Authentic antique bronzes are considered to be those sculptures made from the original moulds or maquettes and cast by the licensed foundries in the lifetime and with the agreement of the artist or posthumously authorised by the artist’s heirs. Aside from the many nuances that can only truly be learnt through years of handling antiques, there are some clear indications relating to materials and processes in which inauthentic bronze sculptures will likely deviate from authentic antique sculpture. Here are some tips of what to look out for.
The Art of Chasing
Once a bronze sculpture has been cast and cooled the rod/sprue marks are chased and re-detailed by hand. Any scars left by the rods are carefully blended to match the rest of the surface. The skilled chaser will painstakingly add the detail to the sculpture’s surface as intended by the artist; this process is quite individual to each sculptor, similar to the brush strokes that may be recognised in a painter’s work. The overall quality of the surface detail helps determine both age and authenticity: as chasing the surface of bronze to achieve fine detail is a difficult, time-consuming and costly process, there are fewer and fewer specialists who can achieve quality hand-chasing and much of this work is now done by machine. The resulting surface is generally either too smooth or has mechanical lines made by electric drills that cannot replicate the beauty and care taken when using a handheld chisel and punch.
The Importance of Patination of Bronze Sculpture
Following chasing, a patina is applied to the surface of the bronze to change its colour. This is done both to protect the surface of the raw bronze, which would otherwise oxidise over time, and to enhance the overall aesthetic effect.
There are two types of patina. Chemical patinas affect the surface of the bronze, causing a colour change by either oxidation or acidity, and give the surface a wonderful ‘warm’ feel that accentuates the realism of the subject. Painted patinas use artists’ pigments; these can be more intense in colour than chemical patinas and, as they sit on the surface of the bronze, can wear away more easily.
Chemical patinas look different to painted patinas because the surface is not simply covered but rather intrinsically altered. Just as with antique furniture, these patinas will wear down beautifully over the years in quite unique ways and become part of the history of a bronze sculpture. As it is very difficult to fake this aged patina, it is one of the important factors to consider when judging authenticity.
Depth of Colour as a Guide to Authenticity
The mix of alloy used in antique bronze captures an underlying, beautiful pink colour, illustrating the large amounts of copper present. This is very different to the cheaper bronze alloys used today that include an abundance of silicone. The chemical patination that is applied to modern recasts results in a thinner, more ‘watered down’ colour on the surface with a silvery/grey undertone.
The cold painted colours that are used today are also quite different in tone and texture to those found on antiques, as they have not had time to age and undergo the natural wear that comes with handling, atmosphere and time.
The Colour of the Base
Many sculptures, especially Art Deco bronze sculptures of the 20th Century, were placed on marble or onyx bases, which served to protect the furniture from the bronzes’ coarse edges and also gave the figures more height and importance.
Importantly, the quarries that were mined for marble and onyx during the early 20th Century mostly closed down before and during the Second World War. The colours of the wonderful bases from this period are very prominent in their depth and quality, in contrast to the less deep colours produced from modern quarries, and can therefore indicate the age of a sculpture. It is also worth noting that an authentic antique bronze sculpture with a replacement modern base that has been spuriously signed is no longer considered to be authentic.
The Dimensions
Bronze expands when heated and contracts when cooled, with the contraction resulting in shrinkage in size by between 2% and 3%. If you can obtain exact information of the dimensions of an original bronze you can compare the pieces to determine whether your piece is an original cast or a re-cast.
David Hickmet
Hickmet Fine Arts
www.hickmet.com
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