Thursday Tip with Hali - Using a twin needle
Thursday Tip // Using a twin needle
Sewing with a twin needle may seem complicated but it’s not as hard as you might think! As with other needles there are twin needles for knits and wovens and even jeans! Two rows of topstitching in one step? Heck yes, you can!
Twin needles can be used for hemming knits, topstitching a neckband, binding armholes or creating multiple rows of decorative topstitching. They sew two parallel straight lines of stitches via the needle threads and the bobbin thread winds back and forth creating a zigzag pattern on the underside of your project.
The trick is finding the right needle for your project. The picture below shows a Schmetz brand twin needle labelled “Stretch”. It is marked for a domestic sewing machine (130/705 H). This needle will work for knit fabrics including those with spandex content. The number at the bottom, 2,5/75 means the needle size is 75 (for lightweight fabrics) and the distance between the needles is 2.5mm (as shown with a ruler).
You can find universal twin needles in different sizes or widths between needles as well as needles suitable for denim and heavyweight fabrics, like jeans.
We always recommend testing the twin needle on a swatch of fabric first to see if the needle and thread is a good match. For the denim sample below I used a jeans twin needle (4,0/100) and Gutermann Mara 70 topstitching thread and it worked great.
If you are getting puckering or tunnelling in your stitches lower the tension slightly or consider using a knit hem stabilizer like Heat n Bond Soft Stretch. It is a fusible web adhesive, similar to interfacing which will give your fabric a bit more stability when stitching.
A note about backstitching
While using a twin needle I don’t recommend doing too much backstitching. There’s a lot going on with all the threads so I’ve had more success without trying to backstitch. If you are hemming before constructing, let’s say a tshirt, then the stitching will be caught in a side seam and won’t unravel.
If you are hemming in the round as a last step then when you get back around to the start of the hem, just continue stitching over top of where you started and this will help to lock in those threads. For extra security, cut longer thread tails and weave them to the inside of the garment with a hand sewing needle.
How to thread a twin needle:
1 - Insert the needle as you do any other needle, then thread your machine as normal with the first thread spool in your left hand spool pin. You can leave the thread loose for now or thread it through the left side needle. If you have a tension disk that is visible from the front of your machine, you may notice a piece of metal in the middle of it. The left hand thread goes to the left of the disk.
2 - Use your additional spool pin and a second spool of thread, and thread following the same thread path. The right hand spool of thread should unspool in the opposite direction of the first one. This helps with drag tension at the top of the machine. If applicable, the right hand thread goes to the right of the disk in the tension.
3 - Thread the left hand needle with the left hand thread and the right hand needle with the righthand thread. This helps ensure even tension and stitching.
Hot tip: Since you will be stitching on the right side of the fabric, use your pins to help mark the edge of your stitching line so you can be more confident you’ll catch the raw edge in the stitches (picture below).
