I am doing a lot of FMQ at present, on my special bedding, and I am using the project to practise new stitches. Without thinking on the second one I used the same bobbin thread as the top, wrong...... not looking at the pattern as it is my first attempt but at the stitching you can see the uneven tension and knots :thumbdown:
Compare that to the one that I use the bobbin thread you can see why I will be using the bottom line thread from now on.