Series editors' preface - Wood Tools

ethical considerations. Objects that have survived
with their original gilding intact usually
have significant historical, and often monetary,
value. Many gilding conservators prefer inpainting
to in-gilding. If in-gilding is deemed
necessary for the interpretation of the object, it
should be reversible without damage to original
material and clearly delineated from it. This
consideration may rule out the use of traditional
materials that are identical to the original
in composition and solubility.
As is the case with other decorated surfaces,
the conservation of gilded surfaces is often
complicated by past restoration treatments of
an object. Some areas may have been overcleaned
and then coated with bronze powder
paint, whilst other areas may have been
regilded or left untouched. The appearance of
the object may have been unified by the application
of a pigmented toning coat. Any decisions
about cleaning, consolidation or aesthetic
reintegration depend on identifying the gilding
type and the stratigraphy of the surface decoration.
Although a trained eye can usually distinguish
oil and water gilding, there are
occasions when it can be difficult to distinguish
the two. Generally speaking, oil gilding is
matte, often laid onto a yellow, white or cream
layer, and may be found on furniture, frames,
architectural mouldings, metal objects, lettering
and exterior decoration (Halahan, 1991). It can
be swollen by aromatic hydrocarbons such as
xylene and toluene, is usually soluble in polar
solvents such as alcohol or acetone and will be
completely removed by strongly polar solvents
such as dichloromethane. Water gilding is
often burnished, may be laid onto a coloured
bole and is limited to interior decoration. It can
be found on picture frames, furniture and
sculpture. Water gilding is soluble in aqueous
cleaning solutions and may be damaged by
organic solvents characterized by a degree of
hydrogen bonding. Polar solvents that have no
hydrogen bonding such as dichloromethane
can be used on water gilding as they present a
low risk of damage to the surface.
Clues about previous treatments may be
offered by the overall appearance of the object
– whether the carving appears clogged by
gesso added during previous restorations,
whether the wood substrate is a species typically
found under gilding or whether there are
traces of earlier or different surfaces. Analytical
Conserving other materials II 771
techniques such as examination under UV, low
power magnification, visible light and fluorescence
microscopy or thin layer chromatography
can also be utilized to characterize gilded
surfaces, assess whether the object was originally
gilded and whether more than one layer
of gilding is present. Microscopy can assist in
understanding the condition and extent of any
original layer/s (see, for example, Powell,
1999). The information gained from visual and
technical examination of a surface should be
used to identify goals and formulate an appropriate
treatment. Consolidation and cleaning
are generally the first treatment steps following
examination.
16.9.2 General care
Gilded wood is susceptible to significant and
sometimes irreversible damage as a result of
excessively high, low or repeated cycling of
RH extremes. Robertson (1991) recommended
aiming for a temperature around 60–70 °F
(15–22 °C) and a relative humidity of 45–55%.
Water gilding can be damaged by moisture
from hands, flower vases, spraying of flowers,
spilt drinks or condensation on the base of
drinking glasses. Oil gilding can be damaged
by spilt solvents or alcoholic drinks (Halahan,
1991). Gilded frames should not be hung
against an exterior wall, above a radiator or air
conditioning outlet. As with all light-sensitive
objects, gilded furniture should not be placed
in direct sunlight. Although the gold leaf itself
is photo-chemically stable, exposure to light
will accelerate the deterioration of any coatings
on the surface of the gold and localized heat
can affect the gesso underneath.
16.9.3 Cleaning
Preventive conservation is the most important
part of keeping an object in good condition.
Giltwood objects can be dusted with a sable
brush and the dust removed with a low suction
vacuum cleaner with gauze over the nozzle to
avoid the loss of any loose flakes. The use of
feather dusters or loosely woven cloth should
be avoided. If a cloth is used it must be
absolutely clean, lint-free, soft and smooth and
should not be used for any other cleaning tasks.
Before undertaking a cleaning treatment, it is
essential to identify areas of water gilding, oil