16 th – 17 th century filigrana glass found in Portugal: some preliminary observations Francisca Pulido Valente 1,2 , Inês Coutinho 1,2 , Teresa Medici* 2 , Márcia Vilarigues 1,2 1 Department of Conservation and Restoration, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal 2 Research Unit VICARTE - "Vidro e Cerâmica para as Artes", Campus Caparica, 2829-516 Caparica, Portugal Abstract The present contribution addresses the study of more than 150 glass fragments decorated with filigrana technique coming from four archaeological excavations in Portugal: Santa Clara-a-Velha Monastery in Coimbra, Santana Convent and Largo do Chafariz de Dentro in Lisbon, and São João de Tarouca Monastery in Lamego. The fragments show a wide use of different type of canes - canna a fili, canna a rete, canna a ballotini and canna mista - according to the terminology used by Kitty Laméris (2012). The presence of filigrana a reticello and objects made in one and two layers are also evident. It is possible to determine a large variation in (1) quality of materials, (2) colours, with filigrana made with clear and transparent glass, or with greyish or even greenish glass, (3) quality of the technique, with the occurrence of some pieces where the termination of the canes was not removed, and with variations in the space between the applied canes in the same fragment. This paper aims at providing some preliminary observations regarding these fragments, which are being studied as part of a larger project. Introduction Although considerable research has been devoted to façon-de-Venise glass, less attention has been paid to the systematic and transdisciplinary study of the filigrana technique. Few analytical works focused exclusively on filigrana glass (Ramos et al., 2008; Rohanová and Sedláčková, 2015; Wouters and Fontaine, 2007) while the majority of the papers published so far only include filigrana glass among Venetian or façon-de- Venise objects (Coutinho et al., 2016; Countinho 2016; Hulst and Kunicki-Goldfinger, 2015; Janssens, 2013; Jackson, 2006; Mortimer, 1995; Raedt at al., 2001; Raedt at al., 1998; Verità, 2013). In the frame of a PhD research project on technological development, circulation, and use of Venetian and façon de Venise decoration techniques in Portugal during the 16th and the 17th centuries, more than 150 filigrana glass fragments are currently studied. They come from four archaeological sites: Santa Clara-a-Velha Monastery in Coimbra (SCV), Santana Convent (LSC) and Largo do Chafariz de Dentro (LCD) in Lisbon, and São João de Tarouca Monastery (SJT) in Lamego. The selection has been made on the basis of the results of previous studies and it is a good representation of the different filigrana types circulating in Portugal between the end of the 16 th and the middle of the 17 th Century (Medici 2014; Coutinho et al., 2016; Countinho 2016).