A Brief History of Gold Leaf Sign Making
Gold leaf is gold that has been hammered into extremely thin sheets and is often used for gilding. In the sign making industry gold leaf is used to finish carved letters. It can also be used on glass, this technique is knows as glass gilding. Gold leaf is available in a wide variety of karats and shades. 22-karat yellow gold is the most commonly used. Alternatively there are other leaf metals available for use, such as palladium, white gold, and aluminum.
The application of gold leaf, known as gilding, is an ancient art which is currently experiencing a revival. Gilding services are now in high demand. Despite it’s long history the actual techniques and applications have never changed. In days past one would learn this craft through apprenticeship with a master gilder. This is still common today as the knowledge is passed down from one sign maker to the next.
Types of Gold Leaf & Alternative Metals
Leaf of every kind is supplied in books, each of which contains 25 sheets. 500 books to a pack. Each sheet measures 3 and 3/8 inch square. The thickness of gold leaf can be as low as .0000035 inches. Some alternative metals such as aluminum are less expensive. Because of this the sheets can be as large as 5 and one half inches square and somewhat thicker that gold. There are many different type of gold leaf available:
XX Gold (23 karat) – This gold also know as deep gold is commonly used for glass gilding an surface gilding. Lemon Gold (18 karat), Pale Gold (16-Karat), and White Gold (12-karat); these alternative shades of gold leaf can also be used for glass gilding and surface gilding on carved signs. Silver Leaf is available but it is not something we use because it tends to tarnish quickly. Palladium Leaf and aluminum serve as a great alternative to silver. Also many types of white gold will due if they are white enough to resemble silver. We also use variegated leaf which is made of copper alloy. The material is oxidized to create random colorful patterns and blends. Variegate leaf can be red, green, blue, and purple.
Gold Leaf Application Methods
Glass Gilding is the process of applying gold to glass. The gold is backed up with black backup paint and varnish. There are so many different creative ways to apply gold to glass. For the sake of expedience and price we usually apply double gold (XX Gold), two layers on size directly to the glass. Size is just water with a pinch of gelatin. The water can be heated slightly to allow the gelatin to dissolve quickly. The size must return to room temperature because it can be sprayed onto or brushed onto the glass. Sheets of gold leaf are applied to the glass immediately after the size. After the size dries the gold leaf can be polished with a cotton ball and then additional layers of size and gold leaf can be a applied. The outline and shadow can be applied before or after the gold leaf is applied. This depends on whatever method the gilder is comfortable with. The backup paint can be applied by hand or it can be screenprinted. Backing up the gold with paint and varnish is the last part of the process. Once all your paint is dry one must eradicate the excess gold. It can be removed by hand with a soft brush.