I use any brand polyester, cotton wrapped polyester, cotton, old cotton thread, any size - any weight cotton thread in my machines, and while making quilts, with each other throughout the quilt piecing. Any color mixture also, most times my bobbin and top thread do not match either. Some times though when I feel the quilt police breathing down my neck, I only use aurifil, or connecting threads with matching bobbins, but that feeling doesn't last too long, especially when the bobbin runs out.