The frame holds an undistinguished landscape painting of the Tuscan hills, painted by a Chicago amateur in the 1920s, and the painting has nothing much to recommend it. The frame, however, is a fine American example of nineteenth-century water-gilded composition work, probably from a Boston frame shop around 1885, and it is worth several times more than the painting it surrounds.
The current owner is a young architect named Felicity Cordray, who inherited the painting and frame from her great-aunt and hung the whole assemblage in the entrance hall of her apartment in Chicago's Andersonville neighborhood. She wrote to The Pewter in early April with a question: how do you clean a gilded frame.
The short answer is that you barely do. The slightly longer answer is the subject of this piece.
The first thing to understand about a gilded frame is what kind of gilding it has. There are three principal techniques, and the differences matter for cleaning.
Water gilding is the oldest and finest. Real gold leaf is applied over a layer of red or yellow bole — a fine clay slip — which itself sits over a layer of gesso applied to a wood or composition substrate. The bole is moistened with water at the moment of application, and the gold leaf is laid onto the wet bole, where it adheres by surface tension. The result is a brilliant, slightly translucent gold surface that can be burnished to a mirror finish with an agate tool.
Oil gilding is the workhorse technique. Gold leaf is laid onto a tacky oil-based size and pressed into place. The result is duller than water gilding, somewhat more durable, and cannot be burnished.
Gilt paint — bronze powder mixed with a binder — is not gilding at all. It is paint that looks vaguely like gold for the first ten years and then tarnishes to a dull brown. A great many decorative frames sold as gilded are actually gilt-painted. Tell the difference by looking at the high points: real gold remains gold; bronze paint tarnishes unevenly and is duller in the recesses.
Cordray's frame, examined under a strong light with a 10x loupe, was water-gilded, with a red bole visible at the corners where decades of handling had worn through the gold. The gold itself was thin — water-gilding usually is — and in places it had been touched up at some point in the past with a poorly matched gilt paint.
This is, in fact, the typical state of a nineteenth-century gilded frame that has been in continuous domestic use. Original gilding in the recesses and on most of the moldings, wear at the corners and high points down to the red bole, and one or more layers of well-meant amateur touch-up paint somewhere on the surface.
The conservator's first principle of gilded-frame cleaning is to do nothing that touches the gold. The gold leaf on a water-gilded frame is, after a century and a half, perhaps three or four millionths of an inch thick. It can be removed by a damp cloth, a fingertip, or in extreme cases by an unwary breath.
What can be removed safely is the dust that has accumulated on the frame. Dust on a gilded surface, left in place for decades, eventually becomes a faint grey film that dulls the gold. The film can be removed without touching the gold itself if the right tools are used.
The right tool is a soft natural-bristle brush. Conservators use Japanese hake brushes, made of soft goat hair, in widths from one inch to three inches. A clean watercolor brush of the same materials, never used for paint, will also do. A makeup brush, soft and unused, has been recommended by more than one conservator in print and works as well.
The technique is to brush, very lightly, in the direction of the ornamental relief. The bristles touch the dust but never bear weight on the gold. Each pass of the brush is followed by a gentle puff of air — from a hand bulb of the kind used for camera lenses, never from compressed air in a can — to clear the lifted dust away.
A canister vacuum, set to its lowest suction, can be held a few inches above the frame with a soft brush attachment to capture the dust as it lifts. Some conservators use a piece of muslin stretched across the nozzle as an additional filter, in case a fragment of gilding does come loose during the cleaning.
The whole operation, for a frame of the size Cordray owns — about thirty inches by twenty-four — takes perhaps fifteen minutes if done carefully. It should be done once a year, in the spring, when the heating season is over and dust accumulation has been at its peak.
What should never be done is the application of any wet substance. Water dissolves the bole beneath water gilding and lifts the gold with it. Solvents dissolve the size beneath oil gilding and lift the gold with it. Polishes, waxes, oils, and proprietary frame cleaners are, almost without exception, harmful to original gilding.
If a frame is grimy beyond what a brush can address — if it has been in a smoking household, for example, and the nicotine film is heavy — the only responsible course is to consult a conservator. The technique for removing such films involves dilute aqueous solutions, fine cotton swabs, and a great deal of training, and it is not a household project.
Cordray's frame, when she sent a follow-up photograph in early May, looked considerably brighter than it had in her original image. She had spent an hour with a clean watercolor brush, working slowly across the relief, and had been startled to find that the gold was still as bright as it was when she swept the brush over it.
The bole-showing corners and the old gilt-paint touch-ups remained as they were. She had been advised to leave them. A frame conservator working in Evanston, whom she had consulted on a separate matter, told her that the corners were honest evidence of the frame's use, and the amateur touch-ups, however poorly matched, were part of the object's history as a household possession.
The painting still hangs in her entrance hall. It is still not a very good painting. The frame, however, is a fine object, and it is now, modestly, looked after.
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