This is rather strange looking attachment, wouldn’t you say? I likened it to a preying mantis because of how the thread arms reach out and the bottom arms crisscross…
Nevertheless, this is a very, very scarce attachment to find indeed! We know this attachment is expensive. It is quite a collector’s item not just because of how scarce it is to find one (in complete condition with attachment, both spool arms, original box, manual, and tiny thumb screw), but also one that is working and functional! In fact, several years ago we quit buying this particular attachment unless we could personally sample and test it before selling. After having several come in the shop at high prices that ended up not working properly because of some minute error in precision, we have been leery about buying them untested. I wish they all worked as well as this one!
It is imperative that each upper and lower clamp grip precisely over the thread crossing arms like you see in the photograph above.
The Two-Thread Embroidery Attachment varied in color over the years. Sometimes they would be chromium and sometimes they would have a blackside finish. You can see the differences in the finishes in the images above. Some were even a partial with a blackside attachment and chromium arms or vice versa.
You can see in the antique baby garment how a similar effect was accomplished.
As you can see in all the samples above that you can use the standard thumb screw, however, it does make it easier (the thread is less likely to get caught) if you have the original teeny tiny thumb screw that would have been included originally with the attachment. It is so tiny that they were not thought to be a thumb screw when tossed into a sewing cabinet drawer. Who knows how many of them have been tossed over the years. Be sure to watch the video below to see what the original thumb screw looks like.
The best thread that I have found to work with is the Sulky 12wt thread. It’s a bit thicker than normal thread, but still lightweight enough that the threads actually criss-cross to achieve the decorative effect the Two-Thread Embroidery Attachment is so famous for.
If you are blessed enough to stumble upon one of these at a local estate sale, etc. and it works — be sure to use a stabilizer with your fabric when you test it, just like all machine embroidery work. Read through the instructions and work very, very slowly and begin by practicing with straight lines. As you gain more confidence, use a traced design and work with curves and points.
You can experiment with different threads to make one side stand out from the other.