The analysis of European lacquer : optimization of thermochemolysis temperature of natural resins

In order to optimize chromatographic analysis of European lacquer, thermochemolysis temperature was evaluated for the analysis of natural resins. Five main ingredients of lacquer were studied: sandarac, mastic, colophony, Manila copal and Congo copal. For each, five temperature programs were tested: four fixed temperatures (350, 480, 550, 650 degrees C) and one ultrafast thermal desorption (UFD), in which the temperature rises from 350 to 660 degrees C in 1 min. In total, the integrated signals of 27 molecules, partially characterizing the five resins, were monitored to compare the different methods. A compromise between detection of compounds released at low temperatures and compounds formed at high temperatures was searched. 650 degrees C is too high for both groups, 350 degrees C is best for the first, and 550 degrees C for the second. Fixed temperatures of 480 degrees C or UFD proved to be a consensus in order to detect most marker molecules. UFD was slightly better for the molecules released at low temperatures, while 480 degrees C showed best compounds formed at high temperatures

Investigating the colourful world of Alessandro Mendini: Perserving Nigritella Nigra, a unique chest of drawers decorated with grease crayon drawings

This paper discusses the decision-making process and the conservation treatment of Nigritella Nigra (1993), a chest of drawers designed by Alessandro Mendini (Milan, 1931-2019. (1)). The top drawer case is decorated with several colourful abstract crayon drawings, making the chest a unique work of art. The varnish on top of these drawings was peeling off, lifting the crayon with it, with loss of material as a result. This study analyses the factors that may have contributed to the degradation process and describes the research performed preceding treatment, including ethical, aesthetical and artistic perspectives. Information from an artist interview has enriched deliberations in decision-making. For material analysis Py-GC/MS and FTIR were used, identifying grease crayon as medium for the drawings and cellulose nitrate (CN) for the varnish. Various options for consolidation and retouching were considered and tested, and a suitable approach was found with satisfactory result