For successful twin needle sewing, I use a thread stand, aka Thread Nanny.

Twin needle sewing is great in theory.

But, in practice, it’s often a frustrating exercise in adjusting tension.

It’s a series of minute tweaks to prevent tunneling — the dreaded ridge that forms between two lines of parallel stitching — and popped stitches. A one-step-forward-two-steps-back operation. UGH.

If mastering twin needle sewing is a hassle, why bother?

Keep reading to discover the case for twin needle sewing and how I got comfortable with this technique, thanks to one simple tool.

Why Twin Needles Matter

You should get comfortable using a twin needle for three reasons:

1.) Function (and Fakery)

Twin needle sewing can look like (from the right side) two parallel lines of straight stitching. (This also is what the output of a coverstitch machine looks like.) On the bobbin (wrong) side, there’s one line of zig-zig stitching, which gives twin needle sewing stretch — perfect for hemming knits. In short, you can “coverstitch” a knit hem with a twin needle.

2.) Beautification

Perfectly parallel lines of decorative stitches? Yes, please. You could have fun with different thread colors, too. Be sure to check your machine manual to discover which decorative stitches work with a twin needle.

3.) Toolbox Expansion

If your machine can do twin needle sewing, why wouldn’t you want mastery over it? Work all the functions, baby! (You paid for them.)

Twin Needle Sewing Tests

Twin needle sewing can be fickle. That’s why testing is imperative to success.

I tested sewing a knit with a twin needle two ways:

  • As directed in my sewing machine instruction manual.
  • With a Thread Nanny. The Thread Nanny is a thread stand that looks like a small shepherd’s hook through which you feed thread. Mine has a cast-iron base and metal pin on which to stand a spool. You can use any kind of spool — cone or standard — with a Thread Nanny.

For your reference, here are some of the twin needle sewing instructions in my manual:

Here's a look at instructions on twin needle sewing from my sewing machine manual.

In short, you place a second thread spool on an addition thread pin, and the two thread spools unwind in opposite directions.

Getting back to the tests…

I sewed lines of straight stitches on grain set at 3.5 wide and 3.5 long in a double layer of mid-weight cotton T-shirt fabric. I used white Wooly Nylon thread in the bobbin (for maximum stretch) and all-purpose polyester thread for the topstitching — black for the left needle and red for the right needle. The presser foot pressure was set to 3 (medium).

I used a stretch Schmetz brand twin needle, size 2.5/75, and a regular presser foot. I went with a stretch needle because I was sewing a knit.

The variable I changed between instruction manual sewing and Thread Nanny sewing was upper needle tension. I did six levels of upper needle tension, from 2 (lowest) to 7 (highest). Settings 3, 4, and 5 are in the middle of my machine’s upper needle tension.

I played with the upper needle tension because the bobbin side of the stitching had the most problems. When stitching is balanced, you don’t see top thread on the bobbin side or bobbin thread on the top side. And when you see top thread on the bobbin side, that means there’s a problem with tension on the top. It’s an opposites thing:

Top thread on bobbin side → Adjust tension on top thread
Bobbin thread on top side → Adjust tension on bobbin thread

When sewists troubleshoot twin needle sewing issues, they often adjust the bobbin thread tension. The tension of the bobbin case is calibrated with precision and should be tinkered with as a last resort with A LOT of caution.

Test Samples: Instruction Manual vs. Thread Nanny

Instruction Manual

Here's a look at twin needle sewing outcomes with changes to the upper thread tension.

A touch of tunneling starts in 5 (it’s hard to see in this pic). The topstitching looks too tight in 6 and 7, and it looks too loose in 2. On the bobbin side, 2,3, and 4 are too loose. Settings 6 and 7 look the best on the bobbin side, with 7 having the least amount of topstitching peeking through. I think 6 has the best overall twin needle sewing.

Thread Nanny

Here's a look at twin needle sewing outcomes with changes to the upper thread needle tension.

A little bit of tunneling starts at 7 (again, trust me). The topstitching looks slightly too tight in 7, and waaay too loose in 2. On the bobbin side, 2,3, and 4 are too loose. Settings 6 and 7 look best on the bobbin side; 7 has almost no red peeking through. I think 6 is overall best here.

My Twin Needle Sewing Choice

After my tests, when I need to complete twin needle sewing, I’m going for the Thread Nanny. Here’s why.

This is how I set up my Thread Nanny for twin needle sewing.

Tension. There’s less tension on the Thread Nanny spool of thread as you work it through the machine to the needle. The thread unspools smoothly. (This pic shows how I set up the Thread Nanny next to my machine.)

When I use the extra thread pin, per my sewing machine manual, for twin needle sewing, the thread on the extra (upper) pin gets very close to winding around the lower thread pin.

Tangling. Thread from the Thread Nanny doesn’t wrap around the sewing machine thread pin. Sometimes a small spool cap (on the yellow spool) can’t keep thread from the extra spool pin (red) from wrapping around the yellow thread pin. In the pic I circled where the red thread comes thisclose to the pin with the yellow thread. Let me tell you — it SUCKS to have thread from the upper pin wrap around the lower pin.

Threading. The twin needle directions in the manual call for threading the two strands through the machine in opposite directions (one strand is threaded over and the other is threaded under — like opposite rolls of toilet paper). This over/under malarkey isn’t necessary with a Thread Nanny.

The extra spool pin, to be used during twin needle sewing, dips down.

Tipping. The extra thread pin attachment kinda tips down… and I don’t think that’s great. You can see it in this picture; if the pin were straight, it’d be the light gray. I imagine the downward tipping puts more tension on the red thread, because instead of unwinding straight with ease (or maybe a little higher than the interior of the machine, thanks to gravity), the thread dips down and then is pulled up a touch before it passes through the machine.

As you can see, there’s not a big difference visually between the instruction manual and Thread Nanny sewing samples. I think the Thread Nanny’s were a touch better, but it’s mostly a wash.

In the end, I choose the Thread Nanny for twin needle sewing because it offers a better, less-tension-filled experience.

OK, over to you: How much have you played with twin stitching? What’s your take on a Thread Nanny? And what’s your top twin needle sewing tip? Please share in comments! Thanks for reading.

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