I use invisible thread on top and cotton or polyester in the bobbin. I use it to stitch in the ditch to anchor a quilt top to the batting and backing before I do FMQ (free motion quilting).
My Bernina Activa sews best with it when I put the spool in a little jar beside the machine and run the thread through a hole in the side of an empty bobbin that I put on the thread spindle. Before I did it this way, the thread would tangle or get caught on something.