Figure 4From: Setup of a sustainable indoor cleaning methodology for the sculpted stone surfaces of the Duomo of MilanColorimetric characterization of the stone surface before cleaning. Results are separately reported according to the a* and b* colorimetric coordinates (A), and to the surface lightness (B). Vertical areas with rough finishing (-VR) are indicated in green; inclined areas with rough finishing in red (-IR); vertical areas with semi-polished finishing in yellow (-VS).Back to article page