This past weekend I had to time to play with the Specialty Bobbin Case that I purchased last week. Here's the two bobbin cases together:
You can't really tell any differences in the two exception for the color. The black one is the bobbin case that came with my machine and the grey one is the specialty bobbin case. Here's a close of the specialty bobbin case:
If you look a little to the right and down from my finger you can see a big slot. That slot is what allows the heavier thread to move through the bobbin case.
In looking through my thread collection, I found a 30 wt decorative polyester:
Pairing that with a quilting weight cotton and no interfacing , I played with the decorative stitches on my Lisa machine. Here are the results:
I don't think I really needed the specialty bobbin case with this thread but I wanted to experiment a little. In the above picture, I started with a 3-step zigzag stitch and left all the settings as recommended. I generally keep the thread tension set on 4. This produced a stitch with the upper thread being pulled to the back. This definitely wasn't the look I was going for. Every dark line in the picture above is a change in thread tension. The second stitch I played with was the feather stitch. The other stitches are what available on my machine. With this particular set-up, the tension looked best around 5 to 5.5 on all the stitches. I also decided that all of these stitches would benefit from a stabilizer or interfacing. Oh course, a second layer might work, too.
In continuing my experiment, I have repeated the same stitching above expect I added a cut away stabilizer. Here's the results:
In this example, I did only use the thread tensions between 5.0 and 6.0. Can you see the difference the stabilizer makes in the stitching?
Here are the two samples side by side. The sample on top is the one with the stabilizer. If nothing else, I've learned that these types of stitches really need more support. I suspect that a heavy dose of spray starch might even do the trick. This is what many heirloom sewists do.
Next, I will be experimenting with pearl cotton and I will probably move to Behemoth as that machine has far more options to choose from. The pearl cotton that I have is a size 5, I think. This will require hand winding on the bobbin.