw seam edges. Ever wonder how they did that? Well here you go! Let’s learn how to sew a flat fell seam, so you can try it on your next project.
How to sew a flat seam
Step 1: Pin the fabric of the seam together, wrong sides facing.
Step 2: Sew the seam with the wrong sides facing at the project’s allotted seam allowance. This example is being sewn at 5/8".
Step 3: Press the seam open on both sides of the fabric. Be sure to set your iron for the type of fabric being used.
Step 4: Trim one side of the seam allowance down to 1/4". Do not trim the other side.
Step 5: Press the untrimmed seam allowance over the seam and on top of the trimmed side.
Step 6: Fold the pressed side under, tucking the raw edge into the fold.
Step 7: Press the fold, making sure that the raw edge is fully tucked under and that the flap left is the same width along the seam.
Step 8: Line up your fabric in your machine so the stitching is close to the fold.
Step 9: Stitch along the edge of the fold, trapping all the raw edges inside.