<p><strong>Abstract.</strong> <i>Az Infinitum</i> &amp;ndash; <i>Azulejo Referencing and Indexation System</i> may be briefly defined as a work tool combining Art History’s traditional methods with the use of digital technologies, in order to create a system designed to document, catalogue and index all the tile decorations produced and applied in Portugal since the late 15^th century and still found in their original locations. By highlighting the potentialities of <i>Az Infinitum</i> and by describing its data structure and the procedures used to collect and upload information, the present article proposes a reassessment of the project in light of these parameters, as well as a discussion of future developments. Moreover, it aims to clarify the link between the norms followed within the system and the ones used internationally. This link reflects the aim of integrating the system within previously developed structures, without losing sight of the specificities of a <i>hybrid</i> form of heritage, whose documentation must be adapted in different ways. Such a need has led to the development of specific data structures, designed to meet the unique characteristics of patterned tile decorations.</p>

The present article focuses on the cataloguing Baroque azulejo frames and aims to explain the methodology of the project as well as the expected results. I will discuss the importance of cataloguing and the system used – Az Infinitum – Azulejo Indexation and Referencing System (redeazulejo.fl.ul.pt/pesquisa-az). I will also address the different cataloguing options, some of which came from conclusions drawn during the actual cataloguing work. I will also assess the benefits offered by this kind of systematisation for the study of azulejos and related decorative systems within the context of the Baroque concept of artistic totality, which is typical of Portuguese interiors from the last decades of the 17th century to the first decades of the following century.

This study reports the mineralogical and chemical characterization of the ceramic body of tiles created by Gabriel del Barco, an important tile painter in Lisbon from the 17th century. Six tile panels were studied: four are signed and two are attributed to the painter. The results obtained from the signed panels revealed that the samples have almost the same characteristics, with a magnesium‐rich phase, meaning that the artist, or the pottery where the tiles were made, kept to the same manufacturing procedure over some time. In contrast to this, the results of samples from the masterpiece Vista de Lisboa showed some heterogeneity, as two patterns were observed. However, one of these patterns matches with the one observed in the signed tile panels. Although a more detailed study still needs to be done, these findings, together with historical sources linked to painting characteristics, suggest that Gabriel del Barco was also the author of the non‐signed tiles.