ARTICLE IN PRESS G Model CULHER-3836; No. of Pages 10 Journal of Cultural Heritage xxx (xxxx) xxx–xxx Available online at ScienceDirect www.sciencedirect.com Original article A non-invasive imaging approach for improved assessments on the construction and the condition of historical knotted-pile carpets Ana Serrano a,b,∗ , Suzan Meijer c , Rick R. van Rijn d , Sophia Bethany Coban e , Birgit Reissland a , Erma Hermens c , Kees Joost Batenburg e,f , Maarten van Bommel a,g a Conservation and Restoration of Cultural Heritage, University of Amsterdam, PO Box 94552, 1090 GN, Amsterdam, The Netherlands b Cultural Heritage Agency of the Netherlands (RCE), Cultural Heritage Laboratory, Hobbemastraat 22, 1071 ZC Amsterdam, The Netherlands c The Rijksmuseum Amsterdam, Hobbemastraat 22, 1071 ZC Amsterdam, The Netherlands d Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands e Centrum Wiskunde & Informatica (CWI), Science Park, P.O. Box 94079, 1090 GB Amsterdam, The Netherlands f Leiden Institute of Advanced Computer Science, Niels Bohrweg 1, 2333 CA Leiden, The Netherlands g Van’t Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, PO Box 94157 1090 GD, Amsterdam, The Netherlands i n f o a r t i c l e Historique de l’article : Rec ¸ u le 16 f´ evrier 2020 Accepté le 18 septembre 2020 Disponible sur Internet le xxx Keywords : Knotted-pile Islamic carpets Weaving structure Textile conservation Non-invasive imaging X-radiography Visual spectral comparator A b s t r a c t The appraisal of the design and the weaving structure of Islamic knotted-pile carpets can tell plenty about the context in which they were produced, and the identification of signs of deterioration can help to establish their condition. These are often somewhat imprecise and laborious examinations, especially when considering carpets of large dimensions. Analytical methods that support these disciplines urge further exploration so that improved interpretations can be obtained. An interdisciplinary combination of art history, analytical science and textile conservation aimed, on the one hand, to improve the weaving examination of these complex textile objects – by considering the spin of threads and the ply of yarns; the knot count and density; and the weaving structure of warps, wefts and piles – and on the other, to help their condition assessment – by mapping of damaged areas, old repairs and contaminations. For this purpose, the possibilities and limitations of several non-invasive imaging techniques, namely transmitted, raking or incident visible, ultraviolet (UV) and infrared (IR) illumination through Visual Spectral Comparator (VSC), as well as conventional X-radiography, mammography and (micro) CT scanning, were assessed to support the conventional visual examination of the weaving details and present condition of two 17th-century Safavid knotted-pile carpet fragments. Observation with NUV and NIR imaging with VSC, as well as CT techniques, offered enriching over- views about weaving characteristics, damaged areas or contaminations that were not easily discernible with the naked eye, thus supporting the conventional visual examination. As a result, detailed digital mappings about the technological structure and the condition of the fragments could be obtained in a relatively efficient and accessible way. Moreover, combining art historical identification of the design with the analysis of the weaving structure confirmed that both carpet fragments are border corners that originally belonged to much larger carpets made in the so-called “Indo-Persian” style. The outcome of this interdisciplinary research brings very useful contributions for future art historical and conservation assessments of historical carpets, and it encourages further exploration of imaging techniques in the examination of other textile objects in museums and private collections. © 2020 L’Auteur(s). Publi ´ e par Elsevier Masson SAS. Cet article est publi ´ e en Open Access sous licence CC BY (http://creativecommons.org/licenses/by/4.0/). ∗ Corresponding author at: Conservation and Restoration of Cultural Heritage, University of Amsterdam, PO Box 94552, 1090 GN, Amsterdam, The Netherlands. Adresse e-mail : afaserrano13@gmail.com (A. Serrano). 1. Introduction Knotted-pile carpets have been woven for centuries in Isla- mic territories, and they are today remarkable historical examples of Islamic artistic expression in museums and private collections around the world. Symbols of status and economic prosperity, they ranged from staple floor and wall coverings in peasants’ homes, to esteemed furnishing objects in royal palaces, reflecting the artis- https://doi.org/10.1016/j.culher.2020.09.012 1296-2074/© 2020 The Author(s). Published by Elsevier Masson SAS. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Pour citer cet article : A. Serrano, et al., A non-invasive imaging approach for improved assessments on the construction and the condition of historical knotted-pile carpets, Journal of Cultural Heritage, https://doi.org/10.1016/j.culher.2020.09.012