The Flat Felled Seam Finish

How, where and why to sew a Flat Felled Seam finish. One way to hide your raw edges.

Looking again today at how to get a nice neat finish on the inside of your projects.  This isn't one technique that might immediately spring to mind and it's certainly not right for every project, but if you look closely you'll be surprised how often you might find it on your store-bought clothes.

How can we use the Flat Felled Seam?

The places you'll find the seam give clues to its features.  Looking down right now, I'm wearing a pair of board shorts and the side seams and the central seam running front to back between the legs are both flat-felled seams.  It's generally used on heavyweight fabrics such as jeans and on seams where extra strength is needed.

You can often also find it on children's wear where the seams might undergo a bit more stress as they rough and tumble. However, it does create a double line of stitching on the outside of the garment and is therefore not suitable for every application, but it can give a very professional looking finish if you can sew it accurately.  Let's have a go at creating a neat flat felled seam.

How to sew a flat felled seam

The flat felled seam can be sewn from either the inside or outside.  There's not much difference in techniques but which way you do it determines where the bulk of the seam will fall. For jeans, tote bags etc, you might have this on the outside, but for another garment sewing it might fall inside.

I'll be creating an ‘inside' flat felled seam in this example. Sew your seam as usual with your regular seam allowance.

How, where and why to sew a Flat Felled Seam finish. One way to hide your raw edges.

Press both seam allowances over to one side.

How, where and why to sew a Flat Felled Seam finish. One way to hide your raw edges.

Then trim down the bottom seam allowance to half its previous width.  Trimming accurately is important so if you have one, use a rotary cutter and mat rather than your scissors.


Fold the larger seam allowance up and over the smaller one, all the way nearly to the seam line stitched earlier.  Press this in place.  Again, accuracy is important, so fold and press carefully and use a seam gauge to get an even fold. Then fold the whole seam over on itself to the other side so that the raw edge is now hidden and press again.

How, where and why to sew a Flat Felled Seam finish. One way to hide your raw edges.

Return to the machine and edge stitch close to the free edge, trying to keep an even distance from the original seam line. If you have an edge stitching foot, or even a blind hem foot, this will help you stitch closely and evenly to that fold.

How, where and why to sew a Flat Felled Seam finish. One way to hide your raw edges.

Here's how it looks from the inside, and the outside.


How, where and why to sew a Flat Felled Seam finish. One way to hide your raw edges.

You may want to finish off from the outside by top stitching a third line of stitching just inside the original seam allowance for extra strength and decorative effect.

How, where and why to sew a Flat Felled Seam finish. One way to hide your raw edges.

Many flat-felled seams are finished with specialty threads for more prominent stitching lines or you can use decorative and metallic threads for a fun look too.  Of course, the iconic look of the yellow thread on denim is used in the seams on jeans everywhere.

Flat felled seaming for curves such as armholes is an advanced technique best left to the experts!

Next in the series – the French Seam.

Looking for previous seam finishes?   Part 1 – the Zig-Zag Seam Finish

If You'd Like To Support Our Site

If you want to help us continue to bring you a wide selection of free sewing patterns and projects, please consider buying us a coffee.  We'd really, really appreciate it.

Bookmark the permalink.

34 Responses to The Flat Felled Seam Finish

  1. Vernie Love says:

    I appreciate my emails from you. Very informative and interesting. Thank you.

  2. Pingback: How to use the overcasting stitches - So Sew Easy

  3. Daryl Kennedy says:

    Great tutorial, very easy to follow. I love all your tutorials. Thankyou.

  4. Pingback: The Turned Under Seam Finish - So Sew Easy

  5. Colleen says:

    Thank you. Trying to whip us an unlined linen jacket today and needed instruction. You saved me!!

  6. Linda Madden says:

    As always, a very helpful tutorial. Thank you for taking the time to make tutorials for us.

  7. Marsha Ludwig says:

    I love your story about the Hong Kong finish. Your written and instructions and visuals are concise and clear.
    I learned these seam finishes (including French seams) when I started sewing in the ’50s. My mother believed that a garment should look as finished on the inside as it does on the outside, and I still strive to achieve that goal.

