Materials Characterization with Multiband Reflectance Imaging at the Brooklyn Museum: A New Tool for the Multiband Imaging Kit

In pursuit of accessible tools for non-invasive examination, Brooklyn Museum (BkM) conservators experimented with using multiband reflectance imaging (MBR) to characterize materials in the collection. This imaging technique visualizes materials that have a pronounced difference in reflectance across defined spectral bands, essentially providing a map of an object’s surface. MBR involves using bandpass filters to capture one image in the visible-light range and one image in the near-infrared range and combining them in post-processing. As few references to MBR exist in the literature, BkM conservators not only evaluated the information gained from its application, but also investigated the technique itself.Since 2016, BkM conservators have used MBR in concert with other scientific analyses to localize the presence of indigo, Maya blue, lapis lazuli, and ultramarine blue on works in the collection. This paper presents an overview of the MBR protocols developed at BkM and their application, in addition to discussing challenges associated with equipment setup, image processing, and interpretation. The authors also address current investigations into the different effects of grayscale conversion functions and a new approach to MBR processing.