Diagnostic investigations

Like any complex intervention, the Bardi project began with a careful phase of documentation of the state of the painted surfaces, first of all through a high-resolution photographic campaign in diffused light, grazing (LR image) and ultraviolet. The latter in particular provides useful results for identifying the presence and distribution of different materials, both belonging to the execution phase and to any previous restorations. Thanks to the collaboration with the University of Genoa, on the basis of a laser scanner survey, a HBIM 3D model of the entire chapel was obtained on which all subsequent analyses were integrated.

A campaign of structural examinations was then carried out, first of all, a georadar survey of the Chapel using an innovative no-touch device, which made it possible to collect valuable information for the knowledge of the wall structure and the identification of any inhomogeneity.  Then, with the help of a thermal camera, the analysis was refined to identify the scaffolding holes and any detachment between the plaster.

In this fundamental phase of preliminary knowledge, some European research laboratories that develop non-invasive and mobile tools have also intervened and various analysis tools were involved with the aim of recognizing and mapping the sub-surface detachments of the plaster, as well as to try to recognize the areas of detachment subject to past fillings 

Although heavily compromised, Giotto's painting has regained an extraordinary freshness in some passages, for example in the faces so carefully characterized and which have been better preserved because they are all frescoed, which is a particularly resistant technique.

The chapel shows a dense presence of small gaps, dating back almost entirely to the nineteenth century, at the time of the rediscovery of the Giotto cycle, due to the insertion of nails or the damage produced at that time. These had already been grouted during previous restorations: today, the choice was made to remove those replaced in the last century with vinyl-based mixtures, using instead a mixture of lime and sand more compatible with the original material. All this was an important premise for the observations and for further scientific examinations.

Following the results of the cleaning operations that are almost completed, with the support of the Scientific Committee, the reflection must be carefully set on the final image that Giotto's decoration may assume in the light of modern considerations on the nature of the large and small gaps that so massively mark the pictorial text to allow a better readability.