Caring for Composite Materials

Works of art that are made from a mixture of materials can often be more problematic than works of art made from one material. This is because each kind of material has different needs if it is to be kept at its most beautiful and safe from harm for as long as possible. When these different kinds of materials are put together, the choices of where to display them become more limited and great care must be taken in looking after them.

The Side Table is an example of a composite object that is very difficult to look after. This table combines wood, metal and turtleshell, all of which need looking after in different ways. Wood and turtleshell (which are organic materials) are affected by different levels of humidity so are best kept at a constant 55% relative humidity so that they don’t dry out and crack. This high level of humidity can be bad for brass, which is a metal, because it can speed up oxidation, which makes the brass darken. Also, brass expands in heat, so is best kept at a constant temperature of 20°C.

The delicate pieces of brass and turtleshell that form the marquetry decoration on the Side Table have been glued in place. Over time, however, glue can fail and pieces can come loose. Conservators (people who care for the objects) try to use traditional methods to glue pieces back in place. They also try to understand the ways in which objects can become damaged and then work out how to stop this happening.