Which undercoat for gold paint?

Another experiment on cardboard.

The display stand for the Enterprise-C calls for a gold coat. My question was whether to prime it first with a light or a dark undercoat. Black primer has the disadvantage of requiring more layers of topcoat to get complete coverage, but it covers the model a lot faster.

I coated a piece of cardboard one half with white primer and the other half with black. Using the airbrush without pulling the trigger helps you dry the paint a lot faster, so you don't have to wait several hours for the coat to dry. After thinning the gold paint to the right consistency for spraying, I sprayed both the white and the black part.

The result on the white part was a very white-ish gold sheen. On the black part it was a deep-dark gold cover which - for me - is the more desirable effect.

More experimenting with different colours will teach me which colours are best supported by black primer instead of white or grey. I might even learn it doesn't make any difference, although I do suspect that painting a white Enterprise will be difficult on a black undercoat ...