Tips for Using Monofilament

In my post "Quilting Away!" last week, I was using monofilament thread for some free motion quilting stitch-in-the-ditch (SID), also known as invisible thread. Afterwards, I had a few folks ask questions about this thread. So today I'll give you my best tips for using this handy, yet sometimes finicky thread.

tips for using monofilament thread

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.

free motion quilting stitch in the ditch
Can you see it? Every seam has been stitched.
I would like to compare a few other brands, but this stuff is so thin it lasts a very long time. Most makers carry it in clear and a darker version, usually referred to as "smoke". This is good when using it on darker colors. Some monofilament threads have more shine than others and that can detract from the camouflage effect of this clear thread. I hear YLI's version and Superior Thread's Monopoly are pretty popular.

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!


  1. Thank you Amy! This was very helpful.

  2. I've only seen the poly that's quite shiny and I know there's a brand that Karen McTavish uses that is very low shine. I've had no luck locating it, though. Not having to change thread colors is a huge 'plus'!!!!!!

  3. I like the sulky brand as well, though I have a spool of monopoly yet to test. I used So Fine in my bobbin and it quilted like a charm.

  4. Very interesting Amy. I do have a fear of using this thread but it does seem I should give it a good try! Thank you for your thoughts.

  5. You are a big help. I have been a little hesitate to use filament thread. I'll give it a try. Thanks Amy.

  6. I just used monopoly as a change out on a quilt with a dark backing & light front. I could not get enough adjustment to prevent pokies on the dark/light thread combo so switched out bobbin thread to monopoly. I had only tried it on my longarm once before with difficulty so I've been scared to work with it again but had no trouble this time. But wishing I had had smoke because the clear was too shiny for the navy fabric.

  7. Great tips and thank you for sharing them. I haven't tried this thread yet but will at some point.

  8. I have used monopoly and YLI and like the YLI better in that it comes crosswound on a mini cone which feeds so much better through my machine. A few very tiny stitches at the beginning and end of the stitching line really help to lock the thread. Good look on the ends if the line requires a seam ripper. BTW ripping out invisible thread is accomplished much more easily from the visible bobbin thread side. LOL it took me way to long to figure that out.

  9. What is this item you called a"sock". I'm a one year old quilter with lots to learn and this mono. Thread keeps getting all wound up on its self as I sew

    1. Ummm....I don't see where I used the word 'sock' in the post above? Maybe you came across something where I was talking about a thread net? It's been 6 years since I posted this, so I am unsure. Thread nets wrap around a spool or cone to keep thread from getting tangled around the spool/cone.

  10. Thank you! It worked like a dream, wall hanging complete!