Gold leaf, often referred to as gold foil in the context of certain applications, is a material used in the decoration and gilding of objects, including furniture. It consists of extremely thin sheets of gold that are beaten down or hammered into delicate layers. Here's a detailed description of gold foils when applied to furniture:

Composition: Gold leaf is traditionally made from 22 to 24 karat gold, which is alloyed with small amounts of other metals such as silver and copper to make it more malleable and durable for application. These leaves can vary in thickness but are generally around 0.1 to 0.125 micrometers thin, which is less than the thickness of a human hair.

Manufacturing Process: The process of creating gold leaf is meticulous and labor-intensive. A small amount of gold is rolled out and repeatedly hammered until it is expanded into an ultra-thin sheet. This is often done using a process that has been handed down through generations of skilled artisans. The final sheets of gold are so thin that they become semi-transparent.

Application: Gold leaf is applied to furniture through a process called gilding. The surface of the furniture is usually prepared with a base layer called 'gesso' (a mixture of plaster and glue) and then coated with an adhesive material known as 'size.' When the size becomes tacky, the delicate gold leaf is laid onto the surface with a special brush known as a gilder's tip. It is a painstaking process that requires precision and care to ensure a smooth application without tearing the delicate metal.

: After the gold leaf is applied, it is often burnished with a tool to give it a smooth, lustrous finish. To protect the gold leaf and prevent it from tarnishing, a sealant can be applied. This also helps to keep it adhered to the furniture surface.