Chromatic behavior of inorganic pigments in restoration mortars (nonhydRaúlic lime, hydRaúlic lime, gypsum, and Portland cement). A comparative study

Abstract

Spectral diffuse reflectance was used to make a comparative study of the chromatic behavior (stability, coloring power and effects of time, thermal gradients, and high energy ultraviolet radiation) of the inorganic pigments ultramarine blue, green earth, molybdenum orange, zinc yellow, chrome yellow, chrome green, ochre, and natural sienna when mixed with the binders: nonhydRaúlic lime, hydRaúlic lime, Portland cement, and gypsum. The results show acute interference of the limes and the Portland cement, and, to a lesser extent, of the gypsum on the initial colors of ultramarine blue, molybdenum orange, and chrome yellow. The other pigments studied showed good stability in the four binders. Time, thermal gradients, and high energy ultraviolet radiation caused no appreciable color changes, except in the case of chrome yellow, which presented slight changes over time. © 2006 Wiley Periodicals, Inc.