# Enhancing 3D-Printed Clay Models for Heritage Restoration Through 3D Scanning
### 3D-Printing Clay  
In contrast to the application in medicine, robotics or aerospace components of some 3D printed materials, clay is gaining increasing relevance in various fields, from art and dentistry to building construction and conservation of cultural heritage [22]. This innovative technique allows for the creation of complex objects and structures with high precision, using a traditional material like clay [23]. The conservation of cultural heritage and the creation of artistic works require methods that enable the precise and detailed reproduction of objects and structures [24]. Traditionally, working with clay has been a manual practice that demands significant skills and time. Additionally, the preservation of historical objects made of clay presents specific challenges, such as the need to restore damaged pieces without compromising their original integrity [25]. There are several commercial techniques for ceramic restoration beyond 3D printing. One is cold restoration, using epoxy resins to bond broken fragments, followed by colour retouching [26]. Another is slip casting, where liquid clay is poured into plaster molds to replicate ceramic pieces [27]. Laser cleaning is also used to clean ceramics without damage [28]. Additionally, _Kintusqi_, a Japanese method but considered an art itself [29], repairs cracks with lacquer and gold powder, highlighting imperfections as part of the piece's history. Each method is suited to the condition and nature of the ceramic piece. In this context, 3D printing with clay has emerged as a revolutionary solution, facilitating both the creation and restoration of these objects with high precision and efficiency [30]. It even allows a precise control of the level of detail of the replicas of original pieces that need to be replaced or completed, which is in line with the guidelines of international cultural heritage restoration legislation [31; 32; 33; 34]. Furthermore, Article 10 of the same regulatory document states: 'When traditional techniques prove inadequate, the consolidation of a monument may be ensured by making use of all modern construction and conservation techniques whose effectiveness has been scientifically proven and guaranteed by experience' [35]. In recent years, advancements have been made in the application of 3D printing technology for materials such as clay [36; 37; 38] and cement [39; 40; 41], particularly in the fields of construction and heritage conservation. Several studies have explored the use of cement-based materials for large-scale 3D printing, highlighting the benefits of reduced construction time and material waste [42]. Similarly, research on 3D printing with clay has demonstrated its potential for creating sustainable, intricate architectural elements and cultural heritage reproductions [43; 44]. These works emphasize the adaptability of both clay and cement in additive manufacturing processes [45], offering diverse applications ranging from modern construction to the preservation of historical artefacts. 3D printing with clay is an additive manufacturing process that allows for the creation of three-dimensional objects layer by layer from digital models [46]. It has significant applications in the conservation of cultural heritage [47]. Conservators can use this technology to recreate missing or damaged parts of historical clay artefacts, ensuring that the replicas are faithful to the original. Moreover, 3D printing allows for the creation of exact copies of historical objects that can be studied and exhibited without the risk of damaging the original pieces [48]. This not only helps preserve the original artefacts but also facilitates their accessibility and study by researchers. The early studies on 3D printing with clay focused on adapting conventional 3D printers to work with ceramic materials. [PERSON] [49] in 2011 pioneered the integration of mortar extrusion into 3D printing systems, addressing challenges related to material rheology and the structural stability of printed objects [50].