A Characterisation Study on Modern Bronze Sculpture: The Artistic Patinas of Nado Canuti

ABSTRACT

Artistic patination is a traditional colouring technique for metal sculpture, employed by artists in ancient and modern times for aesthetic purposes. Today, knowledge of the artistic value and the chemistry of this superficial chromatic layer, called ‘artistic patina’, can be successfully acquired through a close collaboration between living artists, foundry artisans, and scientists. Starting from several interviews with the Italian artist Nado Canuti and foundry artisans, specific information was gathered about patination methods and the artist’s attitude towards materials restoration. Afterwards, the patinas most used by Canuti were reproduced to study their nature before any ageing or degradation. Their chromatic values, morphologies, and compositions were studied employing a range of techniques such as colour measurements, scanning electron microscopy with energy dispersive X-ray spectroscopy, and micro-Raman spectroscopy. The collected data revealed the formation of main compounds (cuprite, cassiterite, rouaite, chalcocite, isocubanite, and ferroxyhite) and additional compounds (atacamite and CN-containing compound). The scientific results, as well as the artist’s statements concerning the patinas’ significance, maintenance, and conservation, will contribute towards the future care and preservation of Canuti’s sculptures.

KEYWORDS:

• Artistic patina
• modern bronze sculpture
• artist interview
• Nado Canuti
• SEM-EDX
• micro-Raman spectroscopy

Acknowledgements

The authors would like to thank the artist Nado Canuti for providing invaluable information on the creative process that leads him to create works of art, and the Fonderia Artistica Mapelli for giving us the access to the foundry and the materials used to produce artistic patinas.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Mila Crippa is a conservation scientist in the field of Cultural Heritage. She holds a Master Degree in Technologies for Conservation and Restoration of Cultural Heritage at the University of Genoa. Her experience includes scientific analyses on modern paintings and sculptures using non-invasive and invasive technologies.

Valeria Bongiorno is Research Fellow at the Department of Chemistry and Industrial Chemistry of the University of Genoa. Her research activity concerns the study of contemporary metal artworks, the LASER cleaning technique on copper based alloys, metal additive manufacturing and stainless steels for high temperatures.

Paolo Piccardo is Professor (AP) of Metallurgy at the Department of Chemistry and Industrial Chemistry of the University of Genoa. His research interests include renewable and alternative energy sources, failure analyses, copper and iron base alloys in object belonging to Cultural Heritage (e.g. understand and rebuild the manufacturing process and the interaction with the abandon environment).

Maria Maddalena Carnasciali is Research Professor at the Dept. of Chemistry and Industrial Chemistry of the University of Genoa. Her main research activities focus on intermetallic compounds with Rare Earths, high critical temperature superconductors, low molecular weight organic compounds and application of Raman spectroscopy in cultural heritage research.

ORCID

Maria Maddalena Carnasciali http://orcid.org/0000-0001-9680-7404