Micro X-ray diffraction for painting and pigment analysis

Micro-X-ray diffraction (Micro-XRD) offers many opportunities for non-destructive, in situ crystalline phase composition analysis of varied artworks. This paper discusses the application of this technique to paintings. Painting surfaces and cross-sections can be examined to characterise pigments and provide additional information complementary to existing investigative analyses, which often rely only on elemental information. This study was completed in three parts: proprietary tube paints were examined showing differences in pigment composition on the basis of paint quality; analysis of cross-sections from Tiepolo’s Banquet of Cleopatra provided information on ground layer composition; and a small panel painting was examined non-destructively by placement within the instrument. Through these examples the utility and versatility of the technique is demonstrated.