## 3 Results and Discussion
### Underdrawing  
The infrared reflectography highlighted an extraordinary underdrawing made using a metal point. By analyzing the NIR and SWIR reflectography, it is, in fact, possible to note a continuous greyish line, without interruptions or irregularities and metal points that respond to this characteristic, added to by the fact that it is the most suitable material for working on a rigid support, such as parchment. Figure 4a shows a detail of the SWIR image, \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Spots** & **Color** & **Description** & \multicolumn{2}{l}{**Pigments from the Synergy of Spectroscopic Techniques**} \\ \hline \multicolumn{4}{l}{**Portrait of [PERSON]**} \\ \hline
1 & Flesh & Face, Cheekbone & Calcium-based white pigment, cinnabar, red ochre \\ \hline
2, 5 & Brown & Hair, Eyebrows, Beard & Calcium-based white pigment, under earth, ochres \\ \hline
3 & Light blue & Eyes & Lapis lazuli, calcium carbonate \\ \hline
4 & Reddish & Vein and profile of the eye & Cinnabar \\ \hline
6, 7 & Kuk & Lips & Calcium carbonate, cinnabar, red ochre \\ \hline
8 & White/Light Grey & Ruff & Calcium carbonate \\ \hline
9 & Blue & Armor decorations & Lapis lazuli and lead white on silver \\ \hline
10 & Gold & Armor decorations & Gold \\ \hline
19 & Grey/Black & Dark parchment background & Carbon-based black \\ \hline
20 & White & Point of light and sclera eyes & Calcium carbonate \\ \hline \multicolumn{4}{l}{**Spots on the Pendant with the Santissima Annuziata**} \\ \hline
11 & Gold & Pendant frame & Gold \\ \hline
12 & White & Dove & Lead white \\ \hline
13 & Kuk & Robe & Red ochre, lead white \\ \hline
14 & Hunke & Robe & Red ochre, madder lake, lead white \\ \hline
15, 16 & Hirc Light Blue & Robes & Lapislazuli, lead white \\ \hline
17, 18 & Green & Tent & Green earth, lead white \\ \hline \end{tabular}
\end{table} 
Table 1: Overview of the pigments recognized in the considered painting (see Figure 3 for the collocation of measure points). Figure 3: Portrait of [PERSON] (**left**) and the detail of the Pendant with the Santissima Annuziata (**right**), with the collocation of the measure points. in correspondence to the lips and the nose of [PERSON], where the underdrawing is particularly evident. In the portrait of [PERSON], it is also possible to note the lines of the underdrawing that define the eyes, nose, mouth, and face profile that [PERSON] realized with a freehand drawing. By comparing this with the underdrawing found in [PERSON], it is interesting to note the use of similar material, a metal point, and technique, freehand. Analyzing, in detail, the part of the right ear (Figure 4b-d), we notice a more descriptive stroke in defining the anatomy of this part (Figure 4b), somehow more detailed and more than an outlining in the Portrait of [PERSON] (Figure 4c). In some parts, where the colored brushstrokes are sparser, the drawing is also observable in the visible, but only in macro and micro photographs (Figure 4d). The fine and faint detailed underdrawing is also particularly visible in the detail of the eye of [PERSON] (Figure S1). To help in the visualization of the underdrawing, a post-processing algorithm was applied. The SWIR images were processed to enhance the contrast between underdrawing and background, and the underdrawing lines were extracted. The results are shown in Figure 5, with the sequence of the elaborations applied. This was made trying to distinguish the first preparatory stage where the metal point drawing was traced from the final stage where pigments were applied. Another interesting detail is placed in correspondence with the armor, near the neck of [PERSON] (Figure S2), where the underdrawing is visible under the golden decorations. This result also demonstrates the presence of a detailed underdrawing in areas different from the face. In the case of the armor, considering the geometrical pattern reproduced, the artist used a precise underdrawing as a reference to add and paint the golden and black decorations.