Gold Leaf Gilding & Other Gilding Variants- Part II
Oil gilding is a process that is less complicated and less time consuming. The wood surface is prepared and made smooth with gesso or other coatings, smoothed and then well sealed. A very thin layer of a special oil varnish size or other adhesive size is brushed on top of the sealed surface and in a specified amount of time this will dry to a sight tackiness. The leaf is then laid over the whole sized surface and tamped onto the size to produce a uniform surface covered in leaf. The oil gilding process can be used for all types of gold, silver and metal leaf. This method is nearly always used to apply the heavier leaf varieties such as brass, copper and aluminum because of the stronger adhesive qualities needed to adhere them to the surface. Although these thicker types of leaf can be water gilded and burnished this is rarely done. The result is not as bright as when using precious leaf.
When some areas of an object are gilded and others areas are left without gilding it is known as partial gilding.
Some other techniques that can also be referred to as gilding do not use gold or metal leaf. One is known as Roman gilding or burnish bronze gilding which uses finely ground brass or bronze powders which are available in many different colors. One way to apply the powders is to mix them with a glue binder and brush the mixture on top of the prepared bole surface. This can be burnished with an agate tipped burnisher to a somewhat muted sheen. Another variant of this is known as flash gilding which uses either a mordant size or animal glue size onto which the brass powder is sprinkled and held by the adhesive.
Finally, gold paint applied can be applied to a surface but this should not really be considered gilding at all but is sometimes mistaken for it by the untrained eye . Gold paint is made from brass powder mixed into a medium that is brushed or sprayed on. The surface will have a coarser appearance than a true leafed surface and will usually tarnish and discolor as it ages and oxidizes.
The allure and beauty of gold are ages old and an understanding of the techniques and materials used in the gilding arts can only further the appreciation of these ancient processes.