Thanks I thought so. Initially I was really upset that it kept breaking then realized my lamp cord was catching on thread and caused it to snag.

I'm hoping my quilts get used & loved & worn out, leaving wonderful memories.
Use what ever thread you want.

my thread kept shredding and i ck'd. it was poly on poly. Coats and clark. thought it was cotton. used to always be. sigh. anyway it works fine in bobbin. so cotton on top always.

Coats & Clark has many threads available.

The "old" Dual Duty was cotton covered polyester.

The 'new" Dual Duty thread is polyester covered polyester.

omg---
i've been quilting with poly thread for years.

it is beautiful-
lots of thread companies carry wonderful poly quilting threads-

don't be narrow minded- you miss out on so much when you are not willing to try new things- if it wasn't ok to use- there would not be this HUGE market---
quilters quilt with lots of different threads- poly, rayon, nylon, wool, metallics, silk....and even cotton threads....make beautiful quilts that stand the test of time

Rayon is weak, so don't use it to quilt with, or on quilts that will be used and washed. I prefer to use 100% cotton for quilting, but will sometimes use poly embroidery thread to machine applique with. Honestly, there are so many beautiful cotton threads on the market I've never had to use poly to quilt with. I save that for machine embroidery.

The reason you were given for not using poly thread is no longer a valid reason. It is "old wive's tales" so to speak If I may use that expression. The thread is a personal preference and what works for you and your machine. "It won't hold up for a 100 years" is laughable now a days.

True story here: One of my favorite pictures of my hubby as a boy is one of him with a big smile; however, he is wearing the ugliest plaid, polyester pants ever made. He is about 6 y.o. in the picture, so I'm guessing it to be 1973-ish. Just a few years ago (think 2007-ish!), my in-law's septic system had some issues and they ended up replacing the plumbing line from the house to the tank several yards away. When they dug up the line, they discovered, in the dirt, several feet below the earth's surface, the above-mentioned ugly plaid polyester pants! My mother-in-law washed them up and gave them to me (still not sure why!). I must admit, though, they were and are still in mint condition! Polyester v. cotton? Hmmmm.

Some of it has to do with shrinkage. If you pre-wash your quilting fabric it doesn't "squish" up as much after quilting when washed. Cotton thread will shrink up a smidge, too, and polyester won't...

I was using cotton thread up until a while ago. I was frustrated with shredding, breaking etc.
I don't know whether it was because the thread changed or my sewing technique changed.
Anyway, I tried Isocord on my last quilt and loved it.
I finished the whole quilt with NO thread breakage. The other thing I really liked is it's thickness. It blends right into the fabric, and a spool/bobbin lasts forever! Less bobbin changes for me is a good thing :)