X-ray fluorescence analysis in the study of paintings – an overview

Energy dispersive X-ray fluorescence analysis (EDXRF) is an excellent method in investigations of cultural heritage treasures, including easel and wall paintings and illuminations in ancient manuscripts. As one of the few methods applicable for this purpose, it is non-destructive and non-invasive. It is often combined with other methods such as optical microscopy, visible light photography, UV fluorescence photography, infrared reflectography, Fourier transform infrared spectroscopy, X-ray radiography, Raman spectrometry and others. The complex layered structure and mixtures of pigments, especially on easel paintings, represent a challenging task from the point of view of analysis. However, without taking samples it is only possible to analyse the thin surface layer of the investigated object with a thickness of tens to a few hundreds of micrometres. Nevertheless, this is not too much a problem when analysing paintings and even more so in the analysis of illuminations in manuscripts. The paper has an overview character and aims to summarise the possibilities, advantages and problems of XRF in this area and to demonstrate them on selected examples of published works, which in some cases are devoted to the works of leading painters from various historical periods (Giotto di Bondone, Antonello da Messina, Raffaelo Sanzio, Antonio Allegri da Corregio, Anthonis van Dyck, Rembrandt van Rijn, Giorgio Marini, Pablo Picasso and others). This review includes also a brief mention of selected research carried out in our laboratory.