Tof-SIMS spectra of historical inorganic pigments: Calcium white pigments in both polarities

Abstract

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is increasingly used to analyze cultural heritage materials because it can simultaneously detect organic and inorganic materials while mapping them on a surface. The precise identification of a pigment in a specific layer of a painting or of remaining color on a statue can inform about the technique used or the time of manufacture as well as expose possible forgeries when anachronistic ingredients are identified. Reference spectra are required to confidently identify a given pigment using ToF-SIMS. This database focuses on six white pigments made from calcium-rich natural or synthetized materials, prepared following traditional processes. Such pigments are frequently found in the preparation layers, namely, “ground,” separating the support from the observable paint layers, and providing a smooth surface to hold the paint on while preventing its absorption by the substrate. Differentiating between these pigments is helpful to better describe the painting practice. Here, ToF-SIMS reference spectra using a Bi3+ primary ion species are presented for both polarities.