By far the greater bulk of let­ter­press work in gold is pro­duced by bronz­ing, and the res­ults obtained by this method are excel­lent.

The pro­cess involves, first, print­ing the sheet in a tacky medium such as bronze pre­par­a­tion and then dust­ing it with bronze powder which adheres to the pre­par­a­tion.

It is then lightly burn­ished to smooth and brighten the bronze and then the loose bronze is cleaned off the sheet.

Small work can be bronzed by hand, but the work must be car­ried out under vacuum.

Bronz­ing machines have been avail­able for a period of years.

During the 1960s  if you did any bronzing whatsoever you had to drink a pint of milk a day (paid for by the Boss).

What the milk had in it to neutralise any bronze powder in the air I will never know.

Then in the early 1970s some bright spark said we would have to start drinking a bottle of Coca Cola a day.

Now that did make me feel worse.

via Gold Ink, Bronzing and Foil Printing | British Letterpress.