Periodic Reporting for period 1 - PolyCRomA (Polychromy: the meaning of Colour in Roman African statues)
Okres sprawozdawczy: 2020-09-01 do 2022-08-31
Colour is the first object of sight according to ancient thought, thanks to which objects take shape. However, its importance in archaeological works has been underestimated until the 20thcentury, with a consequent progressive loss of colour due to the effects of time, negligence or voluntary removal. There is therefore urgent need to document the surviving traces of colour, to apprehend the works in their original aspect and to grasp the cultural meaning of colour. The study of sculpture polychromies, documenting lost colours by means of a physico-chemical protocol followed by their virtual reconstruction, are an excellent field in which to achieve this aim. However, such studies have not been systematic and remain sporadic, devoted to individual - often exceptional - works of art, or heterogeneous collections. In particular, studies relating to the Roman Imperial period (1st c. BCE-5th c.CE) are even scarcer and almost inexistent for the Western provinces. Proconsular Africa is an ideal territory for investigation of this topic because of the wealth of sculpture, which testifies to the diffusion of Roman culture almost from the 1st CE; because of the abundance of epigraphic and literary sources, as well as representations of the statues in mosaics and paintings, which provide elements for comparison; because Early Christian authors from this geographical territory promoted a theological reflection on statues, in which colour played a role.
The aim of the PolyCRomA project is to investigate on a large scale the meaning of Roman Imperial statue polychromy, studying the collection of the Bardo Museum (Tunis). This collection offers a representative sample because it includes important statues from archaeological Tunisian sites, and many statues - either produced by local workshops or imported from Italian, micro-Asiatic and Greek workshops - on which the colour has been preserved. This offers the possibility of reconstructing the role of colours in the sculptural landscape of this important Western province.
The main objectives are:
1. to document the material traces of colour on sculptures through a physico-chemical analytical protocol (in situ: MSI imaging, video-microscopy, MA-XRF, Raman; on micro-samples: cross section, TOF-SIMS)
2. to interpret the meaning of the colours detected by means of the textual and iconographic sources
The aim of the PolyCRomA project is to investigate on a large scale the meaning of Roman Imperial statue polychromy, studying the collection of the Bardo Museum (Tunis). This collection offers a representative sample because it includes important statues from archaeological Tunisian sites, and many statues - either produced by local workshops or imported from Italian, micro-Asiatic and Greek workshops - on which the colour has been preserved. This offers the possibility of reconstructing the role of colours in the sculptural landscape of this important Western province.
The main objectives are:
1. to document the material traces of colour on sculptures through a physico-chemical analytical protocol (in situ: MSI imaging, video-microscopy, MA-XRF, Raman; on micro-samples: cross section, TOF-SIMS)
2. to interpret the meaning of the colours detected by means of the textual and iconographic sources
The first objective was achieved through three documentation missions to the Bardo museum and the Dougga site. The documentation produced has been interpreted to understand the chromatic visual aspect and the techniques used to create it. The project enabled the construction of the first dataset of polychrome Roman sculptures (115 items) in proconsular Africa, and more generally the largest corpus of Roman polychrome sculptures belonging to a single territory. The second objective was achieved through the study of the photographic and documentary archives of the excavations from which the statues originated, to understand their original visual context, and the study of comparative written and visual sources, to understand the meaning of the colours used.
The main scientific results could then be linked to the understanding of technical and cultural phenomena.
The technical practices have been documented in terms of the palette (earths, minium, sandyx, cinnabar, mimetite, Egyptian blue, organic purple and pink, bone black, lead white, leaf gilding), the rendering of shadows (super-imposing a darker tonality or adding lead or black and blue), the application technique (on a preparatory layer with calcite or gypsum, or directly onto the marble), the binder (Punic wax, casein, egg, "a fresco"). Moreover, in 10 sculptures a restoration of the colour was documented, showing the transition from a realistic use of colour to a more contrasted and less nuanced use.
The colours' appearance aimed to create an illusionistic effect: on the one hand a search to render the human nature of the characters, on the other the desire to imitate precious or meaningful materials. A series of statues, not produced by African workshops, have white skin highlighted in yellow or brownish red, orange lips, eyes marked in blue or black, and blond, brown or chestnut hair. The majority of the other statues analysed are characterized by a polychromy in tones of yellow, orange and red with traces of gilding. A third type consists of statues in which only certain details are coloured, and these contrast with the white of the apparent marble. A fourth type consists on the use of painting to give a prevalent colour peculiar to a deity: for instance, red for Jupiter, brown-black for Isis and Serapis…Cross-referencing the collected visual and written sources and the virtually reconstructed coloured statues, we can begin to understand the cultural value of colour. The colour probably marks the positions of human beings and the gods within society and makes their sphere of influence perceptible to the viewer: in the first type, probably by giving an idea of a physical and living presence; for the second, by imitating gilded bronze or ivory and metal statues, associated with heroic or divine characterisation; for the third, an intermediary status; for the fourth, by hinting at their sphere of influence.
