Goldbeating
Encyclopedia
Goldbeating is the process of hammering gold
into an extremely thin unbroken sheet for use in gilding
.
artisans recognized the extraordinary durability and malleability of gold and became the first goldbeaters and gilders. They pounded gold using a round stone to create the thinnest leaf
possible. Except for the introduction of a cast iron
hammer
and a few other innovations, the tools and techniques have remained virtually unchanged for thousands of years.
intestine
membrane (Goldbeater's skin
) was used to interleave the gold as it was beaten. Today other materials, such as Mylar, are used. Using wooden pincers, the preparer picks up each square of gold and places it in the center of each skin. When the cutch is filled with the small gold squares, it is wrapped in several bands of parchment
which serve to hold the packet together during the beating. Parchment is still the best material known to withstand the hours of repeated hammer blows needed to beat the gold.
The gold is beaten on a large, heavy block of marble
or granite
. These stone blocks were sometimes placed on top of a tree trunk set deep into the ground. This created greater resiliency for the hammer. Beating of the cutch by hand takes about one hour using a fifteen pound hammer. The goldbeater instinctively follows a pattern and sets up a rhythm, striking the packet with up to seventy strokes a minute. The packet is rotated and turned over to ensure that the gold inside expands evenly in all directions. The original small squares of gold are beaten until they have expanded to the outer edges of the four inch square cutch. The gold is taken out of the cutch and each piece is cut into four pieces with a knife. Using the pincers, these squares of gold are put into a second packet called the shoder, which has approximately 1,500 skins. The shoder is beaten for about three hours until the gold has expanded to a five inch square.
powder. This process is called briming, and it prevents the delicate gold leaf from sticking to the skins. The mold is beaten with an eight-pound hammer for three to four hours until it has been beaten into a circle about six inches in diameter. The finished leaf forms an unbroken sheet of gold with a thickness of 1/250,000 of an inch. After the leaves are taken out of the mold, they are conventionally cut into a three and three-eight inch square and packaged in tissue-paper books containing twenty-five leaves.
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
into an extremely thin unbroken sheet for use in gilding
Gilding
The term gilding covers a number of decorative techniques for applying fine gold leaf or powder to solid surfaces such as wood, stone, or metal to give a thin coating of gold. A gilded object is described as "gilt"...
.
History
5,000 years ago, EgyptianAncient Egypt
Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...
artisans recognized the extraordinary durability and malleability of gold and became the first goldbeaters and gilders. They pounded gold using a round stone to create the thinnest leaf
Gold leaf
right|thumb|250px|[[Burnishing]] gold leaf with an [[agate]] stone tool, during the water gilding processGold leaf is gold that has been hammered into extremely thin sheets and is often used for gilding. Gold leaf is available in a wide variety of karats and shades...
possible. Except for the introduction of a cast iron
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
hammer
Hammer
A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head,...
and a few other innovations, the tools and techniques have remained virtually unchanged for thousands of years.
Rolling
The karat and color of leaf varies depending the amount of silver or copper added to the gold. Most goldbeaters make 23karat leaf. The gold and its alloy are put in a crucible and melted in a furnace. The liquid gold is poured into a mold to cast it into a bar. The bar of gold is put through a rolling mill repeatedly. The rollers are adjusted each time to make the gold thinner and thinner. The bar is rolled to 1/1000 of an inch thick many times longer.Beating
After rolling, the ribbon of gold is cut into one-inch squares. The first step in the beating process is called the cutch. The cutch is made up of approximately 150 skins. In the early days of the trade, oxOx
An ox , also known as a bullock in Australia, New Zealand and India, is a bovine trained as a draft animal. Oxen are commonly castrated adult male cattle; castration makes the animals more tractable...
intestine
Intestine
In human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
membrane (Goldbeater's skin
Goldbeater's skin
Goldbeater's skin — the outer membrane of calf's intestine — is a parchment traditionally used in the process of making gold leaf by beating, reducing gold into mere 1μm-thick leaves....
) was used to interleave the gold as it was beaten. Today other materials, such as Mylar, are used. Using wooden pincers, the preparer picks up each square of gold and places it in the center of each skin. When the cutch is filled with the small gold squares, it is wrapped in several bands of parchment
Parchment
Parchment is a thin material made from calfskin, sheepskin or goatskin, often split. Its most common use was as a material for writing on, for documents, notes, or the pages of a book, codex or manuscript. It is distinct from leather in that parchment is limed but not tanned; therefore, it is very...
which serve to hold the packet together during the beating. Parchment is still the best material known to withstand the hours of repeated hammer blows needed to beat the gold.
The gold is beaten on a large, heavy block of marble
Marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite.Geologists use the term "marble" to refer to metamorphosed limestone; however stonemasons use the term more broadly to encompass unmetamorphosed limestone.Marble is commonly used for...
or granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
. These stone blocks were sometimes placed on top of a tree trunk set deep into the ground. This created greater resiliency for the hammer. Beating of the cutch by hand takes about one hour using a fifteen pound hammer. The goldbeater instinctively follows a pattern and sets up a rhythm, striking the packet with up to seventy strokes a minute. The packet is rotated and turned over to ensure that the gold inside expands evenly in all directions. The original small squares of gold are beaten until they have expanded to the outer edges of the four inch square cutch. The gold is taken out of the cutch and each piece is cut into four pieces with a knife. Using the pincers, these squares of gold are put into a second packet called the shoder, which has approximately 1,500 skins. The shoder is beaten for about three hours until the gold has expanded to a five inch square.
Packaging
The gold is taken out of the shoder and placed on a leather-covered surface. The gold is thin enough now that the cutter can simply blow on it to flatten it out. Using a wooden implement called a wagon, the gold is quickly cut into four pieces and immediately placed in a packet called a mold for the final beating.The wagon has sharp cutting blades, traditionally made from malacca cane. The mold contains 1,500 pieces of gold. Before the mold is filled with gold, the skins are coated with a gypsumGypsum
Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...
powder. This process is called briming, and it prevents the delicate gold leaf from sticking to the skins. The mold is beaten with an eight-pound hammer for three to four hours until it has been beaten into a circle about six inches in diameter. The finished leaf forms an unbroken sheet of gold with a thickness of 1/250,000 of an inch. After the leaves are taken out of the mold, they are conventionally cut into a three and three-eight inch square and packaged in tissue-paper books containing twenty-five leaves.
External links
- Gold Beating sections from 1903 American Library Edition Of Workshop Receipts Vol5 by Ernest Spon
- Goldschlägerstadt Schwabach (in German) partly illustrated history of goldbeating