I believe Scott used gold on most of his brandywine jobs though he'd know better than me....;-)
I just fininshed a set of skins using a silver pearl under the wine.With gold the flame will look more blood red, and with silver they will have more of a purple or violet color to them.
In a no light environment the flame will be unseen making the job look like a solid black paint but as soon as the light hits it..WAMMO!!
the flames appear.Pretty awesome look.
I sprayed an intercoat clear between flames and base mainly as a protection incase I needed to redo or remove the artwork(flames).
As I'm sure everyone else here does the same. Better to reshoot some flames than repaint the base and all.Plus the intercoat is alot easier to tape on and pull off.