I use the quilting thread for piecing and some quilting on my old singer. I haven't used it in my new machine. Cottin is fine for piecing too. I think I even have some quilts pieced with polly. But I like the quilting thread. It's stronger.
JMO
If you are talking about piecing, then polyester thread is fine. If you are talking about doing the actual quilting, then I like to use quilting cotton thread, but polyester is also fine.
Just be careful when you buy cotton for quilting. If you plan to quilt on the machine, make sure it is suitable, because you can get cottons for hand quilting, which are waxed, and they will just mess up your machine.
I'm glad you made this clarification. Someone tried to sell me some hand quilting thread for machine quilting. I did not buy it. Thanks bunches.
I really don't know anything about quilting, but here is a * and bump back to the top.