To map and understand degradation of art objects, researchers sometimes have to zoom in down to the square micrometer. A new infrared technique provides even more detail.

For almost five centuries, the colored statues of saints have been in Mechelen among all kind of relics and other objects in a richly decorated, paradisiacal garden, which can be closed with painted panels. In the 16th century, the Augustinian nuns made these retable cabinets, known as ‘Enclosed Gardens’. A unique religious art form for which the sisters used a variety of materials such as metal, glass, bone, coral and amber. Many of these parts suffered from material decay over the centuries, but the brass elements in particular, in the form of sequins and threads, seemed to have stood the test of time surprisingly well. It was therefore remarkable that some sequins and wires did show obvious corrosion.

As part of a larger research project on the manufacture and preservation of the Enclosed Gardens, chemist Andrea Marchetti, a researcher at the University of Antwerp’s A-Sense Lab, looked into this problem with his colleagues. ‘The Enclosed Gardens, located in the nuns monastic cells, have always been in the same indoor climate. Yet, there was a difference in the state of conservation‘, Marchetti says. ‘We then started looking at the microenvironment. We had a suspicion that the possible