In order to characterise an art object such as a sculpture or a candlestick, it is important to identify precisely the materials of which it is made. For example, a plaster sculpture is often the one that was used to make the mould for the same bronze sculpture. In this article, we will show and explain the different materials that should not be confused, such as patinated plaster and bronze, gilded stucco and gilded bronze for example.
Bronze, brass, regula and copper
It is important to know these metals, which are often confused when it comes to differentiating between them.
Bronze is an alloy of copper and tin. Bronze sculptures are very strong, which guarantees them a certain longevity. Oxidation gives bronze its characteristic "verdigris" colour.
Brass is a metal comparable to gold because it has a beautiful golden colour. It is widely used in cabinet making to decorate furniture. Its oxidation gives a colour similar to that of bronze. Brass and bronze can be differentiated by comparing their weight, brass being much lighter.
Regula is an alloy that appeared at the end of the 19th century and consists of tin and antimony. The advantage of regal is that it does not use copper and is therefore cheaper than bronze.
Copper is used in the manufacture of bronze. However, it is much redder, even when the bronze is composed of more copper than tin.
plaster, wax and stoneware
As with metals, other materials are used in art, plaster or wax sculptures were often ephemeral models, serving only to make the mould into which the bronze was cast.
Plaster is made from gypsum. It is liquid when mixed with water and dries very quickly. It is therefore easy to make sculptures from a mould. When plaster has a patina, it can be mistaken for other materials.
Wax is smooth to the touch and is a ductile material that sculptors can easily shape. However, wax cracks as it dries, so it is very rare to see old wax art objects.
Stoneware is made from stoneware clay which is ground into a powder and then into a mouldable paste. When fired (between 1200 and 1300°C), it takes on a colour that varies between brown and grey-green. Fired stoneware objects are very strong. A glaze can be applied to the stoneware before firing, which gives it a smooth and shiny appearance.