Learning from the past, intervening in the present: the role of conservation science in the challenging restoration of the wall painting Marriage at Cana by Luca Longhi (Ravenna, Italy)

Abstract

The paper discusses the case study of the Marriage at Cana, a sixteenth century wall painting located in Ravenna and executed by Luca Longhi. A multi-analytical approach based upon OM, SEM-EDS, μ-Raman, μ-FTIR and biological analyses was selected to investigate the painting technique and the state of preservation of the artwork, compromised by a severe alteration. Data demonstrated that the artwork was executed with a dry painting technique: a siccative oil was used as binder, while indigo, lead white, carbon black, ochres, vermilion and red lead were identified as pigments. Biological analyses clearly allowed identifying Eurotium halophilicum as the fungus responsible for the white patina compromising the painted surface and, according to this result, Biotin T was selected as the most effective biocide to stop the biological attack. The precarious conditions in which the painting was, attributable to previously performed interventions and to the conservation environment, laid the groundwork for a challenging restoration conducted in 2016. Scientific analyses better clarified the kind of materials employed in the execution on the artwork, as well as how the previous restoration was carried out; furthermore, analytical data methodologically supported phases of the intervention like cleaning, filling of the lacunae and pictorial retouching, as products were selected on the basis of their affinity to original materials and painting technique. This study will hopefully encourage reflections on how a synergic dialogue between conservation science and restoration can represent an important reference point for interventions to be conducted with scientific criteria and suitable methodology, in the light of the shared vision and common goal of transferring patrimony to future generations.

The Control of Cultural Heritage Microbial Deterioration

“…Despite their toxicity, traditional biocides are still largely employed to contrast biodeterioration [ 15 , 16 ]. However, biocidal treatments have a brief duration and must often be repeated frequently, creating a repeated threat to the heritage material and the environment [ 17 ].…”

Revealing time’s secrets at the National Theatre of Costa Rica via innovative software for cultural heritage research

“…In this study we used Multispectral Imaging (MSI), an affordable, non-invasive and non-destructive technique which relies on a photography system to map and identify pigments, binders, and retouched areas of the paintings 9 . MSI allowed us to verify the painting technique and evaluate the current state of the paintings, including damage and possible restorations 1 , 10 . In order to quantitatively examine the colours, most studies have recreated reflectography spectra for a selected painting region using MSI; however, the main drawback of this technique is that it requires many filters and it is very time-consuming 9 , 10 .…”

“…More specifically, we believe these tools represent an important step forward in restoration efforts and preventive methods, since they allow for guided microbiological sampling, even before fungi have caused visible damage. Using these computational tools in a pilot study, regions of interest were isolated from the rest of the artwork in order to study stratigraphies of individual samples and carry out microbiological sampling, alongside environmental monitoring of the painting’s surroundings, as these are key factors for efficient modern public policies in cultural heritage 1 .

Figure 1 In the flow of time.

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“…For instance, a study in Linares, Spain combined the use of Energy Dispersive X-ray Fluorescence ( EDXRF), surface mapping and single-spot micro-Raman spectroscopy to identify the chemical composition of pigment layers in wall paintings at the Cóstulo site 14 . Another MAS was carried out on the large-format painting Marriage at Cana by Italian artist Luca Longh, located in Ravenna, Italy, to identify its technique and state of conservation 1 . This study revealed the materials used in the work, and that it was executed using the dry painting technique.…”

“…Art pieces imported into Latin America are more likely to be affected by the effects of temperatures and humidity of the tropics. There are many studies on the conservation and restoration of large-format artworks, involving the techniques discussed above, but they took place in Europe 1 , 19 – 22 and did not address tropical factors. There are even fewer restoration protocols suited to the works in question.…”