I've used Sulky invisible polyester thread and get along well with it. Bought it at JoAnn's ( take a coupon with you). Have yet to try my Superior thread I bought at a quilt show

Thanks for clearing that up ... I had wondered about it.

Also, re "Wonder Invisible" mentioned by SewingSenior.
Have been wondering if there is a product by that name?

Or should it be the InvisaFil thread by WonderFil?
https://www.wonderfil.ca/invisafil/
https://www.wonderfil.ca/longarminvisafil

It's a 100 wt thread, fine as can be, yet works well for FMQing because it is still a strong thread.

I've also used it for hand sewing for EPP, applique work, and even on bindings.
Comes in 60 colours, but because it is so fine, it is virtually invisible.

I've used Fil-Tec Essence, which is invisible, and works very well. I do need to loosen top tension on my Juki quite a lot though.

I also use Invisafil. It comes in colors, but as QuiltE said, it's so fine that it's virtually invisible.

There are two 'colors' of invisible thread - clear and dark clear. Sounds weird but the dark clear works better on dark fabrics, less shine. But, a word of caution. Please do not use them on a small child's quilt. Think of it like fishing line - it will not break easily. This means if a bit comes unsewn, it can wrap around a toe or finger and strangle it.

I've used Sulky and (I think) Gutermann with no problems----except, of course, I can't see the darn stuff when I'm trying to thread the machine! I guess that's why they call it "invisible".

I like the Superior thread mono poly the best. I don't know about using it on a long arm as I don't have one. I always had trouble with the bobbin thread sometimes pulling to the top since it is so thin. I am using invisible thread now on a project with regular thread in the bobbin. Someone suggested using a really fine needle, I am using a size 60/8. This makes a tiny hole in the fabric, too small for the bobbin thread to pull thru. This solved my problem. I hope all of this info helps.

I do a lot of machine applique with monofiliament and just took a class with Karen K. Buckley. We brought mono fil thread on our supply list for a class, but when we got there she had YLI for sale, and it had much less sheen if you are trying to hide the stitches. I am doing a king size Kim McLean quilt, and was amazed to see the difference when I tried the YLI. So my large spool of superior will be on the shelf for some other project now!

I've not used the invisible thread for quilting. I have used it for machine applique, on one of my vintage machines, and I can assure you, you will need to loosen your top tension -- try stitching something similar (even make a sandwich from small scraps) and try that. I did have a hard time at first with my machine -- my sewing machine mechanic (my son, who worked 14 years as a sewing machine mechanic) went through the machine, and discovered it needed some adjustments. Some machines can be very "fussy" when it comes to invisible thread. I've used the Gutermann thread and it does a great job. I suspect the problems I had rest firmly in the fact that my machine needed some adjustments, timing, needlebar placement, etc., things I do not attempt to do myself. But I found that the top tension will need to be adjusted on my machine when using invisible thread.

I like Superior Thread invisible and Sulky invisible. I even use it in the bobbin, but care MUST be taken! I usually hand wind the bobbin (sometimes I use the BobbinWinder on slow). I also reduce the top tension to the next step up from zero. Having said all that, I have done several quilts with invisible thread and had no problems with it. Enjoy.

I failed to include the maker name which is YLI. Here is a link for the thread.
https://www.amazon.com/YLI-Corporati.../dp/B00A2GSI3I