Characterization of contemporary artworks made on photosensitized canvas by means of optical microscopy and micro-Raman spectroscopy techniques

Abstract

Contemporary artists experimented with a wide range of techniques as it is photography, combined with other materials so as to create images on various surfaces. Nikos Kessanlis (1930–2004), an eminent Greek artist, used photographic and mechanical techniques, involving the application of a photosensitive emulsion on different supports for his artistic creations. This photomechanical technique is called alternative printing.The present study examines a series made by Kessanlis in 1999–2000, composed of eleven panels of photosensitized canvases with the scope to identify the materials used by the artist (canvas, primer, photographic emulsion, protective layer), to understand the artist’s technique and to document the panels overall condition. The series is examined using non-invasive techniques (portable digital optical microscope) and analysis of micro-samples by–micro-Raman spectrometry.Micro-Raman analysis results identified the support, as canvas made by cotton and jute, the primer layer as a combination of titanium white and calcium carbonate and finally the photosensitized layer, as a gelatin silver chloride emulsion. Also further compounds are detected such is silver sulfide, related to the photosensitized emulsion deterioration and soot and lignin, related to the impure environment (air flow inside the metro station) where the series are on display for the last twenty years (Athens metro station).Finally, measurements of air temperature and relative humidity are also performed for a short period near the panels so as to evaluate the environmental conditions of the area. The results have shown extreme daily fluctuations of both factors, characterized by “cycling” that could be related to mechanical and chemical deterioration factors affecting the artwork condition.