Evolved Gas Analysis-Mass Spectrometry to Identify the Earliest Organic Binder in Aegean Style Wall Paintings.

An organic binder was identified in the painted fragments from the Canaanite palace of Tel Kabri, Israel. Recently dated to the late 18th century B.C.E. by 14 C, Tel Kabri is the most ancient of the Eastern Mediterranean sites in which Aegean style paintings have been found. The application of pigments was suspected to be using an organic binding medium, particularly for the Egyptian Blue pigment. Samples of blue paint were examined using evolved gas analysis-mass spectrometry (EGA-MS) in order to overcome the analytical challenges imposed by highly degraded aged proteinaceous materials. Egg was identified as the binder based on the presence of hexadecanonitrile and octadecanonitrile, confirming the use of a secco painting technique. Lysozyme C from Gallus gallus was detected by proteomics analysis, confirming the presence of egg. To our knowledge, this is the earliest use of egg as a binder in Aegean style wall paintings.

Visible induced luminescence reveals invisible rays shining from Christ in the early Christian wall painting of the Transfiguration in Shivta.

The Transfiguration scene depicted in a Byzantine church at Shivta, Israel, is one of two figurative examples of the scene from the early Christian period. The use of Egyptian blue pigment in the wall painting was investigated with various analytical methods. Visible Induced Luminescence (VIL) imaging was used in-situ in order to map the distribution of the Egyptian blue pigment in the painting. The VIL imaging revealed surprising insights into the understanding of the iconography and the technology of this rare painting. Previously undetected elements of the painting include rays of light that were discovered emerging from the body of Christ and illuminating the other figures in the painting. Although this motif is an important part of the Transfiguration narrative and appears in most of its scenes depicted elsewhere, it had not been previously identified in this painting as it was undetectable by any other inspection technique. Another important result is the identification of Egyptian blue as a common blue pigment used at Shivta during the Byzantine period, when it is considered to be very rare.