If you are sewing two panels together and then pressing the seam allowance open , when do you serge the edges? Do you serge that end before stitching the two panels together, or do you stitch then serge afterwords. I imagine doing it after has the benefit of getting a smaller open seam, but is much harder to work with under the machine.
If you want to press open the seams, such as the 1st picture on the left, it’s easier to serge all of the edges before sewing the seams.
The 1st pic shows this order: cut, serge, sew, press open.
The second pic with the seem serged together, is typically serged after the seem is sewn. Though, it is possible to serge the seem and then straight stitch after.
I have practiced all options for various reasons with different types of fabrics. When serged separately, alterations can be made later. “Take it in” or “let it out”
When serged them together, that’s it. 😁
So, for woven fabrics that you want to make alterations to in the future, serge all your edges after cutting, make your pattern markings, then sew and press seems open as you progress through the garment.
It depends on the fabric, the properties of the finished piece and the person sewing the piece.
It's best to serge each edge independently if:
- The fabric is slippery, frays extremely quickly or is otherwise hard to handle. Serging each piece gives you more room for errors and to undo seams without undoing the serging.
- The garment is supposed to be worn by different people or by a person with a rapidly changing body (like children or pregnant people). Leaving a big seam allowance gives you the opportunity to adapt the garment to different body shapes.
- The fabric is very thick and you want to avoid bulky seams. Pressing the seam open looks neater in thick fabrics than pressing the seams to one side.
It's best to serge both pieces together if:
- You want to finish quickly and save resources. Serging uses up A Lot of thread.
- There's little risk of you ever needing to undo the seams.
It's best to serge the edges after sewing the seams if:
- You cut with big seam allowances but don't want to leave all that extra fabric in the finished garment. For example if your pattern doesn't fit you 100% and you want to make little alterations before cutting the seam allowance back.
It's best to serge the edges before sewing the seams if:
- The fabric frays a lot. You'll want to get that dealt with as soon as possible.
- The finished piece will be very big or heavy and difficult to get under the machine after sewing the seams.
Some situations dictate one order or another, but in most cases it's up to the preference of the person doing the sewing.