Snap… snap-snap-snap! There go your stitches if you’ve sewn your jersey top with a regular straight stitch on your sewing machine. 😦 Surely, there must be a better way!
Yes, there are in fact several. In this post I’m investigating which stitches stretch with the jersey and which don’t, using regular sewing thread, not lycra which they often use in industry. That’s cheating! 😉
- The 3- and 4-thread overlock stitch
- The flatlock and the coverstitch
- The long bobbin straight stitch
- Narrow zig-zag
- Stitched zig-zag and feather
- Back-and-forth stretch stitch
- Single thread chain stitch
How far do you want to stretch?
This is the root of it all. How stretchy is your jersey in the direction of the seam? Well, stretch it and see.
The thing is, most jersey, or knitted material, does not stretch in equal measure in all directions. There are many reasons for that, it’s the nature of it (ask the knitters). The question to ask yourself is how stretchy your seams need to be, or have to be, or may be even should not be! Just think of the shoulder seam – do you really want that to stretch beyond measure? No, you usually want it to follow the pattern and to keep shape, so you reinforce it with a non-stretch twill tape. This seam can be done on your regular sewing machine as it is basically the same as any woven cloth!
Shoulder seams aside, most jersey seams should really be stretchy in the same measure as the jersey itself. Even if you don’t normally walk around vigorously pulling your T-shirt in all directions, you still do it when putting it on or taking it off, and this is usually when the stitches snap. So there is every reason to use a stretchy stitch on jersey.
The 3- and 4-thread overlock stitch
These stitches are produced by an overlocker rather than fancy stretch stitches found on some sewing machines.
The overlock is normally used to finish raw edges or to sew light jersey like in T-shirts. On many woven materials you can use simple zig-zag for overedging with equal success, but on jersey it often pulls or puckers, so a better solution is called for.
The full stitch is the 4-thread overlock: 2 needles, 2 loopers. The 3-thread overlock is a 1 needle, 2 loopers stitch, it is basically the same in construction. On a 4-thread overlocker, you remove one of the needles, so you get either a wide or a narrow overlock. On a 3-thread overlocker the width is usually fixed and depends on the machine.
This is a 4-thread overlock, the green thread is on the top. The red and yellow threads are needle threads, as you can see they produce a straight stitch on the top. On the underside they produce two rows of dots or little loops, depending on the tension setting. In the above example, the red thread is a bit loose, so you see a row of loops. The yellow thread however has correct tension, so you hardly see anything.
In fact, it is not always “wrong” to have little loops instead of dots on the underside. Thick fabrics often do better with loops as this keeps them from looking squashed. But here is an example of little dots on a thinner fabric:
This stitch stretches because the little dots or loops form folds in the straight stitch, putting away extra length of thread. So when you stretch the jersey, these folds simply open up without snapping.
The flatlock and the coverstitch
These stitches are related to the overlock.
The flatlock is basically a 3-thread overlock done with different tensions and opened flat.
The coverstitch is done with just the lower looper, and with 2 or 3 needles (or more, in industry).
Similarly to the overlock, it makes folds in the needle threads tucking it into the thickness of the material between stitches. These reserves allow it to stretch with the jersey.
The long bobbin straight stitch
But that’s just my grandma’s sewing machine! Yes, very old-fashioned. And very effective for sewing jersey.
These were some of the very first sewing machine mechanisms to be invented: the long bobbin lockstitch type, they emulated weaving with a shuttle, except that the “loom” was now just one thread wide (the needle thread). The mechanisms from this family that are still practical today, are the transverse shuttle (the boat) and the vibrating shuttle (the bullet). Many of these models (but not all!) use the same needles and feet as our modern domestic machines, and as for the long bobbins, they are being made again, so no need to chase vintage ones.
But this is a lockstitch straight stitch, the same as what our modern sewing machines produce, so how is it different when sewn on a long bobbin machine?
It isn’t that different, in fact the stitch is constructed in exactly the same way: the needle and bobbin threads meet, twist, and continue their journey on their respective sides of the fabric.
