TY - JOUR A1 - Steger, Simon A1 - Stege, H. A1 - Bretz, S. A1 - Hahn, Oliver ED - Tomasin, P. T1 - Disclosing glittering and sparkling effects in 20th-century reverse glass paintings: a study of metallic pigments and metal foils by means of in situ XRF and DRIFTS analysis N2 - This work presents a spectroscopic study of metallic pigments and metal foils used in reverse glass paintings that were created between 1912 and 1954. Metallic pigments induce a notable sparkling effect by means of the lateral incidence of light, whereas metal foils enhance the gloss and create a glittering effect when the painting is viewed in reflected light. Both effects were desired features especially in modern reverse paintings on glass and applied by artists in manifold creative manner. The paper gives an overview on the composition of the metalfoils and metal pigments in 14 works as determined in situ by X-ray spectrometry. Metal foils made of tin, brass, aluminium and silver were found in nine paintings. Gold imitating Cu-Zn pigments in different hues and with various Cu/Zn net intensity ratios were recorded for six paintings. Silvery pigments were identified mainly as Al pigments, but also as Cu-Zn-Ni alloy in one case. Other uncommon metallic pigments were detected in Arlequin vindicatif (c. 1925) by Floris Jespers, who used not only Cu-Zn and Al pigments, but also brownish Cu and Cu-Zn-Sn pigments. Non-invasive diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) was used to classify the binding media of the metallic pigments. Drying oil and natural resin probably mixed with oil were the most common binding media. A polysaccharide-based binder was found in the silvery Cu-Zn-Ni pigment of Ohne Titel (1954) by Marianne Uhlenhuth. KW - Archaeometry KW - Non-invasive analysis KW - Reverse paintings on glass PY - 2020 DO - https://doi.org/10.1016/j.culher.2020.11.008 SN - 1296-2074 VL - 48 SP - 196 EP - 204 PB - Elsevier Masson SAS CY - Amsterdam AN - OPUS4-54428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Rabin, Ira A1 - Hahn, Oliver ED - Michel, C. ED - Friedrich, M. T1 - Detection of Fakes: The Merits and Limits of Non-Invasive Materials Analysis N2 - This paper addresses the sensitive issue of authenticating unprovenanced manuscripts of high monetary value to certify they are genuine. Over the last decade, the popularity of material studies of manuscripts using non-destructive testing (NDT) has increased enormously. These studies are held in especially high esteem in the case of suspicious writings due to the methodological rigour they are reputed to contribute to debate. We would like to stress that materials analysis alone cannot prove that an object is genuine. Unfortunately, audiences with a humanities background often tend to disregard the technical details and treat any published interpretation of instrumental analysis as an objective finding. Four examples are outlined here to illustrate what questionable contributions the natural sciences can make in describing manuscripts that have actually been forged. KW - Fakes KW - Non-invasive analysis KW - Limitations PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517202 SN - 978-3-11-071422-7 DO - https://doi.org/10.1515/9783110714333 SN - 2365-9696 VL - 20 SP - 281 EP - 290 PB - Walter de Gruyter GmbH CY - Berlin/Boston AN - OPUS4-51720 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Hahn, Oliver A1 - Golle, U. A1 - Wintermann, Carsten A1 - Laurenza, D. ED - Quenzer, J. B. T1 - Scientific Analysis of Leonardo’s Manuscript with Anatomic Drawings and Notes N2 - In this paper, we discuss the importance of scientifically investigating cultural artefacts in a non-invasive way. Taking as test case Leonardo da Vinci’s Manuscript with anatomic drawings and notes, which is stored in Weimar, we clarify fundamental steps in the chronology of this folio. By means of microscopy, infrared reflectography, UV photography, and X-ray fluorescence analysis, we were able to identify various types of sketching material and several varieties of iron gall ink. For his sketches, Leonardo used two different sketching tools, a lead pencil and a graphite pencil, as well as several types of ink for developing these sketches into drawings. With regard to ink, it is important to observe that there is no difference between the ink Leonardo used for drawing and the ink he used for writing text. Based on the materials analysed, we suggest a chronology for the creation of this unique folio. KW - Archaeometry KW - Non-invasive analysis KW - Drawings KW - Leonardo da Vinci PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543460 SN - 978-3-11-074545-0 DO - https://doi.org/10.1515/9783110753301-011 VL - 25 SP - 213 EP - 228 PB - Walter de Gruyter GmbH CY - Berlin/Boston AN - OPUS4-54346 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -