Learn to Sew: How to Zig Zag Stitch

Welcome back to our Learn to Machine Sew series for beginner sewers! So far we’ve only worked on the straight stitch (and backstitch) and I think it’s way past time we start branching out into the other important stitch: the zig zag!

The zig zag stitch is wonderfully useful because, as the name implies, the stitch doesn’t just go in a straight line, but back and forth in a zig zag, covering more fabric and being more visible. Zig zags are useful for keeping fabric edges from fraying, joining cut fabric edges, general sewing when you need some stretch or decorative sewing, among many other uses. Today I’m going to focus on how to adjust this stitch and a couple of ways of sewing it. Want to learn more about how to zig zag stitch? Then read on!

Take a look at the needle in the above pictures (and, for the love of God, please don’t pay any attention to all the fuzz. My machine’s in bad need of a good cleaning.). When you have selected the zig zag stitch, you will see that the needle moves from left to right and back to the left again as the feed dogs move the fabric under it. This is what creates the zig-zag effect.

Now you give it a try. Select the zig zag stitch on your machine (check your owner’s manual if you’re not sure which one it is). On my machine it’s program #5. If you have an electronic sewing machine, there will be a general preset for each stitch. On my machine it’s stitch width 3 and stitch length 1.5. What does that mean?

If you recall from the straight stitch lesson, stitch length refers to how quickly the feed dogs (don’t know what those are? Check out the sewing machine anatomy lesson.) move the fabric under the needle, and therefore how much space there is between the points where the needle pierces the fabric. So a longer stitch length means there is more thread and fabric between the holes the needle makes.

It’s the same concept for the zig zag stitch, too, however stitch width is also very important for this stitch. Stitch width refers to how much the needle moves from left to right. For the straight stitch, it is zero. But the bigger the stitch width, the wider the zig zags stretch across the fabric.

Take some scrap fabric (I’m using a piece of folded up bedsheet [left over from my son’s ghost costume] in all the exercises of this lesson), fold it in half and iron it, then thread your sewing machine with thread of a contrasting color so you can see it better. Let’s first experiment with different stitch widths. Select the zig zag stitch and set it to stitch width 3, stitch length 1.5 (which I’m abbreviating as 3 – 1.5 in the photo above). Sew a line at this setting. Now change the stitch width to 7 (or the highest setting you have) and sew another line. And finally sew another line with the lowest stitch width (in my case, 0.5).

Now compare them. The lowest stitch width is the closest to a straight line and the highest stitch width is really wide. Very wide zig zag stitches can make the fabric pucker, though, as the stitches naturally pull together. You can see this effect in the 7 – 1.5 zig zag stitch above…

…and also how it looks on the back of the fabric. For this reason, I pretty much never use a zig zag this wide.

Now let’s do the opposite, experimenting with the stitch length. Once again, sew one line of stitch with stitch width 3 and stitch length 1.5. Then sew another line with stitch length 0.2 (or the lowest you have) and yet another with stitch length 5 (or the highest you have). Compare them. The lowest stitch length creates stitches that are pretty much on top of each other, which I don’t like using because they have a tendency to pile up on each other and get stuck in the feed dogs, blocking the fabric. That’s what happened with my example above. Not very pretty.

Generally you will use stitch width and length somewhere in the middle. But how do you know which to use? Stitch width 3 and stitch length 1.5 is a good starting point, but it’s important to start to get an idea what happens as you move those values around. I was going to prepare some practice sheets to use with zig  zag, but as the thread pulls from side to side, it tended to rip regular printer paper, messing up the stitches, as you can see above.

So instead let’s create a sort of zig zag stitch library on fabric that you can refer to in the future. Cut a long piece of woven fabric, fold it in half and iron it. Then on the top,write all or most of the possible stitch width/length combinations possible on your machine. Just use a regular pen.

I started with a low stitch width and low stitch length (1 – 1), and bit by bit raised the stitch lenth. When I got to the highest stitch length, I started over again with a slightly higher stitch width and, again, a low stitch length (2 – 1), which I raised bit by bit.

I ended up needing two pieces of fabric to get mine in from 1 – 1 to 7 – 5. If you study the shapes of the zig zags, you’ll see that no two combinations are exactly the same.

