Trying to figure out the production method for hotstamped chips. Is this how it works: a metallic foil sheet placed over the chip(s), then stamping die embeds the stamp with pressure & heat? Since some gold hotstamps wear down to silver color, does this mean that the foil sheet is 2-ply -- gold over silver? (Yes, I know hot stamps come in silver, red, blue, etc. too, but I'm referring to the most common gold hot stamps.)

Is the metallic foil just gold-colored, or is is real gold (precious metal) foil, like gold leaf?

Inquiring minds want to know.