Look at the light bulb quilting right next to those loose wavy lines....one is totally flattening the fabric and the other has lots of space. They are very high contrast which works for my mini. I don't normally do light bulbs so dense and after this quilt I definitely won't do it again this small! You can't even tell what they are, so what's the point?
Here is the bubble filler. It works for such a small space.
And here's a closeup of the curves. This photo is actually larger than in real life. Not bad for no marking!
Density is something I think about when planning a quilting design. Less dense areas tend to show up more when the rest of the quilt is quilted densely which is what I tend to do.
I hope you get to quilt today!