Decorated corams of palazzo Chigi: characterisation and preservation treatment

With the aim of the care and preservation of collagen-based objects, a study was conducted on the leather wallpapers adorning the Palazzo Chigi rooms. Several rooms of the building are enriched with decorated corams of the seventeenth century while numerous fragmented and incomplete wallpapers are, instead, preserved in the archives of the palace. As all the collagen-based artefacts, these aged leather fragments can be easily damaged by natural causes or by incorrect treatments/preservation conditions. Altered conditions of humidity and temperature can generate serious effects on the artefacts, accelerating their deterioration and increasing the possibility to incur in bio-deterioration agents causing permanent damage to the leather. Improper handling or exposure to light can also fade dyes and pigments, inducing cumulative irreversible damage up to the loss of the decoration itself. Generally, the methods used to treat bio-deteriorated historical leather objects are always under review and many of the former results might be obsolete. Thanks to the availability of Palazzo Chigi's heritage and samples, the application of ionizing radiation produced by ENEA's REX machine, as a method for reducing the bio-deterioration of these leather objects while preserving their characteristics and their historical and artistic value, has been investigated. In the course of this study, it has also been possible to perform different characterizations of these interesting artefacts with the aim of analysing their chromatic richness, the employed materials and the iconographic elements in order to improve the knowledge of peculiar decorations of the Palazzo Chigi rooms.