Hul Tytus fired this volley in
:

You might search via google for "electro less" plating. This is,
reportedly, a misnomer that referes to a non external electrical
process. Copper and nickel varieties, and I believe I've heard
reference to gold types, exist.

It's not so much of a misnomer. "Electro-less" plating has to do with
the molecular affinity of certain salts for surfaces which are of a
different dielectric charge. No current flows, only molecular and atomic
attractions are at work to cause the deposition of metals or salts on the
surfaces.

The most common way to plate plastics is to apply a very mildly-
conductive coating of a metal salt by means of an electro-less "seeding"
process. After that, first vanishingly small, then greater currents are
drawn in a plating solution to cause real metal to be deposited upon the
surface. Usually, that first plating is a more base metal like copper or
tin. After a suitable layer of the base is there, it is polished, and
then the precious metal is plated over that by normal means.

Someone with a little chemistry skills could "mirror" a surface with a
silver deposition solution similar to what is sometimes used to
(actually) "silver" mirrors. Then the silver can be used as the first
conductive base layer.

If you scrape nearly any metal-plated plastic item (like trim on cars),
you'll see a copper layer beneath the chromium.

Lloyd