Why don't you make a bunch of test plates so that you can arrive at a sideplate colour that you see as consistent? As an aside, I want to see how Ziggenhahn arrives at Essencia colors. Very curious about that process.
I've noticed consistent colors around specific parts of engraving patterns. Like the rose bouquet surrounded by greys segueing to blues. Suggests the plates are blocked not just for warpage, but to direct color as well.
I enjoy your work and am happy to see your progress.
Keep it up!
Looking forward to seeing your next displays.
CZ