Thursday Tip // Seam finishes

So, you’ve just finished sewing your first seam and you might be wondering, now what?!

The last thing you want is for your garment to start unraveling at the seams so the next important sewing step is to finish the raw edges of the fabric. If your garment is unlined and has exposed seams that will come in contact with your body or are exposed when washing, you will need to finish those seams in some way to protect them from fraying and coming apart.

In this week’s tip we discuss some beginner friendly seam finishing techniques that don’t involve a lot of extra steps or fancy tools.

All woven fabrics, by nature of the weave, will begin to fray when cut if the edges are left raw. Knit fabrics don’t tend to fray so seam finishes for knits are typically optional depending on the garment or the specific type of fabric. The seam finishes we suggest here are generally for woven fabrics only.

5 types of seam finishes:

Zig zag stitch (through both layers)

The zig zag seam finish is very common and is a quick way to finish a seam. After you have constructed the seam with a straight stitch at the correct seam allowance, zig zag inside the seam allowance (between the stitching line and the raw edge of the fabric). The raw edge can then be trimmed down a little closer to the zig zag stitching line.

Pros: Fairly quick and catches both layers of the seam in one pass

Cons: A little bulkier because the seam can only be pressed to one side, not open.

Zig zag stitch (through one layer, prior to sewing)

Another option for the zig zag stitch is to zig zag the raw edge, within the seam allowance of each pattern piece before constructing any seams. This allows you to finish the raw edges separately and therefore they can be pressed open easily. This would be especially useful for fabrics that tend to fray very quickly (eg. linen) as it secures those edges before too much unravelling can happen with handling the fabric.

Pros: allows the seam to be pressed open and good for hard to reach seams that are trickier to trim down (eg. armholes, curved seams)

Cons: takes more time to zig zag each edge separately

Pinked edge (using pinking shears)

Another quick option to finish your raw edges is to use pinking shears. These shears have a zig zag blade and cut the fabric at small angles to prevent fraying. Pinking shears are readily available and are a very common way to quickly finish a raw edge that can be pressed open or to one side.

Pros: quick to cut through both layers and gives a clean finished look to the edges

Cons: doesn’t work well for loose weave fabrics, best for tight weave cotton or canvas

Turn under and stitch method

This method results in a very clean finish. After sewing the seam with a straight stitch you then press the seam open so you can access each side of the seam allowance seperately. Next, on the wrong side of the fabric, turn each side of the seam allowance under (toward the stitching line) and press at ⅛” to ¼”. Then sew a straight stitch along each of these folds, only catching the seam allowance in the stitching line. Press open again and no raw edges should be visible.

Pros: Stitching is quicker than a zig zag and uses less thread, can be pressed open

Cons: Pressing can be a little fiddly and long seams would take longer.

Overcast stitch

If your machine comes with multiple stitch options you may find one similar to this overcast stitch pictured below. It stitches both a straight stitch line at the correct seam allowance and zig zags toward the raw edge simultaneously. The raw edge of fabric can then be trimmed down closer to the zig zag stitching.

Pros: constructs and finishes the seam in one pass

Cons: slower and harder to unpick if you make a mistake or need to adjust something later.

Let us know if you have any questions in the comments or feel free to send us an email! We love to hear from you. Cheers!