Ana García Bueno

Mortars, pigments and binding media of wall paintings in the ‘Carrera del Darro’ in Granada, Spain

Abstract The Carrera del Darro is a street within the city of Granada, Spain, which is emblematic owing to the architectural value of its buildings, to its significance for the urban structure of the city and to the implications it has for the surroundings of the Alhambra. Our study concerns the chemical analysis of the mural paintings on four facades, corresponding to numbers 23, 25, 27 and 29 of the Carrera del Darro. From the analysis of the mortar, it may be concluded that the composition is very similar, though not identical, in the four paintings studied: a limestone mortar. Ochre, white, black and red were used for the decoration of the four facades; green pigment was also observed in the second decoration of no. 29. The results of the morphological examination and EDX microanalysis of the paint samples are shown. By means of the thermogravimetric analysis we established the existence of an organically derived compound. After the existence of an oleaginous binder had been discounted by gas chromatography/mass spectrometry (GC/MS) analysis, we continued with the extraction and determination of proteins by spectrophotometry analysis, detecting low levels of proteins in the paint on the four facades analysed. The study was completed by evaluating the influence on the deterioration of the paintings by the possible surface presence of salts (such as nitrates or chlorides) and organic compounds.

Las pinturas murales de Castvlo. Primeras aportaciones a la caracterización de materiales y técnicas de ejecución

This article sets forth the research carried out on the wall paintings of the “Sala del Mosaico de los Amores” in the archaeological site of Castulo, located in Linares (province of Jaen). The research in 2011 discovered a room with high-quality wall and mosaic decoration, especially on its western wall, which had collapsed over the pavement. It was moved to the laboratories of the University of Granada for consolidation and restoration works. Since previous information on wall paintings from Castulo was scarce, before the restoration took place the paintings were studied, including the characterization of the materials and painting techniques. These tests identified a very rich pictorial layer, consisting of green, red, ochre, white and black tones, among which some high-quality pigments stand out, such as the Egyptian blue, together with others that usually appear in the Roman palette, as red lead, red ochres, bone-black or calcium carbonate.