Baroque stucco decorations and 20th century restorations. Materials, techniques and conservation issues

In the XVII and XVIII centuries stucco decoration played a key role in church architecture. An example is the parish church in Castel S. Pietro in Swiss. Many stucco artists were born in this area and worked in many royal courts of Italy and Europe. Many famous artists like Silva, Barberini and Pozzi worked with secret techniques in this church. In recent decades problems of decay (leaking roofs, capillary rise in damp walls, salt efflorescences, thermal expansion, oxidation of metal elements in the stucco objects and differential movement in different layers) urgently need to be solved. Defining a conservation and restoration project for the decorative ornamentation involves decisions and considerations based on a detailed appraisal, organized and multidisciplinary in nature, capable of merging bibliographical and archival data with the “material fabric” from which the artifacts are made, as well as the events that have impacted on the works, such as restorations and accidental damage. The intrinsic complexity of stucco artworks necessarily called for an in-depth understanding. Key challenges were to give answers to many questions about methodology and techniques