French eighteenth-century painting techniques

Abstract

Recent conservation treatment of several eighteenth-century French paintings at the J. Paul Getty Museum and the Los Angeles County Museum of Art allowed the authors to examine French painting techniques from this period more closely. The paintings proved to have unexpectedly complex layer structures that were revealed initially in the examination of paint cross-sections. Thin, non-pigmented, fluorescent layers were found isolating double grounds and paint layers. Polarized light microscopy and fluorescing stains were helpful in determining the nature of some of these layers. Additional examination using Fourier transform infrared spectrometry (FTIR) and gas-chromatography/massspectrometry (GC-MS) identified the media used by the artists. Energy dispersive X-ray microanalysis (SEM-EDX), electron-probe microanalysis and X-ray fluorescence (XRF) identified the pigments in the multiple paint layers. These findings are discussed in connection with relevant seventeenth- and eighteenth-century lectures and treatises.