thread choice?
 

I purchased a used Pfaff longarm, and the dealer suggested a 40wt. cotton thread.

What are your thoughts about poly thread used in cotton quilts. Some are saying nay, and some say go for it.

I like the idea of all cotton, but it can be linty in the machine. I like the sheen of the poly, but was told it can rip the cotton material over time.

What's your thoughts?

I say go for it. I think the "poly cutting cotton" has been labeled a myth, or at least deemed to be outdated information if it ever was true. I think it's very common for longarmers to use poly. And honestly, on all of the old quilts I've seen, it's the faces of the cotton fabric pieces that wear out well before the seams do. The fabric inside the seams is protected, after all. I don't think you need to worry about it.

Personally I don't like the poly sheen, but I have found low-sheen poly threads that I will use in my quilts! So far the quilt police haven't arrested me. :)

I personally love polyester for piecing because it's fine and less lint. I use it in my sit down machine too if I want the thread to fade more into the quilt and not have thread build up when travelling to a new spot. I think 40 wt is usually too thick for my taste.

I'd suggest you read up (or watch videos) on the Superior Threads website. There's a TON of info there. The ripping of poly thread is a long-debunked myth. That is what used to happen with old threads but does not with the modern threads.

What does your dealer mean by "use 40 wt"? For piecing 40 wt is WAY too thick. I generally piece with 50 wt and many piece with 60 wt. FMQ is OK with 40 and even thicker if you want to see the quilting pattern.

As for fiber content, it really is personal preference. I have used linty cotton and clean poly. As long as you clean the machine when using cotton there is no benefit or drawback.

I use 40 wt Aurifil cotton thread on my longarm, but also use poly. Aurifil is expensive and I only have about 6 different colors so I can afford more colors in poly.

I've always used what my Gammil dealer recommended and have never had any tension problems or unsatisfied customers. I got my machine in 2004. Thread is A&E, 40 weight both in the bobbin and top. I buy it by the large cone but have seen it in a smaller cone as well.
I've used Aurfil for piecing for years and years.

As long as you can get the tension adjusted properly and control your speed Appropriately you can pretty much use whatever thread you want. I’ve used 100 wt thread in my sweet sixteen and 30 wt thread. Poly sometimes and cotton sometimes. But sometimes I really have to work with the tension adjustments.

It's a good idea to experiment.

I started out with King Tut, which I believe is a 40wt cotton thread. It was okay, but I didn't like the lint and I did get occasional breakage. Then I tried Glide, a 40wt polyester thread. Glide gave me much less lint to clean, no breakage, and I liked the little bit of shine it gave to my quilts.

Recently I tried Bottom Line, a 60wt polyester thread, in both top and bobbin and fell in love! My quilting looks sooooo much better! The silver color is supposed to blend in with everything, and I am loving that color too.

Liked the Bottom Line so much, I ordered Superior's 100wt monoquilter thread to try out. But for now, think I will stick with Bottom Line for awhile.

I agree with others that these days polyester is perfectly fine to use in quilts. It is not going to rip the cotton material over time. I prefer cotton thread for piecing (Aurifil 50wt) for a couple of reasons, one of which is that it is more "clingy" and so does not slip out of my stitches when I am chain piecing and cutting between pieces. However, for frame quilting, I much prefer polyester thread. I believe 40wt cotton thread was the gold standard for many years before polyester threads improved so much. People have a tendency to stick with what works for them, so your advice may be coming from someone who is old school that way. Nothing wrong with old school, but nothing wrong with new school either.

Most machines do well with a wide variety of types and weights of thread. Some do not like a particular thread. Experimenting yourself is the best way to find out what your machine likes and what you yourself like. I only wish I had tried out the Bottom Line before I bought so many cones of Glide!

I can honestly say that the local quilt shop only uses polyester thread for everything.

I have come to use Arifil 50 Wt. cotton thread almost exclusively. It is NEVER linty and has a nice sheen to it - unless I need a specific color for piecing (e.g., a gray I recently used), I use Arifil 2000 -a "light sand." If you look it up at Amazon, you will see what a nice sheen it has. It is just wonderful thread! If you check out the reviews of this thread, I think you will understand why so many like it.