use a rolling mill - much more controlled, with some effort
you can get the gold to within about 0.002" of the thickness you
Also - it seems that if you rolled 3 layers at once, the center
layer would be protected from contamination.
Jerry - a sputter target is the source of ionized gold plasma atoms
for "sputter-coating" non-conductive materials to make them
conductive - you blast the target with high-velocity argon atoms to
vaporize the metal. Non-metallic specimens for scanning electron
microscopy have to be coated this way; it also is what makes "aqua
aura" quartz crystals blue, believe it or not. Has to be done in a
high-purity high-vacuum environment.