Compositional depth profiles of gilded wood polychromes by means of LIBS

Abstract

[Resumen] Se analizan las diferentes capas existentes en retablos de maderas policromadas del periodo barroco. Se distinguen la capa base y las posteriores hasta el acabado mas superficial. Se aprecian las diferentes técnicas aplicadas en función de la procedencia y del autor que las ha realizado.

[Abstract] Gilded wood polychromes are important artistic expressions in Galicia (NW Spain) during the baroque period. The variety of techniques applied in gilded ornamentation and the possible existence of products of previous interventions make difficult the restoration process of these artworks which frequently include the removal of a brass-based paint (purpurin) added to cover the lack of gold leaf. The aim of this work is the characterization by means of LIBS of the different layers in gilded wood polychromes. For this purpose small pieces taken from two baroque altarpieces were analyzed using a Nd:YAG laser source operating at the wavelength of 355 nm to obtain characteristic LIBS spectra and compositional depth profiles.