Sewing Activewear Tutorials / Tutorials / Velo Knit Cap Sew-Along

Sewing Machine Mock Flat-Lock Seam Tutorial

For the Velo Knit Cap sewing pattern, you can create a very neat looking mock flat-lock seam on a regular sewing machine. This type of seam keeps the bulk to a minimum and is pretty much chafe-free too. So it’s an excellent choice when you want to level up the look on knit garments, but only have access to a sewing machine.

Since it requires pressing the seam allowance open the method works best on fairly stable knits with up to moderate stretch. In this example, I used a felted wool knit, but fleece, sweatshirt fabrics, french terry, velour and double-knits work just as well for this method.

1. Sew together the cap seams with a narrow zigzag stitch

The seam allowance should be 1 cm (3/8″) or less. I prefer using a 6 mm (1/4″) allowance when sewing these type of seams. A narrow zigzag is a better choice than a straight stitch since the zigzag has stretch and won’t pop.

2. Press the seam allowances apart

This is an important step and one of the reasons more stable knits are best suited for this method. If you are working with very slippery, thin synthetic knits, pressing the seam allowance apart won’t be an easy task.

3. Pick a stitch

Pick a decorative sewing machine stitch that has some stretch. Most modern sewing machines have a plethora of stitches that will work for this, such as overlock stitches, honeycomb stitches and many more. But always do a test run before sewing your actual make, to make sure the seam will stitch easily over all the layers and has enough stretch.

4. Stitch the seam

Stitch over the cap seam allowances from the right side. The seam ditch should be in the middle of the presser foot.

The mock flat-lock seam as seen on the right side

I really like how pretty and neat this type of stitching looks.

The seam on the reverse side

As you can see the seam allowance lies nice and flat. And you don’t really need a wide seam allowance, even the 6 mm (1/4″) has some extra room on the sides.

The finished Velo Knit Cap, sewn together using only a sewing machine. This style is one of my favourite of all the samples I did for the Velo sewing pattern!

My daughter Stella wearing the mock flat-lock version of the Velo Knit Cap. Love how it looks on her <3


  • […] stitch or use a regular zigzag stitch, and sew over the seam from the right side. Check out this step-by-step photo tutorial on exactly how to sew this stitch on your sewing […]

  • Camie
    May 23, 2023 at 4:12 am

    Can I know the sewing machine name please?

    • Shirley Bayless
      December 29, 2023 at 12:17 am

      It looks like a Bernina 1130.

    • Richard Comeau
      February 22, 2024 at 6:25 pm

      Bernina 1230


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