You CAN use Quilting Thread in your machine - but not a good idea if you are piecing. Since Quilting Thread is thicker it can add too much bulk to your seams. The thread you want to avaoid in your machine is Hand Quilting Thread- this is the thread that is coated and will mess up a machine. There are lots of great Quilting Threads out there (including King Tut) that work great for doing your actual quilting on your machine. Hope this helps!