Testing, learning. It’s there just need to find the correct combo
For some reason I have a feeling that doing the image on a larger scale will be beneficial to improving the end results (due to more area to smooth the gradient over). What size are each of these tests? Look to be about an inch square. I’d go with 2 inches square to give double the resolution.
Actually, for testing purposes it might be better to test on something soft too, like balsa wood or soap even.
Definitely agree that testing it bigger will make it easier to dial in your settings.