Rare Objects as Painting Substrates: The Example of a Seventeenth-Century Portable Icon

Abstract

Representing St. Athanasios of Alexandria, and found buried a century ago in Northern Greece, the portable icon under study displays a rare substrate; its panel is a unique example of a wooden instrument in secondhand use. In particular, a threshing board, a common in the Mediterranean basin agricultural instrument, was used as the panel of the icon. Optical and UV microscopy, X-ray radiography, SEM-EDS microscopy, and μ-FTIR spectroscopy were employed to determine the state of preservation and to identify the applied materials and pigments. The stratigraphy of the painting includes the wooden substrate, a textile support of cotton fibers, and the ground layers which consist of anhydrite, gypsum, and rabbit skin glue. The gilding consists of a gold and silver alloy foil, applied with the use of bole. A simple palette of red, brown, white, and black colors was used for the painting layers. Ochre, minium, calcite, lead white, and bone black are the identified pigments. The identification of egg yolk implies the use of egg tempera technique. The remaining traces of varnish were identified as of plant origin, most probably mastic. All of the icon’s characteristics – the materials and pigments and the stratigraphy (e.g., mastic varnish, cotton textile support, bole, repousse halo, and egg tempera technique) – are typical of the seventeenth century.