Exploratory Analytical Study of a 20th century Portuguese Mural Painting by Julio Resende (1917-2011)

Abstract

This paper unveils for the first time the technical and material features of the mural painting entitled Pentecost’s, executed by the Portuguese artist Julio Resende in 1955. The painting depicting twelve Apostles covers the altarpiece of a small church in the countryside of Évora (southern Portugal) and it was rediscovered in 2013 by art historians. The research was carried out with both non-invasive and micro-destructive techniques. In situ examination included technical photography in visible (Vis/Vis-RAK) and in infrared (NIR) light range, ultraviolet induced visible fluorescence (UVF), portable optical microscopy, visible spectrophotometry and handheld energy dispersive X-ray fluorescence spectroscopy (hXRF). Further analysis on paint layers micro-samples were undertaken by dark field optical microscopy (OM), scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM-EDS) and micro-Fourier transform infrared spectroscopy (μ-FTIR). According to the acquired data, the mural was executed in a fresco technique (true and most likely lime fresco). Full size cartoons and handmade sketches were used for transferring the composition to the wall. No traces of organic binder were found with the analytical setup and the analysis of paint layers revealed the use of cobalt blue, a wide range of ochres, chromium green, green earth and barium white. The use of chrome orange and cadmium-based pigments are hypothesized.