It would appear this technique dates back about 2300 before Jésus-Christ.
The Egyptian paintings show goldsmiths making gold leaves.
A detail of of a gilded column
Fleuron of a chimney screen
which is gilded.
From 1700 before Jésus-Christ, one discovered a mean to hammer gold in order to obtain
very fine leaves capable to adhere on a glitter surface. Phoenician, Chinese and
Egyptian used this method.
The Byzantines used a lot this technique for icons and mosaics. At the mediaval epoch,
leaf gilding has been used for illuminations. The Baroque epoch also liked it enormously.
Today, one manages to produce gold leaves about one micron of thickness. To obtain
it, one must place a ribbon of metal between two sheepskins or intestines of ox.
Some paving-stones and special hammers are used in order to reduce shocks imparted
to workers and buildings.
During this process, it's necessary to dry the wet traces thanks to an hot iron.
Gold is dusted with talc in order to the leaf not be glue to the sheepskin. This
technique hasn't changed at the present.
It existed two different processes to cover with gold leaves, the water gilding and
oil gilding. Cenino Cennini talked about these one in 1437 in his "libro dell'arte".
Two centuries later, it's the "traité de laquage et de vernissage" from Stalker and
Parker which mentioned it.