Colorimetric and spectral data analysis of consolidants used for preservation of medieval plasterwork

Abstract

The incorporation of new methods of heritage analysis belonging to other branches of science is currently providing very useful tools for the examination of preservation products. This paper outlines the use of spectral images as an alternative to traditional colorimetry measurements carried out with a spectrophotometer for the evaluation of color changes produced by consolidation treatments applied on polychromed plasterwork. Thus, for this investigation we used a total of 18 plaster test specimens which reproduce the techniques and materials present in plasterwork from the medieval era, on which a selection of six currently-used consolidants was applied. By doing this, we have proved that the use of this method over traditional colorimetry has several advantages, such as the analysis of spatial homogeneity or obtaining colorimetric data of the entire scanned surface.