First of all, today's monofilament thread is not the fishing line-like product of years ago. It is super thin and flexible. Monofilament thread comes in two compositions: nylon and polyester. I haven't used any nylon monofilament since those fishing line days, but I hear it's just as good as the poly, though a bit less heat tolerant so it may need a cooler iron. I use the polyester version and have been using Sulky's brand.
|Can you see it? Every seam has been stitched.|
The biggest tip is to feed the thread off the spool without twisting. This means it needs to come off of the side of the spool when straight wound. My Janome 6600 has a great set up for spools fed off the top for cross wound and less finicky threads. But I have to be creative to get a spool to feed off the side. I use a spool cap upside down close to the top of the spool pin and then skip the high thread thingy, then thread the rest as usual. You can see this better in the first picture of this post. For most machines, use the vertical spool pin and make sure the spool unwinds freely.
The second tip is to use a very low tension with this thread. It is stretchy and tends to 'create' extra tension via the stretch. I use a .75 to 2 tension on my machine, though each machine is different. Too high tension will result in the bobbin thread popping to the top (you may actually see the thread coming up out of the hole when the stitch forms!) and/or break the invisible thread
Tying off- The thicker fishing line version of this thread from days gone by was a total bear to knot. The newer threads are much easier to tie off or knot, but they still have a tendency to come untied or have ends pop out from the project. I almost always knot these thread ends by stitching in one place and then burying the ends very well.
Needles- I prefer to use a smaller needle with this type of thread, usually an embroidery needle, size 75/10. The thread is very fine, so you don't need a huge needle and resulting needle hole unless the fabric of the project requires a heavy needle.
In the bobbin- For quilting with monofilament thread, a fine thread in the bobbin is a good choice. I use monofilament in both the top and bottom when I finish a binding by machine and have not had to change my bobbin tension at all. Though it usually requires a top tension of less than one on my machine.
I hope you find these tips useful. Monofilament is a great thread for certain situations, especially when there are multiple colors of fabric and you don't want to keep changing thread colors.
Once I came out of the house, frustrated, to tell my husband that I couldn't find my invisible thread. Our neighbor, to whom the hubby was speaking, found it quite funny!