S916 Cap with 3-thread flatlock stitch
i-Tips 3-thread flatlock stitch
Using the example of model S916, Cap, from Inspiration Special 2013
Basically, there are two ways to sew a flatlock seam. For purely decorative purposes, the thread chain is only half-filled; if the seam is to be subjected to a lot of stress, the edge is cut off with the knife as usual, i.e. the chain is filled completely.
You’ll find the settings for a 3-thread flatlock stitch, left needle, in your user manual. Depending on the thickness of the material and the thread used, readjustments may be necessary. For the thick sweatshirt fabric and the Madeira Cotona overlocking thread, we’ve set the thread tension of the needle, upper looper with the Cotona overlocking thread, and lower looper to 2.5, 0 and 9, respectively. Stitch length: 3 – 3.5. The settings work for sewing a flatlocked seam using either of the above methods.
Decorative flatlock seam
This type of flatlock seam can be sewn both on fabric folds and on open edges. The fabrics used must be non-fraying – jersey and sweatshirt fabrics are ideal. The knife is turned off. When cutting out, the seam allowance is either left off, or can be reduced to 2 mm.
Place two sections wrong sides together at a time. As you sew, the fabric edges are guided along the slot in the sole of the presser foot, so the thread chain is filled only halfway.
On the front, the thicker decorative thread lies loosely around the corner; on the back, the needle thread extends beyond the edge of the fabric.
After sewing, pull fabric apart. It should now lie flat underneath the decorative stitch. Looking at the back, you’ll now see cross stitches, and the fabric edges lie end-to-end.
If the beginning and end meet up, cut off the threads at the beginning and oversew the beginning with a few stitches. ‘Sew out’ as usual and cut off thread. Unpick the final stitches and pull in with a thick needle.
Strong flatlock seam
If the seams are to be subjected to greater stress, the knife remains on as you sew the flatlock. Note that fabrics that fray more readily are not suitable for this technique either.
As usual, include a seam allowance of just under 1 cm when cutting out. After the fabric is pulled apart, one layer lies on top of the other, and very often a fabric edge also curls up. This is easily corrected with a blunt hand-sewing needle. Slide the needle under the stitches and adjust the fabric there. This will also make the seam as flat as possible.