I guess I should have said 'how old' the quilt is that I have with thread but fabric torn at the stitching lines. That quilt was made by my DH's aunt around 1940 and I'm not sure it is polyester thread.... not even sure that polyester thread was available to sewers at that time. And, I could cut out some of the thread and give it a flame test to see if it is man-made fiber but don't want to do any more damage to the quilt.

I did check the Clothide (I think that's correct) site about their thread information and found this quote:

Fiber: Try to match thread fiber to fabric fiber. Cotton fabric should be sewn with cotton thread; polyester or manmade fiber should be sewn with polyester thread. If possible, don't sew natural fibers with polyester thread. Polyester fiber is stronger than most natural thread, so over time, the stronger polyester thread can break the weaker cotton fiber of the fabric. For quilting, look for thread labeled "machine quilting" or "hand quilting."

So, polyester thread is available to all of us today.... I just don't buy any of it for quilting due to its strength. It is still okay for polyester fabric.... but I don't buy any of that....don't like the feel. There are still plenty of those iron-strong quilts made back in the 1960's from polyester knits..... really don't like those but I hear they are warm and wear like nothing else.

Nanna

Hello and welcome to the board. I do a lot of raw-edge appliqué and as the others have said, it's up to you what you use and what effect you're trying to achieve.
Some like their appliqué to blend in, so use a cotton that exactly matches their piece. Others like a little emphasis on their hard work so use a rayon or polyester.
There are whole articles about what thread to use - some will tell you cotton, some silk and some will say rayon.... Others believe that a trilobal polyester is better than rayon if you like a sheen on your work.
Possibly not the definitive answer you were hoping for, but happy appliquéing! :)

Part of the problem with some of the older quilts, is that they were made from used clothing. In many cases, that fabric was already quite worn, thus weaker than the thread, to begin with.

Totally agree with this. You can use any type of thread and any color you like. And I don't buy into the philosophy that polyester thread cuts fabrics. JMHO.

I did some online research awhile ago on threads and found that silk thread (at least sometimes) deteriorates faster than other thread. One quilter said that she had appliqued a quilt seven years previously, had used both silk and cotton thread, and was having to repair all the patches she had sewn with the silk thread.

I do a fair amount of applique, and I use 60 w cotton thread, in an off white/lt. tan. I use the ladder stitch, and my stitches don't show.

I usually hand stitch appliques on and I have used DMC thread 2-3 strands.

I really like Aurifil because it's cotton and only 2 ply so it blends in well with the applique. I was taught to use cotton and was told about this thread being good for it and since I use it more for piecing than any other thread I tried it and it works so well. Very strong thread; lots of colors to chose from

I mostly use cotton thread, often the embroidery weight(60) and the brand I have most of is DMC. I have used silk, and find the few colors I have blend with just about everything. I also have used Mettler 50 weight as that is the thread I have the most colors of.

You did not say what type of applique you are doing. Hand or machine, raw edged or turned? My fav is raw edged and decorative stitches and using fusible to hold it all in place. I go through my stash of thread and pick what ever I think will look best. Love the machine embroidery thread for this - it shines!

I know how to do hand applique - but like others on here - getting the arthritis in the old hands. But, remember, there's no stress on the applique like there is on seams in clothing. Your quilt, your call. We are all "artists" here so be creative.