Patent gold leaf, also referred to as transfer leaf, is gold mounted to special tissue paper by a pressure process. A book of patent gold leaf is assembled by placing each unit of gold leaf and tissue between pieces of thin rouged paper. The gilder can then remove one leaf at a time without distributing the remaining leaves. Patent gold leaf is removed from the book without the aid of a gilder's tip. The leaf will stay on the tissue until it is pressed onto the prepared surface and the tissue backing is removed. This form of gold leaf is necessary for outdoor work or where conditions would make loose leaf unmanageable. Patent gold leaf is not suitable for water gilding and is best suited for flat surfaces.
Patent gold leaf is sensitive to changes in temperature and humidity and needs to be stored properly. Store patent leaf in a damp environment of about 80% humidity wrapped in plastic wrap. This helps to prevent the moisture content of the tissue paper from fluctuating. Patent leaf may become loose on the tissue paper if stored in a dry warm environment. To correct this problem, the book of patent leaf needs to be stored in a humid environment under pressure to "remount" the leaf to the paper. If the leaf were stored in a very hot and humid environment, the leaf may adhere too tightly to the paper. To correct this problem, store the patent leaf in a refrigerator or a dry cool place.
Surface gold leaf may have a few irregularities and is often used where double gilding is required or the leaf will be distressed or toned.
This term refers to the average thickness which a manufacturer has deemed as the standard for gold leaf. This standard may vary from one manufacturer to another. One gold beater's regular may be thinner than the regular leaf of another brand.
Double gold does not mean that the leaf is two times thicker than regular leaf. Double leaf may be only 10% to 20% thicker than regular gold leaf. Double means that it is heavier than regular.
This term applies to gold leaf which is selected for its higher quality having fewer pinholes or other irregularities.
Karats and Alloys
Gold is alloyed with silver, copper and other metals to achieve a variety of colors and shades. A higher gold content and/or greater amount of copper will result in deeper tones of leaf. The higher karat leaves are also more durable due to the higher gold content. In the lower karats of leaf, such as 18kt, 16kt and 12kt, gold is alloyed with silver or other metals to achieve lighter colors.
Gold Leaf for Exterior Projects
Gilded building details made from wood, stone, fiberglass and metal take on the dynamic qualitites of gold - it's luster and color. The correct selection of gold leaf, its gold content and thickness, will ensure a long lasting gilded ornament.
Gold leaf is manufactured in a wide range of colors and karats. Leaf made from 100% gold is 24 karat leaf. To produce of variety of colors, copper and silver is mixed with gold. When copper is added, the leaf becomes warmer and richer in tone. When silver is added, the leaf becomes paler in tone. The addition of these other metals lowers the karat value of gold leaf. Gold leaf is manufactured in a range from 6 kt "White" to 24 kt "Fine Gold". Gold is completely resistant to corrosion. The addition of silver and copper lowers the resistance of gold leaf to corrosion. However, the copper or silver in 23 kt or 23.75 kt leaf is so low that it will maintain its integrity outdoors for 30 years or more. A dome, building detail or outdoor statue will require a 23kt to 23.75 kt leaf that ranges from 96% to 98.5% in purity. Karats less than 23 are recommended for indoor use and many colors and karats are available.
Leaf Thickness and Weight
Leaf thickness is best described as grams per 1,000 leaves. This measurement is used to compare one variety with another. The appropriate weight of leaf for an outdoor surface is 18 to 23 grams per 1,000 leaves. The heavier the leaf, the longer it will repel the abrasive effects of snow, rain, wind, dust and sand particles. When selecting gold leaf for an exterior architectural project, look first for the gold content and gram weight. A 23 kt to 23.75 kt gold leaf weighing 18-24 grams/1000 leaves properly applied will shine for decades on your next architectural gilding project.
Please call SeppLeaf Products at 212-683-2840 to special order various leaf thicknesses and weights.