**5. Conclusions**

In this study, a whole spectroscopic approach involving FORS and SERS spectroscopies was employed in order to identify different synthetic dyes used for the manufacturing of *Tholu Bommalu* leather puppets from the 1970s. The two techniques were directly applied on sampling stubbons, used for the extraction of the dyes from the objects of interest. This approach resulted successful for the identification of coloring molecules in some parts of the puppets: indeed, the data separately obtained from the two techniques reciprocally confirmed the attributions (Malachite Green and Crystal/Methyl Violet for the D816-7 sample, Rhodamine B for D817-2). In other cases (D816-4, D817-4) the use of SERS after FORS analyses provided further data and allowed to draw a richer picture on the composition of the materials: for the D816-4 sample, Rhodamine B was found in probable mixture with Eosin Y, while for the D817-4 sample, a combination of an azo dye for the yellow part and Crystal/Methyl Violet for the dark decorations was hypothesized. Finally, in the case of some areas (the D816-5, D816-9, and D816-15 samples), the analyses provided preliminary hypotheses about the colorants, which are likely present in mixture. The achieved results are of paramount importance in the perspective of selecting the proper methodology for a consequent separative analysis, which could confirm the results obtained from the spectroscopic approach and solve the doubts regarding the whole composition of complex mixtures of dyes. Moreover, the reported experiments confirmed the transition from natural dyes to synthetic ones in the manufacturing of *Tholu Bommalu* puppets.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10 .3390/heritage4030101/s1, Figure S1: (a) Visible light reflectance spectrum obtained for the sample D816-4 with the corresponding first derivative (red lines highlight the inflection points) and (b) related apparent absorption spectrum (background subtracted); Figure S2: (a) Visible light reflectance spectrum obtained for the sample D816-4 with the corresponding first derivative (red lines highlight the inflection points) and (b) related apparent absorption spectrum (background subtracted); Figure S3: (a) Visible light reflectance spectrum obtained for the sample D816-5 with the corresponding first derivative (red lines highlight the inflection points) and (b) related apparent absorption spectrum (background subtracted); Figure S4: (a) Visible light reflectance spectrum obtained for the sample D816-15 with the corresponding first derivative (red lines highlight the inflection points) and (b) related apparent absorption spectrum (background subtracted); Figure S5: (a) Visible light reflectance spectrum obtained for the sample D817-4 with the corresponding first derivative (red lines highlight the inflection points) and (b) related apparent absorption spectrum (background subtracted); Figure S6: Conventional Raman spectra obtained for the samples in the range 350–1050 cm−<sup>1</sup> (top) and in the range 1050-1750 cm−<sup>1</sup> (bottom); Figure S7: SERS spectrum obtained for D816-9 sample.

**Author Contributions:** Conceptualization: A.C., I.S., A.N., B.G. and M.B.; investigation: A.C. (Raman and SERS spectra, interpretation of FORS spectra), A.B. (FORS spectra), A.N. (interpretation of FORS spectra); resources, P.P. and M.B.; main writing—preparation of original draft, A.C., I.S. and G.D.; writing—review and editing, A.C., I.S., G.D. and F.R.; supervision: R.C., P.P. and M.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** We are grateful to the International Puppets Museum "Antonio Pasqualino" in Palermo, Sicily, Italy, for the granted access to the historical objects and the collaboration on this research.

**Conflicts of Interest:** The authors declare no conflict of interest.
