I use C&C Dual Duty or All Purpose for most piecing. For quilting, I use C&C but I have to put sewer's aid on it and I have had several cones that I pitched due to breakage or knots. I have used and love Robison-Anton 50 wt cotton machine quilting thread & Sulky Blendables 30 weight. I also have some King Tut but haven't used it yet. I prefer pre-filled, 60 wt poly bobbins for piecing & quilting.