Godišnjak Fakulteta bezbednosti (Jan 2018)
The scientific examination of works of art on paper
Abstract
One of the most profitable forms of criminal activity is the forgery of works of art, where huge profits are earned on auctions and on the black art market. In private collections, galleries and museums, there is certainly a large number of undiscovered forged artworks whose authenticity is to be determined. Much of the authentication process does not belong to forensics, because art historians and art connoisseurs most often made conclusions about authenticity. Later examinations found that 40% of the works of art were of questionable authenticity; which points to the need for a scientific analysis of works of art, and that the forensic approach to authentication is replaced by experts or experts in the history of art. The need for expertise of documents and works of art on paper usually occurs when the content, origin or presentation of the circumstances under which the work is made constitutes a serious suspicion of its authenticity. The expertise of works of art on paper represent a criminal and judicial examination of works of art where paper is used for the substrate, and in the works of art there are watercolors, pastels, graphic prints, drawings (pencil, ink wash paint, ink), maps and plans, and many other combined techniques. The scientific study of art works on paper uses tools from very simple to state-of-the-art analytical instruments which provide detailed and accurate information about work of art on paper. The scientific study of works of art on paper shares common objectives with the technical studies of any work of art. Artifacts are examined in order to answer art historical questions about the origin of a work, namely, where, when, and by whom a work was created. The main components that make up an artwork on paper are paper (paper substrate), pigments and colors, various types of inks, and other materials used to create an artwork (such as charcoal, pens, various media, combined techniques, etc.). The expert must have the necessary knowledge of the components that make up an artwork on paper; to know the types of paper, to differentiate painting techniques; to know perfectly about the components from that make up the work of art (composition, types of production and types of paper, composition and types of pigments, composition and types of inks, tools used for workmanship, etc.). First, simple methods are used, such as the detailed study of the components of the painting (identification of paper, paint, ink, pigment, etc.). Subsequently, physical non-destructive methods are used that do not impair the tested material: use of different types of microscopes (stereo microscope, polarization microscope, fluorescence microscopy); magnifying glasses; types of invisible rays (ultraviolet rays, infrared rays, X-rays), neutron activation analysis, X-ray fluorescence analysis, Raman spectroscopy, and investigative photography. Destructive methods damage the material being analyzed. Destructive methods include chemical analysis, chromatography (Liquid Chromatography, Gas Chromatography, Thin-Layer Chromatography), electrophoresis, infrared spectrophotometry, etc. These methods are highly avoided and are used only in extreme as ultimate necessity, in the case where the results obtained previously are unsatisfactory and with insufficient information. Each of these methods has a different working principle and gives us different information about the subject being analyzed, and the expert must have a basic knowledge of chemistry in order to understand the working principle of these analyzes and to know what kind of information they provide.
