## 5 Discussion  
This work focused on the possibility of updating, integrating, and initiating analytic studies on Near East archaeological artefacts. As seen before, clay tablets from Umma enclosed sensitive and extremely important information to be documented and preserved. One of the novelties of this project is related to the possibility of updating seal impression studies, especially to extract the figurative apparatuses as well as to integrate previous studies. Accurate scanning, highly detailed 3D outputs, and MSII analysis could contribute to updating and expanding the investigation and interpretation of sealing procedures.  
At the same time, the post-processing analysis of sealings could initiate new semantic connections regarding scribes.  
As we have seen, the seal impression of MAT 689 was originally documented by [PERSON] [12; 13], but a deeper and innovative analysis via highly detailed 3D scanning has permitted significant integration of the proposed figurative apparatus.  
The extraction of seal impression reveals the methodology behind the marking step: as reported on the tablet MAT 689, sealings were made by both rolling the cylindric seal and impressing a specific area of the textual and figurative apparatus.  
Another innovative aspect of this work is related to the possibility of extracting metrically accurate biometric data from clay tablets: After the 3D reconstruction, the MSII filter contributes to extracting and enhancing nearly visible sensitive information from the surface. Fingerprint impressions of scribes can be investigated with micrometric precision, 3D resolution, and an ad hoc post-processing operation. These data may be fundamental for analysing the people behind the objects: In this regard, the age estimation analysis [26; 27; 28] and multiple fingerprint matches via fingerprint typology and metric analysis are necessary parameters for identifying the scribes who wrote these documents. However, documenting sub-millimetric details on archaeological finds is always challenging. In the last fifteen years, the 3D documentation method has been designed. Portable structured-light scanners have accelerated the digitization process of risky heritage assets as well as archaeological artefacts permanently preserved in museums.  
This research project is also intended to highlight the possibilities of 3D scanning through portable solutions: the Artec Space Spider is revealed as a flexible and smart instrument for quick scanning sessions performed on site (museums). For large projects, a rapid scanning session is currently a much-needed operation. Depending on details and dimensions, the structured-light scanning and early reconstruction of cuneiform tablets requires about 10-15 min. By using other methodologies and instruments, the acquisition and processing time could significantly change: For example, photogrammetric survey is quite swift, but requires time-consuming processing (about 20-30 min, including image masking, image orientation, tie-points extraction, dense cloud, mesh creation, cleaning operations, and texture mapping).  
In this regard, the Space Spider sensor, with a 3D point accuracy of 0.05 mm, is an extremely valuable instrument for capturing micrometric details on the surfaces of tablets.  
Of course, other commercial scanners like Artec Micro [15], with a 0.01 mm 3D point accuracy and a 0.029 mm 3D resolution, could perform better; however, this solution is not completely portable or flexible.