Investigación científica de las obras de arte: estudio comparativo de los pigmentos y de la técnica pictórica de los retablos de Santa Elena y San Blas

Comparative analysis of the pigments and paintings techniques of two 16th-century altarpices, the altarpieces of Santa Elena and of San Blas, have been carried out by x-ray diffraction, optical microscopy, scanning electron microscopy and x-ray photoelectron spectroscopy. The results show that the fundamental difference in the pigments used corresponds to the block colour wich is carbon black in one and a copper compound in other one. More differences are noticed in the painting techniques. After analysis, restoration was carried out on the altarpiece of Santa Elena, which presented numerous damage due to insects, dirt, cracks and losses in the paint layer. The restoration included: disinfection with pentachlorophenol, consolidation of the support with epoxy resin, consolidation of the paint layer with colleta and hot spatula, cleaning with solvent (base N- butylamine) and mechanically, reintegration with the rigatino method, final coating with thermoplastic polymers.