In the last decades, the interest in the development of protective coatings for movable and immovable Cultural Heritage (CH) assets has decidedly increased. This has been mainly prompted by the raising consciousness on preservation requirements for cultural artefacts and monuments, which has consequently determined the development of new protective products. From acrylic resins used at the end of the last century to the up-to-date biomaterials and nanoparticles employed nowadays, the research has made a giant step forward. This article reviews the progresses, the technical challenges, and the most recent advances in protective coatings for archaeological metal, glass, and stone artefacts. It aims at offering a comprehensive and critical overview of the progressions in conservation science and displaying how research has optimized polymers in order to solve deterioration problems. Attention is given to recently developed materials, hybrid coatings, and corrosion inhibitors. This work seeks to provide a reference point for future research and to offer a wide-ranging introduction on the newly available material technologies to restorers and conservators.

A set of ancient Antoninianus silver coins, dating back between 249 and 274 A.D. and minted in Rome, Galliae, Orient and Ticinum, have been characterized. We use, for the first time, a combination of nano-invasive (focused ion beam-field emission scanning electron microscopy-X-ray microanalysis (FIB-FESEM-EDX), voltammetry of microparticles (VIMP)) and destructive techniques (scanning electron microscopy (SEM-EDX) and electron microprobe analysis (EMPA)) along with non-invasive, i.e., micro-Raman spectroscopy. The results revealed that, contrary to the extended belief, a complex Ag-Cu-Pb-Sn alloy was used. The use of alloys was common in the flourishing years of the Roman Empire. In the prosperous periods, Romans produced Ag-Cu alloys with relatively high silver content for the manufacture of both the external layers and inner nucleus of coins. This study also revealed that, although surface silvering processes were applied in different periods of crisis under the reign of Antoninii, even during crisis, Romans produced Antoninianus of high quality. Moreover, a first attempt to improve the silvering procedure using Hg-Ag amalgam has been identified.

We are moving towards a future that must be more sustainable in several aspects of society. Culture and cultural heritage have been recognized as indispensable parts of the sustainable growth of society, and the conservation model implemented in Europe has been considered as an example to follow at the economic, environmental, and social levels. The achievement of excellent results and the development of new technologies for the conservation of cultural heritage have highlighted the fundamental need for a method of sustainable conservation. In this commentary paper, we discuss two aspects that can contribute to sustainability in the future of conservation science: the use of innovative chemical products and the monitoring of outdoor sites by means of the forecast of the impact of dangerous factors on artistic surfaces. We are focusing mainly on the material aspect of cultural assets and how hard science can help in sustainable conservation. Even if the concept of sustainability has an ever-growing presence in our society, and different approaches have been given in different fields, it is still difficult to come up with a specific definition that can include the various hues of the world of cultural heritage conservation. The case studies presented in this paper are related to the European area and the advancements made for the sustainable preservation of such heritage. Considering the results obtained from both the chemical and the forecast side, we will try to summarize concisely the tasks that must be achieved in order to indicate as sustainable an approach to diagnostics for cultural heritage, including both the trans-disciplinary features of cultural heritage science and the scientific conservation of materials.