ABSTRACT
ABSTRACT: This study is based on the evaluation of ultraviolet exposure of painting woods. Two model painting samples have been developed according to Cennino Cennini with 11 pigments that were mixed with proteinaceous binding based on eggs and rabbit glue. The pigments, binders and mixtures were characterized before and after laser tests by an X-Ray diffractometer, a FT-IR Spectroscope with Attenuated Total Reflectance (UATR) accessory, an Optical Microscope, an EDS-SEM Microscope and a colorimeter. The laboratory experiments were carried out at a climatic chamber at 20ºC and 40% relative humidity. A lamp of 350 nm was employed and the samples were analyzed after 200 and 400 hours of exposure. The pigments with the highest color changes are carmine and ultramarine, followed by vermillion and indigo. The green earth is the pigment that suffers the smallest color change. Colour variation (ΔE*) is generally higher with egg binder than with animal glue.
