Technical report on the conservation status of the ‘Three Iberian Ladies’

The interdisciplinary working group created by the Ministry of Culture and Sport, at the request of the Directorate General of Cultural Heritage and Fine Arts, to analyse the conservation status of the ‘Three Iberian Ladies’ of the National Archaeological Museum (MAN) - the Dama de Elche, the Dama de Baza and the Dama del Cerro de los Santos - has completed its technical report on the conservation status of these pieces. The study, in which staff from the MAN, the Subdirectorate General of State Museums and the Spanish Cultural Heritage Institute (IPCE) participated, continues and reinforces the work carried out in previous years, implementing new control and conservation tools.

Although each piece has been studied individually and in detail, the study has also been approached as a whole, in order to obtain more solid results that can be extrapolated to the future knowledge and preservation of polychrome Iberian sculpture. This will allow for medium and long-term monitoring, implementing two protocols included in the MAN's Preventive Conservation Plan: monitoring and control of deterioration indicators; and monitoring and control of the level of soluble salts.

Three-phase study

Since its creation in February 2022, the working group has organised its work into three phases. The first consisted of compiling and studying the existing documentation on the sculptures, as well as drawing up joint work sheets. The second part dealt with the scientific-technical study, through the acquisition of images and analysis, to conclude with the establishment of a working methodology for monitoring conservation status. The third phase comprised the drafting and implementation of protocols for the monitoring and control of indicators.

During the process, a sequence has been followed in order to minimise the impact on the object, starting with global and specific studies without sampling. For this reason, the technical staff of the IPCE, with the necessary equipment, came to the museum to perform different imaging techniques: visible reference and detail photography and macro-photographs; visible fluorescence photography induced by ultraviolet radiation; luminescence photography in the infrared range induced by visible light; and thermography.

A working methodology was then designed to establish fixed points of analysis that would allow long-term monitoring of the degree of salinisation of each artefact. To this end, techniques such as high-resolution conductivity measurement, scanning electron microscopy and microanalysis using X-ray energy dispersive spectrometry were used. The main objectives of these analyses were to determine the nature of the organic materials and to assess whether the results obtained would help to establish the risk factors that could contribute to the deterioration of the work. In this way, the taking of micro-samples now makes it possible for archives to be kept at the IPCE, so that they can be consulted or studied again in the future without the need to take new samples from the same artefact. In October 2022, the data acquisition phase was completed and data processing, analysis and interpretation began.

Dama de Baza

For the study of the Dama de Baza, 11 representative points of deterioration and 14 sampling points of soluble salts were set, of which 6 points were selected for the salt monitoring and control protocol. According to the report, the analyses indicate ‘that variations in the hygrometric conditions in the environment of the Dama would trigger a complex process of dissolution and crystallisation of sulphate salts, which would compromise the unstable conservation status of the polychromy’.

Furthermore, the indicators show that 'any variation in environmental parameters resulting from a relocation of the construction site can trigger physical disturbance mechanisms'. He adds that 'the appearance of new cycles of dissolution and recrystallisation of salts would entail a risk of losses on the surface, both of stone material and of remains of polychromy'. Therefore, 'the disappearance of these strata would entail an irreparable loss for the knowledge of this exceptional cultural asset and of Iberian culture as a whole, mainly due to the fact that this piece preserves a large part of its original polychromy'. For this reason, the report determined that 'an external transfer would activate deterioration mechanisms with serious consequences' that 'would compromise the integrity of this work, which is so significant for Spanish Historical Heritage'.

Dama de Elche

In the case of the Dama de Elche, 17 representative points of deterioration and 20 sampling points of soluble salts were set, of which 6 points were selected for the salt monitoring and control protocol. The report states that the studies carried out 'confirm the vulnerable state of the sculpture's constituent material, taking into account the different types of deterioration that can be observed through the indicators'. The pathologies identified in the sculpture are the presence of salts, loss of polychromy and decorative appliqués, lack of cohesion with the stone support (flaking and disintegration), and products foreign to the constituent material.

The report states that 'all indicators show that any variation in environmental parameters resulting from a possible relocation of the artefact may trigger physical disturbance mechanisms'. According to the document, 'the appearance of new cycles of dissolution and recrystallisation of salts would entail a risk of losses on the surface, both of stone material and of remains of polychromy'.

The risk of loss or deterioration of the few surviving pigment remains, as well as traces of materials associated with the archaeological context, is estimated to be 'very high'. According to the report, 'the sculpture is currently in a very delicate state of equilibrium in relation to the environment in which it is preserved'. It holds that 'an external transfer would activate deterioration mechanisms with serious consequences', which would imply 'exposure to risks that would compromise the integrity of this work', a sculpture 'of extraordinary plastic quality, excellent workmanship and an exceptional iconographic model'. For this reason, as in the case of the Dama de Baza, it argues that 'guaranteeing its long-term preservation', we will be in a position to deepen our knowledge of the piece 'thanks to new techniques that will be developed in the future'.

Dama del Cerro de los Santos

For the Dama del Cerro de los Santos, 10 representative points of deterioration and 7 sampling points of soluble salts were set, from which 3 points were selected for the salt monitoring and control protocol. The studies carried out 'corroborate how, taking into account the different types of deterioration observed, the figure is practically morphologically complete and the limestone shows little hardness and fragility'. The report notes spot losses in the most prominent parts, such as corners, edges, hands and the plinth.

According to the report, of the three pieces under study, it is 'the one that is in a state of greater stability and lower salt content, which allows it to be exhibited to the public outside the display case'. It therefore recommends that 'it should remain in the same environmental conditions in which it is currently kept in order to guarantee its current state of equilibrium'.

Long-term protocols

The detailed analysis of the information obtained and the knowledge of these cultural assets makes it possible to establish effective and representative protocols for monitoring conservation status over time. The report explains that the results obtained through the methodology developed in the study phases of the ‘Ladies’ can be used as a tool to guarantee the quality of future conservation and restoration interventions on Iberian sculpture, which should have the long-term preservation of cultural assets as a top priority.