My second experiment:
I tried a different fabric. That white fabric feels like a poly/cotton but it isn't. A softer cotton is easier to quilt.
The hearts were an experiment with the bobbin and feed dogs. The first group is feed dogs up and bobbin thread just through the tension clip in the bobbin case. The second group is feed dogs down. Then for the next group I threaded the bobbin thread through the eye in the bobbin case as well as the tension thingy. Bernina machines (and some others) have an eye on the bobbin case. The first six hearts are done with the feed dogs down and then I put them back up. I think the quilting is smoother on the third group.
This is another idea that I was exploring. It's an untied celtic knot!
And this is just a doodle - but it was fun to do it.