The secret of the long bobbin machines is in the tension. And a doze of fairy dust as I discovered when trying to sew some nanotex jersey.
Similarly to the overlock, the long bobbin allows to sew with low tension on both threads, so it puts away lengths of thread into the folds between the stitches. Round bobbin machines cannot sew well (if at all) with such low tension, they are particularly sensitive to the tension on the bobbin thread. And because they require a higher tension to sew, they cannot make sufficiently large folds to hide extra thread that would open up as the jersey stretches. Instead, those stitches snap.
Zig-zag stretches because the stitches lie at an angle to the pull! Very effective, but doesn’t make for a strong or a crisp seam. Zig-zag is usually used on flat overlapped seams or for sewing on narrow elastic. For anything wider, better use stitched zig-zag.
Stitched zig-zag and feather
Stitched zig-zag comes in two variants: 3-step and 4-step, which determines how many stitches are in each “leg” of the zig-zag. The overall width remains the same, so the stitches in a 3-step version are longer than in a 4-step one.
The 3-step zig-zag in combination with back-and-forth stretch stitch, produces the “feather” stitch. If the original zig-zag legs are not sewn in a straight line, but themselves have a little zig-zag, it produces further variants of the same thing.
The top line in the above photo is the original 3-step stitched zig-zag with straight legs. The second line is the same with varied zig-zag width along the legs. The third and forth lines are the same with added stretch. The patterns in these two lines are produced with different zig-zag width settings.
There are not many machines out there that allow you to vary the zig-zag width while sewing a pattern, let alone also to add stretch stitch on top. Usually you get some of these stitch variants as separate stitches on the cams or in the menu. The above sample is sewn on New Home 551 by Janome, it is quite easy to understand what is happening. Singer 401G series also allows to make similar settings, but the knobs and levers are mystifying. Plus, it also allows to vary needle position which modifies the stitch in unpredictable ways. Guess which machine I prefer. 😉
Back-and-forth stretch stitch
This stitch is found on many sewing machines. It is also called triple zig-zag (even when straight), flexi-stitch or ZZ-stitch. (I thought zig-zag already was “ZZ”? Apparently not.)
The machine makes two stitches forward and one stitch back, so every stitch is done in triplicate. This works on any stitch pattern – straight, zig-zag or even fancy stitches, such as the “feather” stitch discussed above.
For making seams though, the most useful variant is straight stitch. This works well but only on thick fabrics because instead of one hole between the stitches, there are now three. Three times the needle pierces the fabric where only one is required, often ripping delicate materials and stretching out jersey. In addition, the stitch length is usually limited to 1-1.5mm which is very short and already in itself will stretch out jersey.
Personally, I think that “stretch stitch” is a misnomer since it cannot really be used on stretchy materials. It is a good and strong stitch though, and is excellent for setting sleeves into jackets, sewing back seams in trousers, sewing jeans or anything else that is likely to come under strain during normal wear. Just not jersey. 😛
Single thread chain stitch
This is the original knitted stitch, it stretches with the jersey because it is constructed in the same way as the jersey!
But back to the 1-thread chain stitch.
It looks just like a regular straight stitch on the top side, and it forms a chain on the underside.
In principle, this is the best stitch to use on jersey and knits of all weights and thicknesses. In practice, domestic machines with chain stitch are rare. Oh, they’ve got it in industry, just not for us at home. See my separate post for details. Those solutions do work, but often with mishaps. You can’t always be sure of a perfect stitch, as with your regular sewing. This is why I looked into old long bobbin machines – their stitch, although a little less stretchy by nature, is far more reliable.
Mirror, mirror on the wall…
So which stitch is the best? It depends! 🙂
It very much depends on the jersey – the stretch, the weight, the bulk, all of it. As with all sewing, the best choice depends on the project, so we need all those different stitches. I often use several on the same project because a side seam is not the same as the hem, which is not the same as the neck line…