Heirloom Gold Leaf Studio
A Brief Introduction to Gilding

Gilding, the application of a thin layer of gold upon the surface of an object,
dates back to the ancient Egyptian and Chinese cultures. It was not until the
Renaissance,however, that Italian artisans introduced the first prototype of the
water-gilt picture frame in the form of altar pieces for religious icons. Over the
past six hundred years, the process of water-gilding has remained virtually
unchanged. Even in today's world of technological advances, if a proper gilt
frame is to be produced, the vast majority of the labor must be undertaken solely
by hand.           
Because of the amount of hand-craft involved in the production of these
frames, they remain in a different class than standard manufactured and
pre-finished mouldings. This difference is reflected in appearance, quality, and
price. Unlike machine-made frames and even some "museum frames" mass
produced by larger concerns, the gilt frames produced in our studio are
individual pieces, art works in and of themselves, and they do not depreciate but
rather accrue value over the years; because they are crafted individually, they can
be customized exclusively for the artwork they surround.
The first step in producing a water-gilt frame is the construction of the wooden
sub-frame which serves as the foundation for the layers of gesso, clay, and gold.
When constructing the wooden frame, it is important to create sturdy miter
joints that can handle the rigors of the gilding process. A unique feature to the
frames made in our studio is the wood-on-wood joinery employed in the miters.   
Unlike nails or pins, the interlocking spline and dowel joints will not rust or
work their way free as the frame expands and contracts.
After the wooden frame has been constructed, it is prepared for the gesso
coating by first being sealed with an emulsion of thinned rabbit-skin glue; this
seals the pores of the wood and raises the grain to provide a firm seat for the
gesso. The gesso itself is a mixture of calcium chalk and glue, several coats of
which are applied to the wooden frame.
Once the gesso is dry it must then be polished to a smooth, glassy surface with
great pains taken to eliminate imperfections and redefine any contours or
carvings that have become subdued by the gesso coat. After a satisfactory
surface has been achieved, the gesso is ready to receive the clay, also known as
the bole.
The clay mixture is similar to the gesso, only its composition is somewhat softer
than that of the gesso. This softness is necessary so that the clay will "give"
slightly under the pressure of the burnishing agate, a smooth, polished stone
used for polishing the gold onto the surface of the clay.
 Because of the slight transparency of gold leaf, the color of the clay plays an
integral role in the overall tone of the frame. Red clay gives the gold a fiery
warmth and accentuates the warm colors and flesh tones in a piece of artwork,
lending an air of intimacy, whereas blue clay imparts a sense of coolness and
distance to the finished piece. It is important to consider the effect the bole color
will have on the framed work.
After the clay has been mixed to its proper consistency, it is applied to the gesso
until sufficient coverage is achieved, usually two to five coats. It is then allowed
to fully dry. Once dry, the clay is then polished like the gesso to a smooth, hard
gloss, as free of imperfections as possible. After this polishing, the frame is
ready for gilding.
The laying of the gold is the most difficult and challenging aspect of producing a
gold leaf frame. The gold comes in leaves that are 3 3/8 inches square and
approximately 1/250,000th of an inch thick. These leaves must be handled with
dexterity and care, using only a gilder's tip (a wide, thin brush) to pick up and
apply the gold to the clay surface.
To apply the gold, the gilder must wet an area of the frame surface with a
mixture of water and alcohol; this reactivates the glue in the bole. The gold is
then floated on top of this water solution. As the solution is absorbed into the
clay, the gold adheres to the surface.
After the gilding is completed, the frame is allowed to dry until it reaches its
burnishing point. It is crucial to burnish the gold while the clay is still somewhat
damp, as a dry bole can cause the gold to scratch or chip under the pressure of
the agate.
When burnishing, the gilder uses smoothly polished agate stones that are
attached to wooden handles. These agates are available in a variety of shapes and
sizes which correspond to the different contours of the frame's profile. The agate
is firmly run along the surface of the leaf, giving it the mirror-polished look of
freshly minted gold. After burnishing, the frame is allowed to fully dry before
any final finishing is undertaken.
The options for finishing a gilded frame are numerous. The simplest treatment
is, of course, no treatment at all - this being modern clean gold. However, even
with modern gold, it is often desirable to give the frame a toning color wash in
order to unify the frame with the piece and also to soften the hard look of
brightly burnished gold. Another option is "distressing," which includes
anything from a slight rub to expose the bole, to actually beating up the frame
with various tools to give the effect of age and wear. After heavy distressing, the
surface is usually given an antique color wash and a coating of rottenstone
(decomposed limestone) to simulate the crusty deposits of time.
 Finally, one must decide whether or not to seal the gold. While covering the
gilded surface with a clear coat of shellac will make the gold less susceptible to
damage, and in the case of white or pale gold will prevent tarnishing, it also has
the effect of slightly diminishing the natural brilliance of the gold. An unsealed
22 karat gold leaf frame will stay beautiful as long as it receives proper care and
handling and will, over time, acquire its own patina.
 One must be careful to avoid touching the surface of an unsealed gold leaf
frame, and it should only be dusted occasionally with a very soft brush or cloth.
Liquid cleaners must never be used on any gold leaf surface, as they can destroy
it immediately.
When given the care and respect accorded to any fine furnishing, the frames
crafted in our studio will give lasting beauty to generations and are certain to
become treasured heirlooms to those who acquire them.
                                                                                    - Rick Eddy
Links for additional information
on gilding:

water-gilding video clip

Building conservation/ gilding article

Picture Framing Magazine/ gilding archives

Society of Gilders/ gilding information