2.1.1. Binding Media ure 2, from which it was possible to find common characteristics associated with the

FORS SWIR spectra from regions with different colors of the paint are shown in Figure 2, from which it was possible to find common characteristics associated with the binder. binder.

**Figure 2.** FORS spectra from representative regions corresponding to different colors. Principal features related with binder media are indicated. Spectra corresponding numbers are indicated in Ap-**Figure 2.** FORS spectra from representative regions corresponding to different colors. Principal features related with binder media are indicated. Spectra corresponding numbers are indicated in Appendix A Figures A1 and A2 general diagram.

In Figure 2, we can observe spectral features related to lipids on 1729 nm, associated

with the first overtone of the stretching mode from the methilenic group [2νୟCHଶ], and

combination bands from stretching ( asymmetric and ௦ symmetric) and bending (δ)

In Figure 2, we can observe spectral features related to lipids on 1729 nm, associated with the first overtone of the stretching mode from the methilenic group [2*νa*CH2], and combination bands from stretching (*ν<sup>a</sup>* asymmetric and *ν<sup>s</sup>* symmetric) and bending (δ) modes on 2308 nm, [(*ν<sup>a</sup>* + δ)CH2], and 2349 nm [(*ν<sup>s</sup>* + δ)CH2]. Such characteristics have been noticed in the works by Pérez et al. [7], and Dooley et al. [18]. These absorption bands are common all over the paint, and their presence indicates the knowledge of the drying oil to bind the pigments.
