Beginning from the antique literature, production and coating methods of leaf gilding on metals and non-metals are discussed. Already after a relatively short time since introduction of this gilding method, thin foils of only a few microns thickness were produced and applied to various base materials. Our investigations on a gold foil from a Roman marble column yield interesting information on the preparation methods of the base material and the structure of the gold layer. Fire gilding, in which a gold-mercury paste is applied onto a metallic base and, after evaporation of the mercury by heating, the remaining gold layer is densified by mechanical polishing, is first observed at about the 4th century B.C. in various areas of the Mediterranean and ancient China. The different transitions from leaf-to mercury-gilding are discussed. Our investigations on pieces of the gold layer of an alamannic fibula give information on the various steps of the mercury-gilding process. -- CAL