Electromagnetic Diagnostic Techniques for the Conservation of Modern Oil Paintings: A Review

Modern oil paintings are characterized by the extensive use of industrial pigments, synthetic binders, and chemical additives introduced during the late nineteenth and twentieth centuries. While these innovations enabled significant artistic experimentation, they also introduced new conservation challenges due to the chemical instability of many modern paint formulations. As a consequence, modern oil paintings frequently exhibit degradation phenomena such as efflorescence, yellowing, blistering, peeling and cracking, and high sensitivity to water and organic solvents. A comprehensive understanding of the materials used in modern oil paintings—including pigments, binders, and additives—is therefore essential for developing effective conservation strategies. In this context, electromagnetic (EM) diagnostic techniques represent powerful tools for the noninvasive or minimally invasive investigation of artworks. These techniques allow researchers to characterize the chemical composition, morphology, and degradation processes affecting paint layers and substrates. This paper provides an overview of the EM techniques most commonly used in the conservation of modern oil paintings. Particular attention is devoted to spectroscopic and imaging methods such as scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, UV-Vis spectroscopy, and X-ray-based techniques, as well as to the laser technique for the delicate cleaning process. Through selected case studies reported in the literature, this review highlights the role of these techniques in pigment identification, degradation analysis, and the development of more effective conservation strategies for modern oil paintings.