Technique of Mock Flat-Felled Seam

A smooth, pleasant seam, the flat felled seam is ideal for medium-weight materials and apparel that demands optimal durability. If you have an active toddler running around, this seam makes sportswear and casual wear look very professional. It is also durable and ideal for overalls and rompers. Because the majority of the seam is on the outside, they are comfy.

Flat-felled seams are frequently used on heavy-weight fabrics, such as denim and canvas, to strengthen clothing. Look at your jeans right now. It seems to be a standard flat-felled seam when viewed from the right side. If you look inside, you’ll see that it most likely looks more like a mock flat than a typical flat. The straightforward explanation for this is that creating a faux flat-felled seam is quicker when sewing in production. Additionally, it results in a seam that is a little bit less thick, which is perfect for particularly heavy materials like denim.

What is a Flat-Felled Seam?

A flat felled seam is a straightforward seam created to provide a beautiful and incredibly durable seam, as well as to envelop raw edges to prevent them from fraying. The image below shows the interior of the item, which has a clean finish with no exposed rough edges or finishes. This makes it a wonderful seam for those who dislike serged seams, especially children. These seams combine the functions of a seam and a seam finish. If you don’t have a serger, this could be a great substitute for making simple flat open seams.

What is a Mock Flat-Felled Seam?

A mock flat-felled seam is used for thicker textiles such as denim and canvas. You’ll frequently find this seam on the inside of your pants and denim jackets. Due to the lack of pressing required for the seam allowance, it can be finished more quickly and with less volume. The best seam allowances for a mock flat felled seam are at least half an inch (12 mm) broad.

When to Use a Mock Felled Seam?

Denim and thick textiles are perfect for the mock flat-felled seam, but heavier fabric could be too bulky. Many of the seams on your denim jacket, pants, and shirts have been ripped. Because the raw edges are enclosed and prevented from fraying by flat-felled seams, linen is a wonderful material for them. If you’re a newbie, you should stick to straight seams because it is harder to sew around curves.

How to Sew Mock Flat Felled Seam?

It includes

Step 1: Complete one side

Finish the fabric’s seam allowance on one side. Although a serger is ideal, a straightforward zig-zag stitch will work if you only have a standard sewing machine. If you don’t want your piece of cloth to get smaller, make sure the serger knife only cuts the bare minimum seam allowance.

Step 2: Sew the seam

Using a standard sewing machine, sew the seam with the right sides together and the desired seam allowance.

Step 3: Trimming

Reduce the unfinished seam allowance to a width of one-fourth inch (6 mm).

Step 4: Press to the side

Over the seam allowance that was trimmed, press the completed seam allowance. Make sure the seam is open and smooth on the correct side and that there are no creases.

Step 5: Stitching

Next to the final edge, stitch the seam into place. You will be stitching about three-eighths of an inch (1 cm) from the seam if your seam allowance was half an inch (12 mm).

Turn your work to the correct side of the cloth to complete it, then give it one last press to flatten the seam.


To sum up, a mock flat felled seam is a quicker, flatter, and more compact variation on a flat felled seam. For a mock version, you would sew the two pieces together after finishing just one edge of the seam allowance. The stitched-down finished seam allowance in a mock flat seam conceals the unfinished seam allowance. The mock flat-fell seam makes a seam that is completely finished and identical on the front and back. This is helpful for applications or transparent textiles where the front and back may be seen. As far as I can tell, it’s not an actual seam; rather, it’s the result of my failure to follow clear instructions for a flat fall.

Updated on: 14-Feb-2023


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