Invisible thread question.
 

Which is best nylon or poly? I know nylon stretches like crazy and can cause problems when using in the machine. Poly doesn't stretch. Nylon is softer, more like thread. Aurifil mono is nylon. Most of the other top brands are poly. I can buy both but just wondering what most prefer.

Watching this thread with interest because I have the same dilemma.

I read that the Nylon ones cannot handle the heat of the iron. So I stick to poly. I have used it quite a bit (different brands) and make sure that I have a net over the spool (it loves to unravel) and I make sure it stands upright. It tends to do better when the thread comes up and over rather than sideways.

I think that Sulky is polyester which is what I use. The nylon stuff that when it first came out in the 80s was like the line used on fishing reels. YUCK!! I gave away those cones.

Aurifil being a quality brand makes me wonder why nylon mono filament from them. It does melt when the iron is on high heat.

I have a cone of Superior Monopoly (poly) and Fil Tec Essence (nylon). Quite honestly I really don't see or feel much difference between the two when it comes to performance and how it quilts out. I like them both equally in my LA.

I like the Mono Poly best, and I have tried several types/brands. Mono Poly gives me less issues than the others. But I have Sulky nylon in my sewing machine now, and it doesn't really feel bad. It just tightens up every so often, I have to keep an eye on it.

I only use whatever brand of monofilament thread on top, never in the bobbin. That has never worked out well for me.

(I have never had issues with any of them melting, I do keep my iron the highest setting, but maybe it's not as hot as those who have the issue.)

I have used it in newer and older machines, by the way.

Sulky has a nylon that is very thin and pliable now.

I have used Aurifil invisible thread since I started quilting 5 years ago. At the time I started using it, I did not know that the thread was made from nylon. I have enjoyed using this nylon thread and have never had a problem with it. Frequently, I draw a design with a Frixion pen (I know many people don't like these pens), quilt it with the Aurifil thread, then, with my iron on cotton, use steam to remove the Frixion markings. So far, I have never melted the thread. Maybe I have just been lucky. At any rate, some of the quilts have been washed many times and the invisible thread that I used for quilting is holding up well. I'll be honest, if I had known that the Aurifil thread was nylon, I would not have bought it; but I am very, very pleased with it and enjoy FMQ with Aurifil invisible thread.

I'm not sure why Aurifil uses nylon either (though I'm sure they have some good reason). They do have an ironing guide for working with their mono threads:

[h=5]Ironing Guide[/h]
<section class="av_textblock_section" itemscope="itemscope" itemtype="http://schema.org/CreativeWork"> 150 c° – 302 F° Optimum Temperature. While protecting your stitches from the hot plate with a cloth.
160 c° – 320 F° At this temperature the thread will start to shrink by 2%
+240 c° – 464 F° At this temperature the thread will start to melt

I guess that makes sense. Thread is a fiber. We wouldn't iron nylon or polyester fabric on the Cotton setting, so I guess it's only logical that the thread would also take a lower setting. I looked it up & most irons hit 150C on the cotton/poly blend setting.

Honestly, though, once I've quilted it, I don't press my quilts anyways.


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