Watch this short (3:45) documentary film by Andrea Mariotti – lusciously visual and musical – about gold leaf production in Florence, Italy. This is an old artisan technique still used, but slowly dying out. You can see the gold ignot being prepared and rolled to create super fine gold leaf, used in the case for decorative gilding and frame restoration. In jewelry, a similar 22-24k gold foil can be applied to fine silver with a permanent heat-fused bond with an ancient Korean technique called Keum-boo.
Gold 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. 22-karat yellow gold is the most commonly used.
Gold leaf is sometimes confused with metal leaf but they are different products. The term metal leaf is normally used for thin sheets of metal of any color that do not contain any real Karat gold. 24 Karats is pure gold. Real yellow gold leaf is about 92% pure gold. Silver colored white gold is approximately 50% pure gold.
Layering gold leaf over a surface is called gold leafing or gilding. Traditional water gilding is the most difficult and highly regarded form of gold leafing. It has remained virtually unchanged for hundreds of years and is still done by hand. A gold nugget of 5 mm in diameter can be expanded through hammering into a gold foil of about 0.5 square meter.
Gold leaf has traditionally been most popular and most common in its use as gilding material for decoration of art (including statues) or the picture frames that are often used to hold or decorate paintings, mixed media, small objects (including jewelry) and paper art. “Gold” frames made without leafing are also available for a considerably smaller price, but traditionally some form of gold or metal leaf was preferred when possible and gold leafed (or silver leafed) moulding is still commonly available from many of the companies that produce commercially-available moulding for use as picture frames.