And I should have left plain, white, well-enough alone.
And THEN I invested many hours of my life creating this pattern on the fabric.
Then, I broke the lamp I had done all this work for. And I did not want to waste all the effort. So, I watched a couple of videos online about how to cover a plain shade with fabric.
And it turned out thus:
The good news is that this failure did not cost me anything but my time. And I learned a couple things, so the time was not completely wasted.