Coloring materials and technical recipes in the mural paintings of the Hermitage of “Mas de Tous” (La Pobla de Vallbona, Valencia). Physicochemical and cultural study

The painters who worked in the Europe of the late nineteenth century and the beginning of the twentieth century had to synthesize in their works very different materials and artistic techniques. Pigments that had a long tradition, such as hematite (Fe₂O₃) or carbon black, were used together with the new coloring materials that appeared between the 18^th and 19^th centuries, such as cobalt blue, also named Blue Thénard (CoO.Al₂O₃), or ultramarine artificial blue Na_6-10Al₆Si₆O₂₄S_2-4 (approximately) (Plesters 2002:55).The colors of organic origin, and especially those from the plant world, were also used in this period for its physical and luminous properties, in accordance with previous studies on Contemporary Art. This was the case, for example, of many Valencian painters, such as José Benlliure, Ignacio Pinazo, Salvador Abril, Antonio Muñoz Degrain or Joaquín Sorolla, among others. The physicochemical study of four pictorial panels preserved at the Hermitage of “Mas de Tous” (La Pobla de Vallbona), and dated in this period, has revealed important data to contribute to the understanding of Contemporary Valencian painting. Moreover, the technical study has allowed identifying some similarities and differences with the work of other Contemporary Valencian painters, as relevant as Joaquín Sorolla. The physicochemical techniques that have been used for this purpose in the Laboratory of Analysis and Diagnosis of Work of Art of the Universitat de València, and the Scientific Park of the same institution, have been the Optical Microscopy (LM), the Scanning Electron Microscopy- X-ray microanalysis (SEM-EDX) or Fourier Transform Infrared Spectroscopy (FTIR), among others, such as visible spectrophotometry (UV-vis) or Raman Spectroscopy (RMS).