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Raman spectroscopy and time of flight secondary ion mass spectrometry (ToF-SIMS) were used to answer conservation questions left open after the preliminary analysis performed by the restoration team on the Bosch painting Saint Wilgefortis Triptych, within the project "Bosch in Venice." In this work,we present the results obtained by combining these two techniques on five cross sections, concerning a detailed study of pigments and bindings degradation processes, the identification of organic components (binders/lakes), and the characterization of restoration products. Raman measurements show the presence of degradation products, such as calomel on the red pigment cinnabar, calcium-oxalate, in particular weddellite, localized in a not original external layer, and finally lead soaps in several layers of the investigated samples.Although the detection of lead soaps suggests the use of oils as binders, Raman spectroscopy has given no conclusive information about such binders, neither on the possible presence of red lakes, suggested by independent UV observations. Complementary ToF-SIMS investigations have instead revealed the presence of lead palmitate and stearate in the painting layers along with miristic, palmitic, oleic, and stearic acids, thus confirming the use of an oil medium, likely linseed oil. Additionally, ToF-SIMS shows the presence of polydimethylsiloxane, likely from a previous restoration treatment in the 1990s, in the external layer of the investigated cross sections. Due to experimental difficulties during the analysis of the red lake, we can only hypothesize the presence of alizarin.

The study of micro-objects, both inorganic and organic, which can be found associated to parchment or cellulose fibres of books and documents, or in the inks and the dirt, accumulated over the centuries between the pages, can unravel important information on the manufacture of the ancient documents, on their past vicissitudes or on the causes of aging and deterioration of the materials they contain. The results of a critical observation of micrometric objects and structures with a diagnostic or archaeological significance have in some cases been surprising. Apart from the curiosity that certain findings may or may not raise, what needs to be discussed is the fact that some chemical components, usually attributed to the manufacture of materials or the inks may instead have a particular origin and nature, and therefore lead, if not properly highlighted, to some erroneous diagnostics. Examples are given where the information obtained by means of scanning electron microscope imaging and Raman microscopy were coupled with dispersive X-ray microanalysis and Fourier Transform Infrared Spectroscopy.

Time of flight secondary ion mass spectrometry (ToF-SIMS) has become a fundamental analytical technique in cultural heritage studies to obtain the identification and distribution of organic components present in artworks. A sample taken from the soldier's golden shield decoration in the fresco Vela della Castità (San Francesco Lower Basilica, Assisi) was studied. The metal leaves for gilding decoration on wall paintings are usually applied using an oil-resin mordant as adhesive. In this work, organic and inorganic compounds used in this peculiar painting technique were identified by ToF-SIMS technique. High mass resolution spectrometry was applied for the chemical characterization of organic materials present in oil-resin binding media and red lake paint layer. Presence of azelaic, palmitic and stearic acids proved the nature of the oil binder between plaster and tin leaf and between tin and gold leaf. The analyses revealed also the presence of colophony, a natural resin used as an adhesive in this painting technique. Furthermore, the fresco cross section was studied using ToF-SIMS imaging. ToF-SIMS results agree with and are complementary to those obtained by other analytical techniques: scanning electron microscopy with X-ray microanalysis and Fourier transform infrared spectroscopy.

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