How to Zigzag Stitch

Hand-Sewn Zigzag Stitch for Protecting Seams

Zigzag stitches are used to protect the raw edges of material. The zigzagging thread prevents the edges of the fabric from unraveling. There are also decorative types of zigzag thread, but for our purposes, we will be creating an overcast stitch type of zigzag stitch.
Step 1: First, let's anchor the stitch.
What can I use a zigzag stitch for? Nearly all sewing projects could benefit from a zigzag stitch. This secures the edges of each seam to keep the fabric threads from unraveling. Sewing machines can quickly take care of a zigzag stitch, but if you are hand sewing a small repair, it may be quicker and more convenient to complete the zigzag stitch with a needle and thread.

Anchor the Stitch

Put the needle through the fabric, pull through. Be sure that the threads are lining up and that there are no tangles on the other side of the fabric.
Make a single straight stitch to anchor the beginning of your stitching. End on the 'right' side of the fabric.

Begin the Zigzag with an Overcast Stitch

Go around the edge of the fabric, and insert the needle in the 'wrong' side of the fabric, pulling back up through the right side.
Continue, with stitches that wrap the edge as you work. This is creating an 'overcast stitch up the length of the edge. Go all the way to the top of the edge. If you run out of thread, anchor the end of your overcast stitch with a small straight stitch before knotting off and clipping the thread on the wrong side of the fabric.

Start to Zigzag over the Edge

I just did a bit of stitching for our tutorial, but you'll typically want to go all the way up the edge of the fabric.
Pull the thread up through the hole of the previous stitch.

Create the Zigzag Stitches

Go over the edge, and through the next hole that was previously made in our stitching, as shown. This will create another line of overcast stitches that tilt in the other direction.
Continue down the edge of the fabric, making the zigzag pattern shown. For fabrics that are particularly susceptible to unraveling, make sure your zigzag stitches are more narrow than those in our example.