**1. Introduction**

*Tholu Bommalata* is the traditional shadow theatre of the Telugu Indian states of Andhra Pradesh, Telangana, and Karnataka. The expression literally means "dance of leather puppets", from "atta", meaning dance, and "*Tholu Bommalu*", meaning leather puppets [1]. According to the literature, the use of these puppets dates back to 200 B.C. under the dynasty of Satavahana [2]. To realize a shadow theatre, puppeteers press the dolls behind a backlit screen, so the audience only see dancing shadows [3]. The main areas of storytelling are the Indian epics of *Ramayana ¯* and *Mahabarata,* and the sacred Hindu texts ¯ *Pura¯n. a,* even though nowadays, the epics are no longer narrated, replaced by contemporary themes such as reforestation or family life scenes. Dolls can be moved from anyone, but only a skillful *sutradhar* (literally "wire mover") can give them life. He is the leader of a familiar-run troupe, where everyone has a specific role: dancer, singer, narrator, and actor [4]. In all the Indian traditional puppet theatres, *Tholu Bommalu* are the biggest ones

D'Agostino, G.; Giambra, B.; Bosi, A.; Ripanti, F.; Nucara, A.; Postorino, P.; Curini, R.; Bruno, M. Dyes of a Shadow Theatre: Investigating *Tholu Bommalu* Indian Puppets through a Highly Sensitive Multi-Spectroscopic Approach. *Heritage* **2021**, *4*, 1807–1820. https://doi.org/10.3390/ heritage4030101

**Citation:** Ciccola, A.; Serafini, I.;

Academic Editor: Diego Tamburini

Received: 30 June 2021 Accepted: 3 August 2021 Published: 16 August 2021

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**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

(120–180 cm height), and those with the highest mobility have joints along the neck, arms, and legs [5]. Every puppet is made of leather, the origin of which was not arbitrary: at the beginning, deer was used to represent Gods, goat for saints or common people, and buffalo for demons, while today goat skin is the most used. Dolls are charged with an enormous spiritual value. Indeed, they are made of leather, an impure material for Indians, and, thus, they need a purification rite to represent sacred characters: several weeks before the performance, plenty of rituals are made to offer the puppets to Gods. At the end of each performance, people let them go to the banks of Gange River, as a real funeral [1]. According to sources [3], the first puppeteers used to paint *Tholu Bommalu* with natural colors mixed with water, later replaced by synthetic dyes. Today, *Tholu Bommalata* is a kind of dying art: fifty years ago, more than 180 troupes were active in 30 different Indian districts; today there are only 9.

Here, we studied the two *Tholu Bommalu* (Figure 1*)*, made in 1978 by the Ramana Murthy theatre, which are part of a 173-artifact collection stored at the International Puppets Museum "Antonio Pasqualino" in Palermo, Sicily, Italy. They represent Prince Rama and ¯ Princess S¯ıta, the main characters of ¯ *Ramayana. ¯*

**Figure 1.** Sampling areas from *Tholu Bommalu* of Rama ( ¯ **a**) and S¯ıta ( ¯ **b**).

The Rama puppet (Figure ¯ 1a), as seventh reincarnation of Visnu, is pictured in profile and with blue skin: both aspects represent divine characters. It also has almond-shaped eyes, a big nose, and thin lips; it is entirely decorated with rich jewels that underline his social status, everything made with pink, red, blue, violet, and black dyes. Both arms and legs were probably added to the puppet in a second stage, replacing missing parts: they indeed show different decorations and colors—blue and violet—than the rest of the puppet.

The Princess S¯ıta puppet (Figure ¯ 1b), as a not divine character, is pictured frontally, and entirely made with black, red, and yellow dyes. As with the other puppet, it has almondshaped eyes, a big nose, but thicker lips. She wears a dress full of flower decorations and rings in her hands and nose. They both wear *tilaka* on their forehead, a sacred sign, the mark of God and symbol that purifies the body.

The S¯ıta and R ¯ ama ¯ *Tholu Bommalu* are made of goat skin, identified by the Globe Institute of Copenhagen using ZooMS, short for Zoo Archaeology by Mass Spectrometry. It is a technique that uses the slow evolution of collagen as a molecular barcode to read the identity of leather or bones. The method uses a well-established approach, peptide mass fingerprinting, allied to high throughput Time of Flight Mass Spectrometry. Samples are

identified by differences in the mass of the peptides, which arise as a result of sequence differences between species [6]. Each part of the body is a separated piece of leather, one linked to the other by a thin string, observed and identified as cotton by a light microscope [7]. Between the junctions, there is a little piece of leather that make this part more resistant in the points of greatest fragility. To be held by *suthradar*, they are assembled on a wooden stick, recognized as cane wood by light microscope observation [8]. They are full of holes of different shapes and sizes marking every decoration line: light can pass through them during the performance, producing an incredible effect of lights and shadows. Preparatory drawing is carved on one side of the leather, while both sides are colored with a translucent effect. There is a similar varnish layer upon the surface on both the sides: according to the literature [3], it could be neem or coconut oil, used by puppeteers to preserve dolls from time damages.

As mentioned above, several colors were used to achieve the brilliant shades present in the puppets. During the conservation study of these objects, it was noticed that the related colorants were sensitive to water in terms of solubility. Consequently, it was evaluated that organic dyes could be present and their identification could be very interesting: with reference to the recent origin of the dolls, synthetic dyes could be used and their characterization could confirm the transition from natural dyes to synthetic ones in *Tholu Bommalata* production. For this aim, a multi-technical approach was dedicated to their identification and characterization. Visible light Fiber Optic Reflectance Spectroscopy [9–12], coupled to an optical microscope (micro-FORS), was employed to obtain preliminary information about the class of dyes: reflectance spectra were acquired directly on stubbons used to sample to dyes during the conservation treatments. The same samples were then analyzed with Surface Enhanced Raman Scattering (SERS) [13–18], which is based on the great enhancement of the Raman signal of an analyte in close proximity of a metal nanostructured substrate, allowing it to obtain vibrational spectra that, otherwise, would be affected by a dramatic fluorescence background. In the last decades, SERS spectroscopy has showed its great analytical potentiality [19], and it is nowadays increasingly used for the characterization of colorants in art objects. Starting from its first application on ancient textiles [20], this technique has been used for the identification of natural and synthetic dyes in paintings and dyed objects [13,21,22]. The evolution from simple metal colloids to nanostructured SERS substrates [23–28] and metal-nanoparticles loaded sampling devices [29–34] provided several analytical strategies, which were exploited for the detection of both natural and synthetic dyes [14,16,18,23,35–38]. The main advantage of SERS is highly represented by high sensitivity, which is in charge for lower detection limit than High Performance Liquid Chromatography, while the main drawback is the low reproducibility which could derive from local interaction between the nanostructure and mixtures of analytes through different functional groups.

Here, the combination of SERS and FORS data allowed to individuate several synthetic dyes used for the manufacturing of these objects and provided new data for consequent further analyses.
