Connecting Stories: Investigations of a Seventeenth-century Mercator Hand-painted Map

Abstract

ABSTRACT A seventeenth-century hand-painted map entitled Walachia, Servia, Bulgaria, Romania, printed with the original copper plate engraved by Gerardus Mercator, was investigated using portable, non-invasive spectroscopic and imaging methods. X-ray fluorescence spectrometry, UV fluorescence imaging, and short-wave infrared hyperspectral imaging were correlated to characterize pigments, differences in materials, previous interventions, and specific types of degradation. The results showed evidence for the use of vermilion, red lead, a green copper-based pigment, a gray-blue cobalt-based pigment, a chromate-based yellow pigment, and gold leaf, and even inferred the possible use of black ferro-gallic ink, thus highlighting both original materials and the likely presence of at least one previous restoration from the nineteenth century. Hyperspectral imaging was able to discriminate the most significant coloring materials, while UV fluorescence imaging suggested the use of organic material, both as a coating for the gold leaf and as a component in the mixture to temper the vermilion and the green copper-based pigments.