Comparison
Overlock stitch vs zigzag for finishing seams
Published
Note: This page contains affiliate links. If you buy through them we may earn a commission at no extra cost to you. Learn more
In short
A zigzag or overcast stitch on a sewing machine stops most fabrics fraying and is perfectly adequate for cottons, linens and many dressmaking projects. A true overlocked edge from an overlocker is faster, trims as it sews and gives a neater, stretchier finish, which matters most on knits, loose weaves and garments you wash often.
Janome
Janome 9300DX: 1,500 spm with rolled hemming
Check price on AmazonAffiliate linkJanome
Janome 360DC: 60 stitches, 7 mm zigzag
Check price on AmazonAffiliate link
- Janome 9300DX: 1,500 spm with rolled hemming
- Weight
- 8 kg
Check price on AmazonAffiliate link - Janome 360DC: 60 stitches, 7 mm zigzag
- Weight
- 5.5 kg
Check price on AmazonAffiliate link
| Product | Weight | Link |
|---|---|---|
| Janome 9300DX: 1,500 spm with rolled hemming | 8 kg | Check price on AmazonAffiliate link |
| Janome 360DC: 60 stitches, 7 mm zigzag | 5.5 kg | Check price on AmazonAffiliate link |
Details as stated in the Amazon listing or by the manufacturer. See the current price on Amazon.
Our verdict
A sewing machine such as the Janome 360DC handles seam finishing well on cottons and firm wovens with its zigzag and overcast stitches. Choose an overlocker like the Janome 9300DX if you sew lots of knits, linen or fraying fabrics and want faster, ready to wear seams.
Raw seam allowances fray, and the inside of a garment shows it. You can neaten them on any modern sewing machine with a zigzag or overcast stitch, or with an overlocker that sews, trims and wraps the edge in one go. Both work. The right choice depends on your fabric, how often you sew and how tidy you want the inside to look. This guide compares the stitches, then goes fabric by fabric.
Zigzag, overcast and overlock: the three finishes
A zigzag stitch swings the needle side to side. Sewn just inside the raw edge of the seam allowance, it holds the threads in place so they cannot unravel far. It is available on almost every machine, and stitch width and length are adjustable.
An overcast stitch on a sewing machine is a built in pattern designed to wrap over the cut edge, usually sewn with an overcasting or overedge foot that has a small bar or guide to stop the fabric tunnelling. It imitates an overlocker more closely than a plain zigzag. Names vary: some makers call it overedge or overlock stitch, though it is still formed with a needle and bobbin.
A true overlock stitch comes from an overlocker. Needle threads sew the seam, two looper threads wrap the edge, and a knife trims the allowance just ahead. The finish is dense, stretchy and very fast to sew. Our sewing machine vs overlocker guide explains the machine itself in more detail.
Overlocker and sewing machine side by side
The Janome 9300DX is a 3 and 4 thread overlocker and the Janome 360DC is a computerised sewing machine with zigzag and decorative stitches. The table lists only what the product listings state.
| Feature | Janome 9300DX | Janome 360DC |
|---|---|---|
| Machine type | Overlocker | Computerised sewing machine |
| Stitch options listed | 3 or 4 thread, rolled hemming | 60 utility and decorative stitches including 6 buttonholes |
| Width or length | Maximum stitch length 5 mm | 7 mm zigzag width |
| Feed | Differential feed | 7 segment feed dog, adjustable presser foot pressure |
| Maximum speed | Approx. 1,500 stitches per minute | Not stated (speed control with infinitely variable adjustment) |
| Weight | 8 kg | 5.5 kg |
| Dimensions (D x W x H) | 26 x 28 x 28 cm | 16 x 40 x 28.5 cm |
Which finish suits which fabric
Fabric behaviour matters more than the machine. Firm wovens accept a zigzag happily. Loose weaves and slippery fabrics fray quickly, and a zigzag can pull them into a ridge. Knits do not fray much at all, but their seams must stretch, which is where the overlock stitch shines.
| Fabric | Zigzag or overcast | Overlock |
|---|---|---|
| Quilting cotton, poplin, shirting | Works well, medium width zigzag | Very neat, quicker on long seams |
| Linen and loose weaves | Use an overcast foot to stop tunnelling | Best option for fraying edges |
| Denim and canvas | Works, but bulky seams may need trimming first | Neat on mid weights; check the overlocker copes with the thickness |
| Jersey and stretch knits | Use a narrow zigzag or stretch overcast | Ideal, seams stretch with the fabric |
| Chiffon and fine silks | Can chew or pucker; French seams often better | 3 thread narrow or rolled edge suits most |
| Fleece and sweatshirting | Workable, edges do not fray much | Fast and tidy, reduces bulk |
How to get a clean zigzag or overcast finish
If you only have a sewing machine, a few habits make the zigzag finish look far more professional. Stitch settings differ between models, so treat the numbers below as a starting point and test on a scrap of the same fabric.
- 1
Sew and press the seam, then trim the allowance evenly if needed.
- 2
Select a zigzag of around medium width and a shortish length, or the overcast stitch shown on your machine's stitch chart.
- 3
Fit the overcast or overedge foot if your machine has one, so the guide sits against the cut edge.
- 4
Sew so that the right swing of the needle just clears the edge of the fabric.
- 5
Press again; if the edge rolls into a ridge, reduce the width or loosen the upper tension slightly.
Note:Switch off and unplug the machine before changing the presser foot or needle. For motor, wiring or timing faults, use a qualified sewing machine engineer.
When an overlocker is worth it
An overlocker earns its place when you sew lots of knits, when you work with fraying fabrics like linen, or when you simply want a ready to wear finish and faster sewing. Trimming and neatening in one pass saves time on every seam, and differential feed helps avoid wavy knit seams. Our differential feed explainer shows how to set it.
If you sew mainly firm cottons, quilt, or make occasional garments, a sewing machine with good overcast stitches is often all you need. Look at our best sewing machines for dressmaking for models with useful edge finishing stitches, and our overlocker threading guide if you decide to make the jump.
Frequently asked questions
Is an overcast stitch the same as an overlock stitch? Not quite. An overcast stitch on a sewing machine imitates an overlocked edge using a needle and bobbin. A true overlock stitch uses loopers and usually trims the edge with a knife, which gives a denser, stretchier finish.
Can I use zigzag instead of an overlocker on jersey? Yes. A narrow zigzag or stretch overcast stitch with a ballpoint or stretch needle works on most jersey. Our guide on how to sew stretch fabric covers the settings.
Do I need to finish seams on knit fabric? Many knits barely fray, so finishing is partly about appearance and comfort. An overlocked seam is flatter and stretches with the fabric, which is why ready to wear knitwear uses it.
Why does my zigzag edge curl into a ridge? The stitch is usually too wide for the fabric or the tension is too tight. Reduce the width, use an overcast foot and test on a scrap; check your manual for tension guidance on your model.
What you need
- Check price on AmazonAffiliate link
Janome 8004D: pre-threaded, colour coded guides
- Check price on AmazonAffiliate link
Janome 5270QDC: 270 stitches, 12 buttonholes, knee lifter
- Check price on AmazonAffiliate link
Janome JW8100: 100 stitches, 7 buttonhole styles