It's generally a silversmith's finish. It's sort of 'traditional'
for the insides of silver goblets. I've got a couple of pieces that
were gold washed on my website.
It's the insides of the goblets. It gives a nice contrast, and a
wonderful fiery glow to the insides of the bowls.
As I understood it from the plater, it's just a thin 24K gold. Not a
full-on thick plate, just a thin 'wash' of gold. I had one of those
done in London, and one in the US, so platers on both sides of the
pond are familiar with the idea, but I picked up the habit from my
silversmithing tutor in London.
It's thin, so I'm not sure it'd survive enameling, but it'd be one
way to get around some of those nasty 'enamel-hates-silver'
Actually, now that I think of it, both of those goblets are
sterling, so there's no nickel or copper strike under the gold, it's
just gold- on-silver, which is what you'd need to have a hope of it
not blowing up during enameling. (Nickel or copper would react at
temp. Not good.) Methinks that what they're actually meaning by
'wash' is just gold over silver, with no strike layers under it.
That being said, a simple way to get the same effect without needing
to find a plater would be to kum-boo the silver enamel piece. Kum-
boo's a Korean technique much written about in the Orchid archives,
that lets you weld thin foils of gold down onto silver pieces. Much
thicker than any plate, thus more likely to survive repeated firings
without diffusing into nothing.
For whatever that all's worth.