Rescat 34 English

34 EDITORIAL

Preserving public art Page 2

INTERVIEW

Salvador Butí Papiol Nati Salvadó Cabré Page 3

CONSERVATION-RESTORATION

Three Roman-era statues from the collection at the Museu Nacional Arqueològic de Tarragona Page 12

Conservation of the Santa Maria de Ripoll portal Page 16

Four polychrome Neoclassical reliefs of Can Boles (Amer, Selva) Page 42

NEWS

Nanorestart Final Conference in Denmark Page 46

A MUST-READ

The conservation of modern and contemporary paintings Basic Condition Reporting Page 47

CONSERVATION-RESTORATION

THE SANTA MARIA DE RIPOLL PORTAL

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Centre de Restauració de Béns Mobles de Catalunya

EDITORIAL

PRESERVING PUBLIC ART Public sculpture has been part of the urban landscape since antiquity. The streets of ancient Rome were like an outdoor museum; in fact, the Romans were the first to implement official measures to protect art. In the fourth century, under Constantine the Great, a curator statuarum was named to maintain the statues located on public streets.

Since then, all over the world, public art has consistently undergone processes of pillage, destruction and neglect. Over the course of the nineteenth century, states became increasingly aware of the importance of preserving their heritage. However, in the case of public sculpture and public art in general, it was not until the second third of the twentieth century that councils and the other institutions that owned this heritage began to take steps towards creating inventories and catalogues.

Even so, these documents do not usually include information on the artefact’s conservation, let alone any conservation plans written up by qualified conservator-restorers that set out the preventive conservation and restoration activities it requires.

It is still common to see public sculpture conservation activities being carried out by the municipal maintenance department, supervised—with a bit of luck—by municipal architects or—even better—by the conservator-restorer from the local museum, if there is one. This translates as the repeated use of cleaning and restoration methods that are incompatible with the artefact’s long-term conservation.

To remedy this situation, here at the Centre for the Restoration of Artefacts of Catalonia (CRBMC), we are working on a pilot project through which we can use certain criteria and protocols to define a model that can be used by all the institutions that own public art in Catalonia.

It is important for public art to be included in legally protected catalogues and for any preventive conservation and other activities carried out on public art to be at least as prudent and effective as those performed on other artefacts that make up the cultural heritage of Catalonia. Àngels Solé, director of CRBMC

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CRBMC technician examining the Diàleg set of sculptures,

by Pep Codó (1993), made from basalt from Castellfollit.

They are two large heads that aim to symbolise the dialogue encouraged by the Sant Cugat del Vallès Cultural Centre.

Their dimensions are: 2,50 × 2 × 1,5 m and 3 × 2,70 × 0,90 m.

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INTERVIEW

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Ricardo Suárez, chemist at the CRBMC

SALVADOR BUTÍ PAPIOL / NATI SALVADÓ CABRÉ Scientists from the Analysis of Cultural Heritage Materials Research Group (AMPC) of the UPC. Polytechnic University of Catalonia.

SCIENTIFIC TOOLS FOR DEEPENING KNOWLEDGE OF ART WORKS THE LINK BETWEEN THESE TWO SCIENTISTS WITH A PASSION FOR ART AND THE CENTRE FOR THE RESTORATION OF ARTEFACTS OF CATALONIA (CRBMC) GOES WAY BACK TO WHEN ITS OFFICES WERE STILL LOCATED IN THE MONASTERY OF SANT CUGAT DEL VALLÈS Salvador Butí Papiol Graduated in 1976 with a degree in Chemistry from the University of Barcelona and a PhD in Chemistry from the same university in 1998. Trained as an analytical chemist, he has worked on the study of equilibria in non-aqueous and hydro-organic media. In the last few years his research has focused on Cultural Heritage materials. He is currently a professor in the Department of Chemical Engineering of the UPC. Polytechnic University of Catalonia, at the Polytechnic College of Engineering of Vilanova i la Geltrú.

Nati Salvadó Cabré Graduated in 1990 with a degree in Chemistry from the University of Barcelona and a PhD in Chemistry from the same university in 2001.

Her doctoral thesis was on the characterization of materials in the paintings of Jaume Huguet. Her research has always focused on cultural heritage, especially in the field of painting. She is currently is an associate professor in the Department of Chemical Engineering of the UPC. Polytechnic University of Catalonia, at the Polytechnic College of Engineering of Vilanova i la Geltrú.

The first significant contact between Nati and Salvador with the Centre began during the time the restorer Joaquim Pradell i Ventura (Badalona, Barcelonès, 1921 – Barcelona, Barcelonès, 27 June 2011) was there working on the restoration of the retaule del Conestable (retable of the Constable), by Jaume Huguet.