Look at the different between the zig zags with the lowest and highest stitch width (picture above). I suggest you save these pieces of fabric so that you can decide which effect you’re looking for next time you need a zig-zag stitch.

Now that you’re getting an idea of how to adjust the zig zag stitch, let’s look at how to sew it! Prepare more fabric in the same way as before, and draw some straight lines on it with a ruler.

Position the fabric under the needle so that the line goes right into the mark at the center of the machine foot. Then start sewing with a zig zag stitch. Try to keep the line in the middle so that the stitches reach an equal amount on either side of the line. Then continue the exercise with other stitch widths/lengths on other drawn lines. The wider the stitch, the easier it is to stay on the line.

Do you see how my stitches look darker at the end (the bottoms in the photo above)? The zig zag stitch, just as we’ve already mentioned with the straight stitch, can pull right out of the fabric if it isn’t tacked down. But luckily you can use the backstitch with the zig-zag, too! Don’t forget to always backstitch at the beginning and end of your stitching! (Unless you will be sewing back over the beginning, in which case you can skip backstitching there.)

Now let’s look at one last way to sew the zig zag: to finish off the cut fabric edges to avoid fraying. Cut the edges of one of your practice pieces and position it under the presser foot so that the edge is a little bit to the right of the center of the foot. Take a look at the picture above to get an idea of how much.

Now sew right down that fabric edge with the zig zag stitch. The left side of the stitch will be in both/all layers of fabric, while the right side will fall beyond the edge. This way the thread pulls in slightly the cut fabric edge, keeping it from fraying in the wash or with use. This is incredibly useful for any project with woven fabric that could potentially be washed. The last thing you want is for an item that you spent hours sewing to fall apart in the wash!

UPDATE! (Jan 17, 2015) I totally forgot to show you how to zig zag in corners, so I’m just adding it on here!

Let’s pretend that we have two pieces of fabric, the top fabric with a corner cut in it. To avoid pinning and to make it clearer, I drew immaginary green fabric on the actual white fabric. #1 above represents an inner corner and #2 an outer corner. When sewing the edge of one fabric on top of another, we want the zig zag stitch to be completely on the top fabric with just the very edge of one side passing over onto the other fabric. Let me show you.

Let’s start with corner #1. Start at one end, with the top fabric (in our case, the green area) on the left side of the presser foot. Position the fabric so that the right side of the zig zag stitch falls just to the right of the drawn line. Zig zag stitch down the line until you get to the corner. With an inner corner like this, you will then need to continue a full stitch width beyond the corner, stopping with the needle lowered in the fabric to the left (top photo). You can tell if it’s the right amount beyond the corner by raising the presser foot and turning the fabric (bottom photo). It looks the right distance from the corner, but you can test it by lowering the presser foot and checking if the right side of the zig zag will again fall just to the right of the line continuing in the other direction. If it’s at the right distance, continue sewing. If it isn’t right, turn the fabric back to how it was before and sew another stitch, but remembering to always stop with the needle in the fabric on the left side.

By doing this, you sew over your stitching in the corner, but it’s nice and neat (and reinforced in what could be a weak point), and the stitching is positioned correctly on both sides of the corner.

Now let’s look at corner #2, an outer corner. Again, start at one end, with the top fabric (the green area) on the left side and so that the right side of the zig zag stitch falls just to the right of the drawn line. Zig zag stitch down the line until you get to the corner. With an outer corner like this, you need to stop with the needle down in the fabric in to the right, but just beyond the top fabric edge, or line in our case (top photo). You can check if it’s far enough along by raising the presser foot and turning the fabric (bottom photo). If it’s good, continue sewing. If it isn’t right, turn the fabric back to how it was before and sew another stitch, but remembering to always stop with the needle in the fabric on the right side.

Again, you are sewing over your stitching in the corner, but it neat and strong.

Voilà… perfect zig-zagged corners, without any messy stitching going over the edges!

Like I mentioned before, the zig zag stitch can be used many ways, but we will deal with them a bit at a time. For now, I suggest you practice it a bit (also on curved lines/edges!) and get a feeling for how the stitch width and length adjustments work. Then later this week we’ll have a project tutorial using this stitch! (edit: here it is!)

Did you enjoy this lesson on how to zig zag stitch? Take a look at the other lessons in this beginner’s sewing course!