    These seam finishes are aesthetically pleasing, and extend the life of the garment by protecting raw edges. More importantly, perhaps, they help hold its shape.

    • Mayra Cecilia says:

      Could not be put in better words, this is exactly why it is so much worth the time and effort to learn, master it and use it. No one will think you make the garment yourself when you use this type of finish.

  8. Kaz says:

    Than you! I recently made my first flat-felled seams after learning how from a good sewing book, and your tutorial has provided some excellent reinforcement. I like the idea of that third line of stitching.

  9. Janet Miller says:

    Very nice! And it looks nice as well. I learned a lot from this one too!

  10. A. Secoy says:

    This is great! As I mentioned with the French seam comment, will try this as well! Thank you for posting!

  11. Dottie says:

    Nicely done and explained. It can be tricky for inexperienced sewers without good pictures and instructions.

  12. Julie says:

    I love your tutorials, thank you so much! It seems to me that if you sewed the seam the other way round, you wouldn’t need to sew the third line of stitching for the outside, as the two lines of stitching would be visible on the outside. Would that be right? So, you would sew the seam on the outside? Does that make sense?

  13. Linda says:

    Why did you not put the folded seam on the right side? That is how I was taught to do it.

  14. Christina Block says:

    Love it. TY

  15. Eilea Princeton says:

    I wonder why anyone bothers with flat felled seams when french seams are so straight forward and finish the seams nicely.

    • Mayra at So Sew Easy says:

      Flat felled seams are best when working with think fabrics such as jeans and corduroy where french seams would make the sides too bulky.

    • Brian says:

      A French seam works well for drapes, but a flat seam would work better for a garment (like shirts) when the wearer prefers a planar finish.

  16. Krykit says:

    Wonderful! Thank you!

  17. Crystal Brudie says:

    Best flat felled seam instructions. They were exceptionally well written and very easy to comprehend. I feel well encouraged to try my hand at it now. Thank you kindly.

  18. Leigh-Ann says:

    Very clear instructions. Just in time too! Getting ready to tackle my first pair of jeans. That is the side seam I would like to use. Thank you very much!

  19. Olivia Morrissette says:

    Thank you, Mayra! I live way up in the woods where everything is a ways to get to (like sewing classes), so I LOVE these tutorials!

    • Mayra at So Sew Easy says:

      You are most welcome Olivia, Sound like paradise to me. Are you able to get things delivered to you or do you have to make a huge list to be able to make a few projects?

  20. ronnie jenzen says:

    Hello. Great tutorial and thank you. I have a question though. Is it possible to sew a single seam down a sleeve like a sweatshirt ( but running on top ) using a flat felled seam ? I’m under the impression it can’t unless done by hand. It’s for a kayaking dry top, waterproof material and I plan of Shoe Goo’ing the fold of the seam if it can be done. Thank you in advance.

    • Mayra at So Sew Easy says:

      Hi Ronnie, my concern would be the width of the sleeve to be able to finish the sleeve using a machine. Can you send me a photo I will be able to help you better if I can see.

  21. Marlette Louisin says:

    I think doing the flat fell seam on the outside is more comfortable for clothing as you don’t have the folded edge rubbing against your skin.
    Thanks for the great instructions.. It’s so important for beginner sewers or sewers who may not have done a certain technique to have clear instructions like yours!

    • Brian says:

      These instructions were very easy to understand. Of course now I’m curious to see what type of machine is used to do the hem-to-cuff felled seam used on men’s shirts.

  22. Maureen McQ says:

    Best flat felled seam creation instructions, ever. Great job. You have a talent for writing clearly and concisely, without leaving potentially important steps out.

  23. Pingback: Titanic Panic! – Making a Princess Slip or Petticoat | Tea in a Teacup

  24. Jeewaka says:

    Nice idiaa!great..

  25. Kristina & Millie says:

    great tutorial! very easy to understand!

  26. Joaniez says:

    great tutorial,thank you!

  27. katiasafia says:

    thank you for evry thing

Leave a Reply

Your email address will not be published. Required fields are marked *