How to Sew a Flat Felled Seam – (Full Guide)

Last Updated on July 6, 2023

Learn How to Sew a Flat Felled Seam: A flat felled seam is a strong and durable seam commonly used in denim and other heavy fabrics. It not only provides strength but also gives a clean and finished look to your sewing projects.

How to Sew a Flat Felled Seam
Image Source: Youtube (Howcast), Canva

How to Sew a Flat Felled Seam?

This strong and durable seam is commonly used in sewing projects like jeans, shirts, and bags. It encases the raw edges of the fabric, providing a neat and finished look.

Here’s a simple guide on how to sew a flat, felled seam:

Materials needed

Step 1: Marking Wrong Sides

Marking Wrong Sides
Image Source: Youtube (Howcast)

Before starting, identify the wrong sides of the fabric pieces you’ll be sewing together. Mark them with a small pencil or clip to avoid confusion during the process.

Step 2: Sewing Wrong Sides Together

Sewing Wrong Sides Together
Image Source: Youtube (Howcast)

Place the fabric pieces together, aligning the wrong sides. Start sewing along the seam line using a 5/8-inch seam allowance. Guide the fabric along the 5/8-inch marking on your seam guide and sew a straight stitch. Use a stitch length of 2.5 millimeters. Sew all the way down to the bottom of the seam.

Step 3: Finger Press Seam

Finger Press Seam
Image Source: Youtube (Howcast)

After sewing, finger press the seam open to make it lie flatter. Gently press along the seam with your fingers to flatten it.

Step 4: Trim One Side of the Seam Allowance

Trim One Side of the Seam Allowance
Image Source: Youtube (Howcast)

To create the flat felled effect, trim down one side of the seam allowance. Leave approximately between 1/8 and 1/4 of an inch of the trimmed seam allowance.

Step 5: Hide Edges

Hide Edges
Image Source: Youtube (Howcast)

Take the larger seam allowance and fold it under, encasing the trimmed side of the seam allowance. Fold the entire seam allowance over to hide all the raw edges. Pin the folded seam in place to secure it.

Step 6: Pin Seam

Pin Seam
Image Source: Youtube (Howcast)

Continue pinning the folded seam in place along the length of the seam. Use a seam guide or ruler to ensure the fold is even and straight if desired.

Step 7: Stitch Close to Fold

Stitch Close to Fold
Image Source: Youtube (Howcast)

With the pinned seam in place, go to the sewing machine. Stitch close to the folded edge, securing the seam. Start sewing from the top and stitching down to the bottom, removing the pins as you sew.

Step 8: Edge Stitch

How to Sew a Flat Felled Seam - Edge Stitch
Image Source: Youtube (Howcast)

To create a neat edge stitch, lower the sewing machine’s presser foot and stitch close to the folded edge. You can use the edge of the inside of the presser foot or any reference guides on your presser foot to help guide your stitching.

Step 9: Finishing Touches

How to Sew a Flat Felled Seam - Finishing Touches
Image Source: Youtube (Howcast)

Once you have stitched the entire length of the seam, your flat felled seam is complete. Take a moment to admire your work! The side with the enclosed seam will be the right, while the side with the visible fold will be the wrong. However, you can choose to use the seam look on the right side if you prefer.


The side with the visible folded edge is the right side, while the opposite side is the wrong side. Sewing a flat felled seam requires practice to achieve precision and consistency. Experiment with scrap fabric pieces before working on your final project to gain confidence in this sewing technique.

Ask any Question Here!