The main scientific results could then be linked to the understanding of technical and cultural phenomena.
The technical practices have been documented in terms of the palette (earths, minium, sandyx, cinnabar, mimetite, Egyptian blue, organic purple and pink, bone black, lead white, leaf gilding), the rendering of shadows (super-imposing a darker tonality or adding lead or black and blue), the application technique (on a preparatory layer with calcite or gypsum, or directly onto the marble), the binder (Punic wax, casein, egg, "a fresco"). Moreover, in 10 sculptures a restoration of the colour was documented, showing the transition from a realistic use of colour to a more contrasted and less nuanced use.
The colours' appearance aimed to create an illusionistic effect: on the one hand a search to render the human nature of the characters, on the other the desire to imitate precious or meaningful materials. A series of statues, not produced by African workshops, have white skin highlighted in yellow or brownish red, orange lips, eyes marked in blue or black, and blond, brown or chestnut hair. The majority of the other statues analysed are characterized by a polychromy in tones of yellow, orange and red with traces of gilding. A third type consists of statues in which only certain details are coloured, and these contrast with the white of the apparent marble. A fourth type consists on the use of painting to give a prevalent colour peculiar to a deity: for instance, red for Jupiter, brown-black for Isis and Serapis…Cross-referencing the collected visual and written sources and the virtually reconstructed coloured statues, we can begin to understand the cultural value of colour. The colour probably marks the positions of human beings and the gods within society and makes their sphere of influence perceptible to the viewer: in the first type, probably by giving an idea of a physical and living presence; for the second, by imitating gilded bronze or ivory and metal statues, associated with heroic or divine characterisation; for the third, an intermediary status; for the fourth, by hinting at their sphere of influence.
The set-up of the analytical protocol is significantly improved in comparison to what has been applied to date in research on this area. First of all, through multiplying the areas analysed microscopically to cover the entire surface of the statue: even where there are no visible colours present, documentation of the presence of colour on statues is significantly increased, and by no means a rare occurrence, but rather the norm. In addition, applying semi-quantitative analyses on large MA-XRF areas rather than point-analysis, and using, for the first time, TOF-SIMS in the analysis of polychromy, enabled one to increase the statistical reliability of the data and its accuracy. The virtual reconstruction, even if hypothetical, is based on a greater number of data and the observation of the techniques employed is more precise.
From the socio-economical point of view, PolycRomA provides a new baseline for future research on polychromy and has introduced to Tunisia – through the collaboration with young and promising Tunisian women curators and an emeritus scientist (F. Béjaoui at INP) – the heritage science approach and a workflow to valorise and preserve the works of art.
The project’s results and activities were disseminated via the website and the Twitter page of the project, and presented at international meetings, seminars and masterclasses, as well as university lectures and secondary-school presentations. A network of scientific collaborations with local institutions and with the most important scientists in the field was established (board of the project: J.S. Ostergaard, P. Liverani, B. Bourgeois). An international workshop, followed by around 150 people, was organised in Liège in October 2021.
The project has exploited the potential of discipline-specific techniques of analysis in a particular context (local scale), producing data capable of contributing to reflections which operate on a broader level (global scale).
Detailed surveys and preliminary measurements were carried out in other European museums (Arles, Departmental Museum; Toulouse, St. Raymond Museum; Brussels and Mariemont, Royal museums of Belgium; Milan, Archaeological Museum).
From the socio-economical point of view, PolycRomA provides a new baseline for future research on polychromy and has introduced to Tunisia – through the collaboration with young and promising Tunisian women curators and an emeritus scientist (F. Béjaoui at INP) – the heritage science approach and a workflow to valorise and preserve the works of art.
The project’s results and activities were disseminated via the website and the Twitter page of the project, and presented at international meetings, seminars and masterclasses, as well as university lectures and secondary-school presentations. A network of scientific collaborations with local institutions and with the most important scientists in the field was established (board of the project: J.S. Ostergaard, P. Liverani, B. Bourgeois). An international workshop, followed by around 150 people, was organised in Liège in October 2021.
The project has exploited the potential of discipline-specific techniques of analysis in a particular context (local scale), producing data capable of contributing to reflections which operate on a broader level (global scale).
Detailed surveys and preliminary measurements were carried out in other European museums (Arles, Departmental Museum; Toulouse, St. Raymond Museum; Brussels and Mariemont, Royal museums of Belgium; Milan, Archaeological Museum).