Page 340 - Copper and Bronze in Art: Corrosion, Colorants, Getty Museum Conservation, By David Scott

ial or exposure, and the concomitant difficulty of sorting out which corrosive event is due
to which period in the object's life. This complexity of events adds interest to the discussion of
patina since in some cases it is impossible to know what an object's original appearance was
intended to be. Recent research has added fresh insights into this difficult subject.
Patinas can be naturally occurring, such as the smooth, attractive surface that develops on
bronzes over time, or they can be artificially created by the deliberate treatment of an object's
surface to create a colored layer, a copper compound, or an intentional corrosion product that
may be formed before burial.
The attractive nature of colored copper surfaces was already well appreciated in antiquity.
Plutarch, for example, writes in his Mor alia:

[A] number of visitors to the sanctuary of Apollo at Delphi are made to discuss the
question whether the patina on the bronze group in front of which they are standing is
natural or artificial. One of them is admiring the beautiful surface of the bronze, which
resembles neither dirt nor rust, but looks as f it had been dipped in a bath of brilliant
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blue colour. I wonder whether the ancient masters used a certain mixture or preparation on
their bronzes? 1

C H A N C I N G V I E W S OF BRONZE PATINAS

One still unresolved question is whether the ancients artificially patinated their bronzes or kept
them bright and polished. In 1915 Richter evaluated the available evidence and concluded that
the majority of bronzes must have been kept polished and golden in color. Indeed, the golden
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color of bronze, as opposed to the reddish hues of copper, must surely have been appreciated in
the endless search for gold and golden-colored surfaces that played such a prominent role in the
technology of both the Old and New Worlds. As Richter observes:

It is a curious anomaly that nowadays we cover many of our bronzes with an artificial dark­
ish tone, and thus obtain artificially a patina similar in appearance to that produced by
nature on ancient specimens. For the Greeks and Romans themselves, to judge by what evi­
dence we have, kept their bronzes in their original color, and thereby had the double advan­
tage of a rich golden tone and a beautiful play of reflected lights on the surface. (Richter
1915 : xxvii-xxviii)

To support her thesis, Richter notes that a number of utensils and implements, which could
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only have served their purpose f kept bright and clean, are now covered in exactly the same
patina as statuettes and other decorative objects. Some bronzes are decorated with niello, silver,
copper, or paint; and the aesthetic effect of this decoration would have depended on these areas
being contrasted with shiny bronze metal.

S O M E A S P E C T S O F B R O N Z E PATINAS
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