On the application of Optical Coherence Tomography as a complimentary tool in an analysis of the 13th century Byzantine Bessarion Reliquary

Accepted version (after embargo period)This work presents the results of an application of optical coherence tomography (OCT) to examine a 13th century Byzantine reliquary of unparalleled artistic and historical value. The aim of this work, performed at the initial stage, before the restoration, was focused on the resolution of cleaning procedures regarding both the thick, old varnish and the gold leaf details finely applied on the painted parts of the artwork by means of an integrated approach of non-invasive and invasive analyses and diagnostics. The results allow definition of the thickness of the varnishes, their inner morphology and establishes the presence (or absence) of secondary layers of gold leaf upon the original ones. Knowledge of varnish thickness and in-depth localisation of the secondary gold leaf allowed the restoration procedure of cleaning and thinning of the altered varnish to be performed safely and effectively in order to recover the wonderful pristine sight of a precious and ancient byzantine work of art

La salvaguardia dell'ambiente e del biota nel settore dei beni culturali

In the past the unsuitable choices made when choosing products to be used for conservation actions related to artefacts of historic-artistic interest were mainly due to wrong assessments. More specifically this means: insufficient determination of the structure-aspect relation which characterises the original materials that make up the artefacts; insufficient knowledge of the behaviour of new materials due to natural ageing processes which might impoverish them or deprive them of specific qualities; lack of interest in measuring the medium-long term effects and interactions of the artefacts-products-environment system. The latter is sometimes capable of triggering new and more serious factors leading to the deterioration of the artefact sometimes causing even greater damage. In particular this study refers to the aspects related to the potential danger deriving from products used for the different types of conservation interventions on stone materials

Nuovi metodi e tecniche per il restauro delle opere d'arte nell'Opificio delle Pietre Dure

The text presents a methodological approach to restoration from the point of view of a Ministry with a well-established tradition, mainly from the diagnostic and operational viewpoint. The topics dealt with include post-restoration monitoring and new methods for laser cleaning, also for paintings. Finally a suggestion is made for a revision of the largest restoration works of the past thirty years in order to assess, on the basis of the experience acquired, the progress and knowledge achieved, the various methods, approaches, successes and failures

Micro-Stratigraphical Investigation on Corrosion Layers in Ancient Bronze Artefacts of Urartian Period by Scanning Electron Microscopy, Energy-Dispersive Spectrometry, and Optical Microscopy

The results of the analysis on some fragments of bronze belts and a bowl discovered from southwestern Armenia at the Yegheghnadzor archaeological site are discussed. The samples are dated to the 7–6th millennium BCE from the Urartian period. The artefacts were corroded, and a multilayer structure was formed. To study the stratigraphy of layers and their composition, the samples have been analyzed using SEM-EDS (Scanning Electron Microscopy, Energy-Dispersive Spectrometry) and OM (Optical Microscopy) techniques. The bronze finds appear with the typical incrustations rich in alloy alteration compounds. Concentrations of copper and tin in the alloys were quantified by SEM-EDS: the pattern and the percentage of the alloy are the same for the belts. Regarding the bowl sample, it is constituted by two foils perfectly in contact but different in color, thickness, and composition. The results evidenced that only two elements participate in forming the alloy composition in the samples: Cu and Sn. The tin content is variable from 7.75% to 13.56%. Other elements such as Ag, As, Fe, Ni, P, Pb, Sb, and Zn make up less than 1% and can be considered as impurities

Non-invasive FTIR characterisation of varnishes of ancient brass scientific instruments belonging to the “Physic Cabinet” of the “Fondazione Scienza e Tecnica” in Florence

A series of over 40 scientific instruments belonging to the collection of “Fondazione Scienza e Tecnica” in Florence were submitted to scientific investigation by means of a portable Fourier transform infrared spectroscopy (FTIR) instrument (Bruker Alpha) in order to characterise the varnishes applied on the brass parts and surfaces. Brass is one of the most used materials for scientific instruments, with wood and glass, and the issue of its protection was taken into account since the earliest manufacturers. The literature reports various recipes of so-called “lacquers”, most of them based on alcohol and mixtures of several natural resins, gums and dyes. In a previous work [1] the authors did search these recipes and replicate a series of brass historical lacquers; they were applied in thin film on a polished brass plate, then aged and examined by means of reflection FTIR. The quality of the spectra collected was very high because the phenomena of “transflection” in which the flat metal surface reflects the whole incident radiation doubling the beam path and straightening the peaks. In this work the authors have chosen a large selection of scientific instruments used for research and didactics in physics and manufactured in Europe in the nineteenth century, with the aim to characterise the brass varnishes, to detect the ingredients formulation and to organize a comparison among the various instruments, according to the geographical provenience, the time and the workshop of production. The use of a portable FTIR equipment, working in total reflection mode, enabled us to analyse in a non-invasive way a large number of brass containing scientific instruments and, in some cases, the possibility to disassemble some parts or details offered a great help to the investigation of the surface. The results are organised in “families of lacquers” according to the spectra similitudes, and each family related to the geographical area of provenance. The importance of this work is also in the well-known geographical production of the scientific instruments belonging to the FST collection: this could be of great importance as a reference base of the instrument provenance, in case of unknown manufacture. The final aim of this work is to start the building up of a freely available database of brass scientific instruments varnishes, useful for conservation scientists and collection curators, in order to catalogue and compare the lacquers composition. It represents also a guide for restorers and conservators to make informed decisions on the processes to adopt to preserve and restore the original varnishes. [1] Anna Giatti, Giancarlo Lanterna, The non-invasive FTIR characterisation of brass varnishes of historical scientific instruments. Proceedings of the conference Technart 2015, Catania 27-30 april 2015, O - 8

Historical, analytic-diagnostic and environmental study of the wood ceilings covered in painted paper in “Casa Romei” (Ferrara): Room of the 1500s

This study aims at the evaluation of the conservation state of painted paper ceilings in the museum of Casa Romei (Ferrara). These ceilings are very important as rare witnesses of the art in Ferrara in 1400 to simulate wooden ceilings through painted paper. The overall project, proposed for the study of both the manufacture techniques and the state of conservation, is divided into two stages relative to the knowledge of the materials and the conservation environment. The study involves the artefacts control (diagnostic, materials and products characterisation through biological and chemical analyses) and microclimate monitoring