I wanted to share some of my experiences and thoughts on monofilament (invisible) thread. Invisible thread and can usually be found in a clear color and a dark gray smokey color. I have heard legend that there is an invisible thread out there that is not shiny (If you've used one please share! I don't know where to find these!) but the ones I have used tend to be shiny if you use a lot of it. I mostly use this for applique and it doesn't seem to be too much of a hindrance.
In my opinion, there are three things that will help to make your monofilament sewing experience fun and not send you screaming stomping and swearing at your sewing machine.
Use a QUALITY invisible thread.
Use the correct needle.
Drop your top tension - and don't be afraid to hit zero.
To date I have only tried Dritz's nylon monofilament (found at Jo Ann Fabrics, Walmart, and other big box type craft stores), and Superior's Polyester monofilament. Please believe me when I tell you it is like NIGHT and DAY between the two.
I know I'm going to sound like I'm terribly biased towards Superior Thread, and I promise you they have no idea who I am or where to find my blog, but I do love their thread!!! I tend to keep going back because I have such good luck with them.
TRULY the reason I love this invisible so much more than the Dritz is because it's not stretchy. From what I understand Superior's is a polyester...so it's very very fine but also very very strong. It's also got a bit more substance to it's feel than the nylon monofilament and you can even see that in the photo above. If you pull on the end of the polyester invisible it stays pretty taught, there isn't much give, it's not easily broken, it feels more like a sewable thread. If you pull on the end of the nylon invisible it stretches like a fishing line...there is a stretch to it, it sort of weakens when pulled taught...it also breaks much more easily.
The reason stretch is such an issue is because when you go to thread your machine, the stretchy nylon tends to stretch through the tension discs and just seem to have difficulty weaving it's way down to the needle smoothly. Of course with practice you could make this work - you could make just about ANYTHING work...although it can be VERY frustrating. If you haven't used a clear thread before or you've had a bad experience I really urge you to try a better quality invisible.
Another reason I prefer the Superior brand - the Dritz nylon monofilament tends to yellow over time. I've had both of the spools of thread shown above for about two years. The Superior brand didn't yellow at all - but when I purchased the Dritz brand it was nice and crystal clear just as the Superior. I truly don't know if it effects the quality of the thread any - but I'm hesitant to use a yellowed thread...and it makes me wonder how it might effect my finished quilts.
Now to be fair, I will mention that Coats & Clark has a clear invisible thread now and I am itching to try it. It's less expensive (though the Superior brand is only $8 and it lasts a VERY long time) per spool but I don't know much about it other than that. Has anyone out there tried it?
Needles and tension sort of go hand in hand. Generally the smaller the needle the finer the thread your using so the lower the tension. (See how everything just plays together?) When using invisible thread you want a fine needle. The recommendations I've read seem to be something like a 60/8 sharp. You really want to make sure you use something smaller though or else you start to get skipped stitches and looping. (Use a sharp, top stitch, or embroidery needle - the tip of the needle is finer, you'll leave less gaping holes this way.) I always have 70/10's on hand because I do so much with polyester threads so I just used one of those and it worked well. That may have to do with it being polyester though, as it is a bit heavier than the nylon. The hole is a bit bigger than I'd like on the example I'm going to show you - but still, it's pretty invisible! If you are doing something for show or you really want to hide those holes, wet the quilt and let it air dry - the fibers will settle upon drying and the holes will disappear.
Below is the project I'm working on now - I used the combination I show in the above picture. Superior brand clear polyester monofilament and a Schmetz 70/10 microtex sharp.
Up close you can see - it's hidden pretty well! I just used a tight zig zag stitch all the way around the applique. I also have my tension set about half way between 0 and 1.
Now below is an example of an old project where I used the Dritz nylon monofilament...this was one of my first attempts with invisible thread, so I believe I used a 90/14 universal needle and had my regular tension settings. I had a heck of a time getting it to look nice from the back - and - it's not very invisible is it? I had lots of breaking and stretching and you can't see them here because they are stabilized by the other fabrics underneath, but areas where there is nothing to stabilize the fabric I have the worst puckers. Those can be eliminated by two things - lowering tension, and adding a light wash away or tear away stabilizer behind the applique if you continue to have puckering or pulling. I have yet to need to stabilize anything with the Superior monofilament though.
So there's my take on invisible thread!!! If you have any recommendations for other brands or tips you'd like to share please do - I would love to hear them and try for myself! :)