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Thanks guys. Heathfield, At first glance all I get are references to electroplating - this is not what I saw on TV - see below. Whickerman, no, that is exactly the point, what was demonstrated was swabbed onto the surface (any non-absorbent material, as I remember it). Electroplating is the standard (including industrial) method and not the least bit exceptional or difficult to understand - you just need the bath and electodes, etc. but not something you contemplate as a one-off or just out of curiosity.