Multispectral analysis of ancient Maya pigments: implications for the Naj Tunich corpus

Naj Tunich, in southeastern Peten, Guatemala, is one of only five caves currently known to contain Maya hieroglyphic writing. It is universally recognized as the preeminent Maya cave site because its corpus ofinscriptions exceeds those of the other four caves combined. In June of 1998, over half of these inscriptions were documented at visible and near-infrared wavelengths using multi-spectral imaging techniques. Spectral differences were noted in the Naj Tunich images especially in the infrared. Spectral signatures were used to identify differences in the Naj Tunich pigments and suggest that at least three different pigments were used. More importantly, the ability to document spectral differences reveals far more complexity in the Naj Tunich corpus than previously appreciated. Several instances of over-painting, repainting or touching up were discovered. The cases of over-painting reveal the temporal complexity of the drawings and suggest that the painting occurred over a longer period of time than had been proposed by previous investigation. The ability to characterize pigment composition using spectral data has also led the authors to question a number of relational differences and similarities between drawings proposed on the basis of stylistic analysis