Pattern Hack Fairy



Faux Flat Felled Seam for Denim Crotch Curves


A true flat felled seam in curvy areas can be a challenge, even when you have a powerful machine and specialty feet. But what if all you have is a basic home machine and a regular pressure foot?

Here is my “faux” flat felled technique that is both strong and easy to do!

I am demonstrating with duck canvas and black thread so you can better see what I am doing.

You only need a 1/2″ seam allowance. This is because this seam only really overlaps itself about 1/8th of an inch and curls under another 1/8th of an inch. I really think a 3/8″ seaming is best for a crotch curve, but you can still do a 1/2″… I just think it takes more time to master and get to lay right without crimping/crumpling.



Here I have cut a back crotch shape. I put very tiny little “nip” notches into the curves, but you can also just mark the fabric at regular intervals so you are sure to match everything up in your sewing.

Next, I am going to butt the two edges together and you may even overlap them slightly if you like.

Now I’m going to do a zig-zag stitch to secure it down.  I’m using about a 5mm wide stitch.


Next, I fold the seam in half, then shift the zig-zag inward about 1/4″ with my fingers.  Then I will stitch a straight stitch seam at 1/2″.


Now we flip that seam allowance over to conceal the zig-zag stitch.

The seam allowance with the zig-zag stitch ends up on the inside of the garment.

We will now to the exposed top stitching on the outside, starting with the edge stitch.


Next, let’s do the second stitch.  It is helpful to pick a spot on your pressure foot and select a needle position that helps you keep an even stitch placement parallel to the first stitch.  Of course, there are other specialty feet, and the option of using a twin needle… but this example is based on having only a basic machine and regular pressure foot.


The inside of your seam will have an extra stitch, which is a little different looking than a true flat felled seam.  You can use wash-away thread, or you can just use a matching thread and it will not be as noticeable.  Likely your double top stitching will be in a contrast color.

(Inside view)

Categories:   Sewing Techniques