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Creating Professional-Looking Flat-Felled Shirt Seams

Get smoother, neater results with this unconventional method.

The flat-felled seam is an elegant seam finish, and you can learn to sew it masterfully to create professional-looking garments, especially shirts. Flat-felled seams are commonly used for the shirt armhole seam and the shirt sleeve and side seams.

When I first started making shirts, I used the method I learned from sewing books and commercial shirt patterns: Flat-felled seams are sewn with a 5/8-inch-wide seam allowance; one side is trimmed roughly in half; the wider side is folded over the narrower; and finally, the folded seam—with the wider side encasing the narrower—is topstitched along its outer edge, usually from the wrong side of the shirt. One of the big challenges to this method is that, given the curve of the armhole, trimming and folding is painstaking, and the folded seam allowances are difficult to anchor neatly before sewing. The result, particularly with delicate fabrics like fine cotton shirting or loosely woven fabrics prone to raveling, is often lumpy and uneven.

Alternative flat-felled seam

I learned an alternative method in a men’s shirtmaking class at New York’s Fashion Institute of Technology (FIT) taught by Mark-Evan Blackman, former chair of FIT’s Menswear Design department. Professor Blackman’s process is easier, requires less painstaking trimming, and yields a superior result. Below, I describe the steps involved. For the samples shown, I worked with 5/8-inch-wide seam allowances, just as one would while sewing a commercial shirt pattern.

Dress shirt with flat-felled seams
This 100 percent cotton men’s dress shirt with flat-felled seams is made from William Morris “Anemone” print yardage, which was a gift from a friend.

Note: The method I describe requires the sleeve be attached “in the flat,” i.e., before the side and sleeve seams are sewn.

Finish the sleeve’s armhole edge

1. Assemble the shirt body, which includes…

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Previous: Princess Seams and Other Treacherous Curves Next: Learn the Four Fastest Flat-Fell Seams


  1. AnnaOPR | | #1

    I practiced fell stitches with muslin; straight and curved seams. This technique looks better when compared with the traditional method or variations on the fell seam, even on curved seams. Thank you.

    1. User avater
      Peter_Lappin | | #9

      So glad you like it!

  2. User avater
    cozzmo | | #2

    Great article! well written and understandable. I am not a beginner sewist however I 've not sewn many men's shirts. The nice flat felled seams I have admired now seem possible for me to tackle. Thanks again -

  3. user-7552342 | | #3

    WOW! Great article. I appreciate your clarity of instruction. I will have no trouble following this improved technique. Write more articles please!!

  4. User avater
    sunnylutz | | #4

    Excellent article and very thorough. Just when I thought you were about to lose me, you provided a very detailed photo to help. Can't wait to try this on the shirt I'm sewing for my husband!

  5. SherrieLA | | #5

    Wow! Zow! I’m loving this method. Thank you for such explicit instructions.

  6. onceover | | #6

    I love your instructions and wonder how it works on bulky jeans. Maybe instructions coming soon? I've sewn for 50 years or so but still have trouble with collar stands meeting shirts at the front, also cuffs as I follow commercial pattern instructions and thus have trouble. As you have perfected your instructional talent, maybe help is in the future or maybe I missed it. Thank you kindly for your expertise!

  7. User avater
    Deleted | | #7


  8. User avater
    Deleted | | #8


  9. Rusty_Sewist | | #10

    I just did this and it is beautiful and made fitting the sleeve to the shirt so much easier.

  10. user-7819900 | | #11

    great tutorial, thank you so much! I will be implementing this technique today .

  11. miamorningpurcell | | #12

    THANK YOU so much!!

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