*3.3. Computerized Tomography*

The tomographic images showed the original structure of the sculpture and some modifications (Figure 3). The body is hollowed and was constructed initially with a twohalf cast (Figure 3c) to obtain a general shape. The artist modeled the volumes over the paper silhouette, first with debarked maize stems and later with maize stem paste.

**Figure 3.** (**a**) Detail of the sculpture, the dashed lines in color indicate the different areas of the tomograms; (**b**) Axial tomogram of the shoulder areas, the image shows the articulation system (A) and the wooden elements used to insert the head of the sculpture (W); (**c**) Axial tomogram shows the hollowed structure, the paper layer (P) obtained using a two-half mold; the red arrow shows the union between the two halves obtained from the mold. The wooden elements used to reinforce the arms and insert the wooden hands are marked with W.

The upper head part (i.e., the cranial vault) was modified by adding three wooden fragments pasted together (Figure S3b,c). Additionally, the space between the head and hair (which was modeled using gypsum as suggested by SEM-EDX analysis, data not showed) suggests it is a modification. Small metallic nails (approximately 60) fixed it to the sculpture head (Figure S3a).

The tomographic study also allowed us to understand the shoulders articulation system (Figure 3b), it is a "*galleta*" or "*gozne de paleta*" system (similar to a hinge), done using a woodblock cut in the external extremity to create a space; another wooden element from the inside of the arm was inserted in the middle of the woodblock and fixed with a linchpin (Figure S3a). This particular articulation system was already used in Spanish sculptures in the 16th century [46]; however, previous studies on New Spain sculptures suggest that the "*galleta*" system was used after the 18th century, while the most common articulation system during the 16th century was spherical [47]. In light of this, the articulation system was probably substituted, which is reasonable considering the possible damage produced by the constant use.

Particularly in the loincloth area, we observed a hidden perforation on the left side (Figure 4b) that was probably used to insert a ribbon (today lost) when the sculpture was placed on the cross, as several paintings show, for example, *El Señor de Santa Teresa* (1760) by Francisco Antonio Vallejo (1722–1785) or the *El Señor de Chalma* (1719) by José de Mora (1642–1724), both today at the Museo Nacional de Arte in Mexico City.

**Figure 4.** (**a**) Detail of the lower part of the sculpture, the dashed lines in color indicate the different areas of the tomograms; (**b**) Axial tomogram of the loincloth, the image shows a possible hold to insert a removable ribbon (marked with a red dashed circle), in the same region the separation of the two halves of the paper layer is shown; (**c**) The axial tomogram shows the wooden elements that reinforce the knees, the inset shows the circumference of the debarked maize (DM) stems and the maize stem paste (MSP) used to obtain the volumes; (**d**) Sagittal tomogram that shows the hollowed structure, the paper layer (P), and the wooden elements (W) used to reinforce the knees and to insert the feet.

In addition, the CT images showed the technical knowledge of the artist who used resistant materials in the areas where mechanical stress concentrates. The hands and feet were carved in wood (probably *colorín* to avoid increasing the weight) and some wooden elements to reinforce the neck, the arms (Figure 3b,d), and the legs (Figure 4d), as well as for fixing the hands and feet were inserted (Figure 4d). Several wooden elements reinforced the knees (Figure 4c,d).
