Protective treatments to be applied in the field of cultural heritage need to fulfil several constraints that have gradually been better outlined over the years. Along with the impact on aesthetic appearance and reversibility, it is nowadays well recognized that patinas and/or original historical coatings and finishings can play a relevant role in protective treatments’behavior[1,2]. Nonetheless, no standard characterization method has been drafted to test new coatings and their application on real artefacts