Raffaello or another painter?

21/1/2015

How modern non-destructive imaging techniques may increase the understanding and preservation of masterpieces

There are different advanced techniques in the field of non-invasive analysis in art conservation. New technologies for diagnostics and imaging applied to Cultural Heritage, based on lasers, optics and photonics, have been the focus of the International Workshop “THz-ART Project” held at the ENEA-Frascati Research Centre on December 3 – 4, in the framework of the Scientific and Technological Cooperation Programme between Italy and Japan, funded by the Ministry of Foreign Affairs and International Cooperation.

The workshop has been the occasion to present new promising applications of the Terahertz radiation diagnostic and imaging techniques developed by the ENEA as a result of a bilateral project involving Italian (ENEA-Frascati and CNR-IFAC) and Japanese (NICT-Tokyo & NNRICP-Nara) teams.

International researchers working in the field of non-invasive characterization of art materials have presented the wide spectrum of problems that non-invasive technologies can help to solve.

Of course there are advantages and limitations: Have you ever thought of bringing a precious Egyptian pottery piece to the hospital for a neutron imaging analysis? This is obviously unusual, but useful, if one have to compare three different methods of analysis, that are not all “portable”.

Moreover, if conservators have to investigate about the attribution of a famous painting, comparing three old master paintings hosted in important museums or private collections, you could use one of these non-destructive techniques, e.g. NIR (Near Infra-Red) reflectography or Terahertz imaging to provide additional information that can help in clarifying this issue.

Researchers at ENEA-Casaccia demonstrated how is it possible to study the underdrawing by NIR reflectography, thus revealing very important discoveries about the creative process and painting methods.

Michelangelo or another painter? This was the question. The comparison of the NIR images, linked to the information derived from documentation and art-historian literature, can provide evidences to ascertain the attribution of paintings and artworks to a determined artist. But also “pentimenti”, retouching, preparatory drawings, use of colour and many other aspects could be unveiled.

Similarly, there the Terahertz Advanced Research TEchniques of the THz-ARTE project will make it possible to “reveal” wonderful paintings covered by plaster layers.

Diagnostic and imaging techniques based on optics, infrared, microwaves, are indeed rapidly developing. With the “THz-ARTE project” various imaging techniques are extended to the GigaHertz and TeraHertz frequencies (the spectral interval between the infrared and the microwaves), since they provide useful data in the investigation of the internal-physical structure of paintings, mosaics, frescos and all non-metallic objects, without touching the artwork. Within the project ENEA is developing a portable instrumentation specifically designed to scan large areas of paintings in situ, thus overcoming the need to move the artwork from its site.

The first applications and prototypes of the Terahertz scanners and other imaging and diagnostic technologies were showcased in a hand on session, organized by the ENEA research team led by Gian Piero Gallerano (Head of the Radiation Sources Laboratory at ENEA-Frascati), together with the Institute of Applied Physics, CNR-IFAC Sesto Fiorentino, with the contribution of private enterprises. Attendees had the opportunity to have practical demonstrations of the different analytical tools.

The workshop, attended by researchers from all Europe and abroad, has seen a significant presence of the Italian world of art conservation and restoration. Among the attendes, important stakeholders as the Italian Opificio delle Pietre Dure in Florence, the Istituto Centrale per il Restauro e la Conservazione del Patrimonio Archivistico e Librario in Rome and the Vatican Museums.