Gilding Arts Newsletter

Once a surface such as a picture frame, architectural element, or a section of furniture has been water gilded, the object may be considered complete: fully gilded, burnished and modern in it's untouched brilliance. However, there are a number of treatments that a gilder can offer that will alter the appearance of the gilding, from very subtle to drastic, depending upon what is being asked for.

Shades of gold leaf range anywhere from 6.4kt white gold to pure 24kt with many in-between. An object gilded with genuine gold leaf of 22kt or higher does not need to be protected from tarnishing. When gold leaf tarnishes, it's the silver or copper content that oxidizes, having been combined with gold to create a particular shade.

Gold leaf lower than 22kt can therefore show signs of oxidization and becomes more susceptible the lower the karat due to the higher presence of silver or copper. A protective coating is often added to gilding and becomes necessary if the leaf used is lower than 22kt; otherwise, the silver or copper will turn in color over time, usually brown to black.

There are a variety of clear topcoats that can be used to protect gilding although anything placed over gold or silver leaf will change its appearance. Special care must also be taken when choosing a topcoat for an oil gilded object, as the protective coating must be compatible with the oil size used in gilding, otherwise an interaction may occur. This is mainly a concern with the use of lacquer which, if painted or sprayed over the gilding, the surface will quickly crackle under the 'heat' of the lacquer. It's possible to first use an isolating coat of clear shellac which acts as a barrier between the oil gilded leaf and the lacquer.

Shellac is also a very good choice of a topcoat for use in both oil gilding and traditional water gilding. It tends to reduce the reflection of the brilliant shine of the gold and can impart an attractive warmth. When dry, buffing with rottenstone on cheesecloth will reduce the glossiness of the shellac and help 'marry' the final finish.

Shellac is also best when made fresh from Blonde dewaxed Shellac flakes (or Ruby if additional color is desired) and ethyl alcohol. Denatured alcohol may also be used but its scent is stronger due to the added toxins. Always use the appropriate mask and gloves from the effects of the alcohol.

Another topcoat application that is very useful for some water gilding projects is the application of a 5:1 ratio of 10% RSG solution to distilled water. The weak rabbit skin glue helps to protect water gilded gold leaf that is left matt and does not have the benefit of burnishing which compresses the gold leaf into the surface as well as imparting a bright burnish. Leaving some sections of a gilded object in its original non-burnished state offers contrast to the burnished sections. However, it is more vulnerable to wear and so the 5:1 solution can provide some protection. Once dry, the object may be left 'as is' if 22kt or higher was used, or a thin coat of shellac can be applied for additional protection or simply for the warming affects of shellac.

To prepare the 5:1 solution, simply use a portion of the glue from the the jar of Full Strength Rabbit Skin Glue that was used to prepare the gesso, or make a fresh batch by combining 1 part RSG granules to 9 parts distilled water. Let soak for four hours and then heat until completely dissolved. Remember, do not heat the glue any hotter than 120 degrees F to avoid spoiling the adhesive quality of the glue. You may then mix 1 part of the dissolved glue to 5 parts distilled water or store the glue in the refrigerator for later preparation. Use a soft bristle brush such as Kolinsky Sable to apply the weak RSG solution.

These are the beginning steps for completing a water gilded surface which will provide a modern, solidly gilded object. In our next issue we will take an indepth look at creating antiqued finishes to lend the quality of age to a gilded frame or other object.