A double needle (or twin needle) is a super tool for sewing knit (or stretch fabric) garments. Use it for a skirt, top, sleeve, or pant leg hem (like my free Basic Leggings for Girls Pattern). The double-needle stitch is much more flexible than a regular straight stitch so that means no popped threads when you accidentally stretch the hem too much, and if your sewing machine is capable of zig-zaging, then it can do this too.
It is used mainly for hems - not for sewing the seams. Here are my tips for how to sew stretch fabrics (including the seams).
In this blog post let me show you how to sew with a double needle and any sewing machine that can zig zag...
How to sew a Professional Double-Needle Hem
Serging the edge first will make your finished hem look very similar to a coverstitch hem (that's the fancy machine that is used on most store-bought garments). But serging is not really necessary since knit fabrics don't fray.
Step 1: Prep your edge.
Serge the bottom, if desired. Then press the hem the desired amount.
Step 2: Prep your sewing machine.
You will need two spools of thread (fill an extra bobbin for one if you need to) and two spool holders. If your sewing machine doesn't have two spool holders, I've seen where people tape a pencil or straw vertically next to the first spool holders to make a temporary one. You could also use a free-standing thread holder.
Install a double needle on your sewing machine. Thread the machine as usual with the first spool of thread and insert it in the needle of the right.
Thread the second spool (or bobbin) of thread second, in just the same way. It will seem strange to thread two threads in the same spot, but it will turn out fine. The second thread should go into the needle on the left.
Step 3: Test on a scrap of fabric.
Use a straight stitch. I usually lengthen my stitch to 3 or 3.5 for knit fabrics. Backstitching is fine with a double needle. You don't need to stretch the fabric as you go.
Step 4: Sew the double needle hem.
As you can see from the picture above, I strategically pressed the hem on this skirt along the bottom stripe so that my row of black stitches would follow the next black stripe up. It won't be visible for most of the hem.
Here are examples of what the wrong side of the hem would look like with and without the serged edge. Like I said, the serged edge is not necessary. But it will fake your friends out so they think you bought the skirt at the store.
FYI: The instructions for the easy Faux-Wrap Pencil Skirt above is in my book Just For You, and next week Stephanie Kendron (who hosts the Modern Sewciety podcast) is going to share the skirt she made! Join our facebook group to learn about our year-long selfish sewing sewalong. Come back every Wednesday to see more!
This is just another one of my Sewing 201 posts... these are posts where I share a technique to take your sewing to the next level. Check them all out. :)