Non-invasive optical techniques for degradation assessment: A case study of expanded polystyrene in the artwork 'Cartoline' by Stefan Arienti"

This study illustrates the results of scientific investigations based on a non-invasive optical technique (Fiber Optics Reflctance Spectroscopy, FORS) applied to the artwork "Cartoline" ("Postcards"), by the artist Stefano Arienti. The artefact, dated 1990, is entirely constituted by large expanded polystyrene (EPS) panels and belongs to the permanent collection of the Contemporary Art Center "Luigi Pecci" in Prato (Italy). This artwork has been recently submitted to a general survey aimed at establishing its conservation state and the possible strategies for its maintenance and preservation. The presence of both photo-induced and mechanical degradation signs indicated the need of urgent interventions to safeguard the artwork and prevent further degradation. In-situ measurements performed by means of FORS allowed a non-invasive characterization in the UV-Vis-NIR spectral range of the EPS panels. The spectroscopic analysis was aimed at building a map of the degraded areas on the panels surfaces, in order to ascertain if they could be attributed to the actions of the fluorescent tubes usually employed to back-illuminate the artwork. The scientific study was integrated with an interview to the artist Stefano Arienti, in order to take into account the artist point of view in the conservation strategy.