Identification of Lithol Red Synthetic Organic Pigment Reveals the Cause of Paint Layer Degradation on the Lazar Vozarevi? Painting “Untitled” with Copper Plates

摘要

Out of a total of 56 paintings in the collection of the Lazar Vozarevi? Gallery in Sremska Mitrovica, only one Lazar Vozarevi? painting from 1961, titled Untitled, has been subject to atypical degradation that has resulted in damage of completely atypical appearance. Such a problem had never before been noticed in Yugoslavian paintings of the 20th century. Discolored areas were found in various locations on the paint layer of the painting Untitled (especially on the lower and central parts of the painting), which disturbed the visual experience of the artistic work. To discover the cause of this discoloration, the composition of the paint layer was investigated, with the assumption that the true cause of degradation was hidden therein. Moreover, this painting belongs to a specific period in Vozarevi?s activity, characterized by the use of non-traditional painting materials. To identify pigments from the highly degraded painting Untitled, scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM/EDS) and micro-Raman spectroscopy were applied. Lithol red, a synthetic organic pigment known to give paintings a red tone, was identified as the main reason for the paintings degradation. Lithol red is not only highly light-sensitive but is also chemically unstable, toxic, and sensitive to heat.