Page 1 of 16 Technological Reconstruction of Engraved Wall Plaster: The Inscriptions and Graffiti of the Khallat Es- Siḥrij Reservoir, Israel Aliza van Zuiden¹, Yonah Maor¹, Elisabetta Boaretto², Johanna Regev², Dan Shachar 1 , Nitzan Amitai- Preiss³, Jenny Marcus 1 , Gilad Itach 5 and Yotam Asscher 4,1 * 1 Artifacts Treatment and Conservation Department, Israel Antiquities Authority, Jerusalem 91004, Israel ²DANGOOR Research Accelerator Mass Spectrometry Laboratory, Weizmann Institute of Science, 7610001 Rehovot, Israel ³Hebrew University of Jerusalem , Israel 4 Department of Conservation of Material Culture, School of Archaeology and Maritime Cultures, University of Haifa, Haifa 3498838, Israel 5 Central District, Israel Antiquities Authority, Israel Received Date: April 25, 2023 Published Date: December 05, 2023 ISSN: 2687-8402 DOI: 10.33552/OAJAA.2023.05.000607 Open Access Journal of Archaeology and Anthropology Research Article Copyright © All rights are reserved by Yotam Asscher This work is licensed under Creative Commons Attribution 4.0 License OAJAA.MS.ID.000607. *Corresponding author: Yotam Asscher Department of Conservation of Materi- al Culture, School of Archaeology and Maritime Cultures, University of Haifa, Haifa 3498838, Israel Abstract Wall plaster is an excellent medium to encapsulate inscriptions and art graffiti, since the material is consolidated and relatively resistant to erosion, showing both gypsum and lime plasters were used for writing and engraving artistic features in antiquity. The technological reconstruction of wall plasters that were used for art graffiti and inscriptions could help researchers gain an understanding of their chemistry and preparation processes as a reference for conservation and art studies. To understand if the properties of the base material play a significant role, we characterized the chemical and structural properties of wall plasters showing incisions of crosses, people with raised hands, and Arabic names, in the Khallat es- Siḥrij reservoir near Rosh ha- ‘Ayin, Israel. In this work we show that three different technologies of plaster were used: lime-earth fine grained material, lime-earth course grained material, and lime-crushed ceramics course grained material. The different silicate minerals that were added to the lime influenced the hydraulicity and therefore the hardness of the plasters. The quality of the writings and engravings of features is comparable, indicating that a large variability in plaster technology can be used for inscriptions and art graffiti. This suggests cultural preferences and geographic locations could be the main factor in finding graffiti and inscriptions on wall plasters. Keywords: wall plaster; water reservoir; inscriptions and graffiti; lime-technology; hydraulicity Introduction Plaster is a relatively thin coating of material on rock surfaces, walls, channels or cisterns, either applied for a functional purpose in preventing loss of water or penetration of incoming water, or as a decorative, descriptive or religious purpose including drawings, paintings or texts. There are several techniques of writing and painting on a plaster surface, but it can be distinguished between models in raised or high relief, or in sunken or deep relief, and incised or pressed into a dry surface, or a wet surface. These variations can be accompanied with the incorporation of pigments, and then when painted on a wet plaster surface it is named a fresco technique, while painted on a dry surface with the aid of an organic binder like egg-white or egg-yellow, gum-arabic or an animal glue, it is named secco technique. The plastered surface can