The restoration procedure of the four pictorial ovals representing the Cardinal Virtues was similar to that used for the coat of arms. The mapping of the state of preservation showed a widespread degradation of the plaster (missing parts, detachments, cracks) and of the colors with alteration of the pictorial film due to various factors. In particular, the oval representing Justice was in poor condition due to significant water infiltration from the roof and particularly dark stains caused by the combustion of the paint during the fire of the ‘90s. For this reason, the work of cleaning and restoration was particularly thorough and complex. The painting of Prudence also presented the specific problem of a heavy orange tempera repainting, applied during a previous restoration to hide a large dark stain that was revealed during the intervention of SANSONE’s restorers.
The restorers performed cleaning trials on each painting to test the resistance of the pictorial surface before a more in-depth intervention. Afterwards, the cleaning was carried out both with dry techniques (dusting with soft brushes, removal of deposited materials with wishab gum) and with wet techniques (mainly with swabs and rinses of deionized water).
The painting of Fortitude, which had a very tenacious layer of dirt, underwent an initial superficial cleaning and then an intervention of consolidation of the plasters, before moving on to a specific cleaning based on compresses with sepiolite and fine cellulose paste, soaked in a saturated solution of ammonium carbonate, with Japanese paper interposed on the surface.
For Justice the cleaning was also carried out step by step, so as to identify with precision which were the traces of degradation from the repainting performed in the previous restoration after the fire.
For Prudence, it was necessary to remove the heavy repainting behind the central figure, using saturated water and specific products.
The interventions of consolidation of the plaster were similar for all four paintings and consisted mainly in injections of hydraulic mineral mortar, filling of the fractures with slaked lime and washed sand. In some cases the consolidation and cleaning works were alternated at different stages of work, respecting the specific problems of each painting. In particular, in the case of Justice, the consolidation of the pictorial film was carried out before the wet cleaning, since, due to it’s very compromised state of conservation, it would not have been able to adequately support the humidity brought in during this phase. This procedure allowed for the complete detachment of the black crusts before continuing with the spatula filling of the gaps in order to level out the unevenness of the surface.
Pictorial restoration and completion
Once the restoration of the plasters and the thorough cleaning of the surfaces were completed, we proceeded with the actual pictorial restoration, aimed at reconstructing the painted figures as completely as possible, maintaining the original style. The pictorial retouching was carried out in order to adapt it as much as possible to the original drawing, integrating the plastered gaps and abrasions with color glazes that respected the original colors. Tempera mixed with mineral pigments (soils and oxides) or pigments diluted in acrylic resins and watercolors were used. Even in this last phase, the choice of techniques and materials was made according to the characteristics of the individual works, in order to intervene in a focused manner.