A metal leaf, also called composition leaf or schlagmetal, is a thin
foil used for
gilding
Gilding is a decorative technique for applying a very thin coating of gold over solid surfaces such as metal (most common), wood, porcelain, or stone. A gilded object is also described as "gilt". Where metal is gilded, the metal below was trad ...
and other forms of decoration. Metal leaves can come in many different shades. Some metal leaves may look like
gold leaf
Gold leaf is gold that has been hammered into thin sheets (usually around 0.1 µm thick) by goldbeating and is often used for gilding. Gold leaf is available in a wide variety of karats and shades. The most commonly used gold is 22-karat ...
but do not contain any real gold. This type of metal leaf is often referred to as imitation leaf.
Metal leaves are usually made of
gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile ...
(including many alloys),
silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
,
copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish ...
,
aluminium
Aluminium (aluminum in AmE, American and CanE, Canadian English) is a chemical element with the Symbol (chemistry), symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately o ...
,
brass
Brass is an alloy of copper (Cu) and zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a substitutional alloy: atoms of the two constituents may replace each other wit ...
(sometimes called "
Dutch metal" typically 85% Copper and 15%
zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic t ...
) or
palladium, sometimes also
platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver".
Pla ...
.
Vark is a type of silver leaf used for decoration in Indian cuisine.
Goldbeating, the technique of producing metal leaves, has been known for more than 5,000 years. A small gold nugget 5 mm in diameter can be expanded to about 20,000 times its initial surface through hammering, producing a gold foil surface of about one half square meter with a thickness of 0.2–0.3
μm
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...
.
Nanjing gold leaf forging technique
History
This is a traditional handicraft in
Nanjing
Nanjing (; , Mandarin pronunciation: ), Postal Map Romanization, alternately romanized as Nanking, is the capital of Jiangsu Provinces of China, province of the China, People's Republic of China. It is a sub-provincial city, a megacity, and t ...
, produced as early as the
Three Kingdoms
The Three Kingdoms () from 220 to 280 AD was the tripartite division of China among the dynastic states of Cao Wei, Shu Han, and Eastern Wu. The Three Kingdoms period was preceded by the Han dynasty#Eastern Han, Eastern Han dynasty and wa ...
and Two Jin Dynasties; it was used in Buddha statue manufacturing and construction. It was widely used in the gilding of Buddha statues and idols and the construction industry during the Eastern Wu and
Eastern Jin Dynasties.
During the Qing Dynasty, (1640-1912) the technology developed, and Nanjing gold leaf was sold overseas. It retains traditional
smelting
Smelting is a process of applying heat to ore, to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a ...
, hand-beating and other techniques, and the gold leaf is pure, uniform and soft. On May 20, 2006, it was included in the first batch of national intangible cultural heritage representative items.
Modern gold leaf artists combine ancient traditional crafts with modern technology to make traditional gold leaf. Forging skills are more sophisticated.
Nanjing Gold foil forging technology.
The gold foil production in
Nanjing
Nanjing (; , Mandarin pronunciation: ), Postal Map Romanization, alternately romanized as Nanking, is the capital of Jiangsu Provinces of China, province of the China, People's Republic of China. It is a sub-provincial city, a megacity, and t ...
follows the ancient production process. The forging process has been tempered by more than a dozen processes such as gold bar, leaf beat, twisting, opening, assembly, issuing, and foil cutting. It is also called "playing gold leaf." According to the needs of different products, a proportion of silver and copper is added; the metal is then melted into liquid, poured into an iron tank and cooled to form gold bars, hammered into thin slices, cut into small gold pieces, and then covered with gold foil and hammered into gold foil repeatedly at high temperature.
Gallery of gold leaf
File:goldleaf.jpg, 22k gold leaf applied with an ox hair brush during the process of gilding
Gilding is a decorative technique for applying a very thin coating of gold over solid surfaces such as metal (most common), wood, porcelain, or stone. A gilded object is also described as "gilt". Where metal is gilded, the metal below was trad ...
File:Small gold nugget 5mm dia and corresponding foil surface of half sq meter.jpg, A 5 mm gold nugget beaten to a one half square meter square of foil
File:burnishing.jpg, Burnishing gold leaf with an agate stone tool during the water gilding process
See also
*
Professional Picture Framers Association
References
{{reflist
Gold
Visual arts materials