The diagnostic investigation through minimal sampling for religious artworks knowledge: some case studies

Abstract

This contribution, starting from the fundamental assessment that artworks are unique and not-reproducible objects, reports the minimum investigation approach on some case studies, i.e. an approach based on a limited number of sampling points to obtain the maximum information as possible. This approach is particularly elevant and useful for investigating degradation patterns and material composition of artworks during a restoration process so that to correctly evaluate and choose the conservation strategies. Sampling techniques have been performed in relation to the artwork typology and to the information requested by conservators before or during the intervention. This information generally concerns the knowledge of the execution technique, of the state of preservation, of the materials, and of the possible dating, but is gathered with few analysis and samples in order to limit the invasiveness. The case studies selected for this paper are: the 16th century panel painting representing Saint George and the Dragon attributed to Raffaello; the 16th century canvas painting attributed to the Italian artist Cesare Nebbia depicting the pool of Bethesda, and one of the four 18th century medallions made of paper rags and representing life scenes of Saint Giacinta Marescotti from Viterbo. In all cases the minimum investigation approach demonstrated valid in supplying to the conservators the information requested, also with a single sample, and further data that could be gathered thanks to the availability of unexpected presence of micro-fragments in the sample/samples.