jitkaau

If it is good quality polyester or cotton, either would be suitable to quilt with. However, I prefer good cotton on good cotton quilts as it is my belief that it goes through the material more smoothly than other fibres. It also washes and irons in much the same way and so you don't have to pay extra care because of the thread you have used. I use every weight from 12 to 60 on my quilts as I like decorating them. The only time I use the rayon is for embroidered sections, but not to quilt.

mommessy

I've been using YLI silk thread for machine quilting...works really well and is not so heavy. Love it.

nancylouie

i also have the pfaff grand quilter and have used signature thread and have good luck with that. It is a 40 wt and comes 3000 yards/cone. i ues the same on the top and bottom. king tut has worked well also using thread on the same on the top and bottom. i purchased signature online and the cones are less expensive that king tut.

soccertxi

for machine quilting, my go-to threads are Permacore and Omni. Omni is a poly wrapped cotton just like the perma core ( or is that cotton wrapped poly?). Any how, I like them both. They are not very heavy..and not too thin. the Omni is a new line from Superior Threads and has a bit more of a sheen. They come in scads of colors. Permacore is a bit cheaper.