Later on, as well as teaching the odd course and the odd lecture, in 2006 while working in their Analysis of Cultural Heritage Materials Research Group (AMPC) at the Polytechnic University of Catalonia (UPC), they drafted the document Proposta de creació d’un laboratori d’anàlisi de suport a la restauració (Proposal for the creation of an analysis laboratory to provide support to restoration works), which had been commissioned by the Ministry of

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Culture and Communications Media of the Government of Catalonia.

This Analysis of Cultural Heritage Materials Research Group (AMPC) focuses on the study of materials with historical, archaeological, artistic and cultural heritage interest, through chemical analysis techniques and the use of large scientific facilities. Based on knowledge of the composition of a material, the chemical mechanisms behind ageing and alteration processes can be explained, which is of primary concern in the field of conservation and restoration.

Since that first proposal document, as well collaborating with advisory work at the CRBMC’s laboratory, they have participated in the analytical study of certain pieces

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I’ve always carried out research on issues related to chemistry (material analysis) applied to cultural heritage.

I started my dissertation at the University of Barcelona (UB) on a painting from the Saint Francis series by Antoni Viladomat, which is preserved in the National Art Museum of Catalonia (MNAC).

Salvador. My beginnings as a researcher had nothing to do with heritage analysis. For years I dedicated my time to assigning pH values to standard reference solutions with non-aqueous media. At a certain point, I noticed that the subjects that Nati worked on, who I’d already known for a long time, were much more interesting, considering I had always been interested in history and art. This led to a radical change in my research work. We decided to create our own research group at the UPC, together with Trinitat Pradell. Looking back now, it was an excellent decision.

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During an experiment in England, in 2001. From left to right, Emmanuel Pantos (scientist at the Daresbury Laboratory, Synchrotron Radiation Source, England), Nati Salvadó and Trinitat Pradell. Photo: Archive of the Analysis of Cultural Heritage Materials Research Group (AMPC).

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(mostly on specific projects), including the majestat de Beget; the 15th-century retaule de la Flagel·lació, by Martín Bernat, from the former Gòdia Foundation, also directed by the daughter of Joaquim Pradell, Trinitat Pradell; and the Creu de Sant Joan, from the church of Sant Joan de les Abadesses.

In addition, together with the CRBMC’s chemist at that time, Núria Oriols, they were involved in the book Presa de mostres de policromies (Polychrome sampling), as part of the Museums-Documentation collection, published by the Ministry of Culture and Communications Media of the Government of Catalonia in 2008.

What motivated you to study cultural heritage materials?

Nati. My interest in art goes way back. I’ve always liked manual work, creative work... and I’ve always also been very interested in art, especially painting. The relationship between science and art I believe has allowed me to get a better understanding of art. It’s a different way of approaching art works. And once you have more information about the materials, how they are structured, how they interact, you take another look at the work more objectively, you understand it and value it more. In fact,

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What was it like at the beginning?

Nati. When I first started working here, there was practically no one devoted to paintings. At the Art Museum of Catalonia (now known as the MNAC) there was the chemist Antoni Morer, who helped me to study the works of Viladomat. And that’s how I started developing the methodologies of study, both for choosing and applying analysis techniques and for preparing and handling the samples, while at the Department of Inorganic Chemistry of the University of Barcelona and with the help of Professor Miquel Seco.

At that time, bibliographic searches were more difficult; now it’s much easier to access international publica-

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DURING MY THESIS WORK, I WAS VERY AWARE OF THE NEED FOR INTERDISCIPLINARY COLLABORATION, BOTH IN SCIENCES AND IN RESTORATION AND ART HISTORY Nati Salvadó Cabré

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tions and there are also a lot more of them. Later on, when I started my doctoral thesis, I contacted Marius Vendrell, who managed a team at the Geology Faculty of the UB and who already had experience in heritage matters. Màrius became co-director of my thesis, together with Miquel Seco from the Faculty of Chemistry. While working on my thesis I was very aware of the need for interdisciplinary collaboration, both in the field of science and in the field of restoration and history of art. For example, I remember the chats I had with the restorer Joaquim Pradell and the help he gave me very well. Later on, at the UPC where I was a professor, we set up the Analysis of Cultural

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Salvador Butí at the infrared spectroscopy line at the Daresbury Laboratory, Synchrotron Radiation Source, in 2004. Photo: Archive of the AMPC (UPC)

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Heritage Materials Research Group. Since my thesis had focused on the study of Jaume Huguet's work, in the early days of the group we focused our research on retables from the Gothic era.

Was it easy to form a research group in this area at your university?

Salvador. We had to do a lot of convincing. It’s a topic that seemed to them very unrelated to those more commonly associated with engineering. In practice however, we end up performing materials analysis and applying common techniques. We set up the research group practically from scratch, and although that sounds like it might have been a problem, it was really an exciting challenge. We’ve gradually managed to build our own laboratory, we’ve worked collaboratively with others, etc. As an example, we have always been in contact with the CRBMC and the MNAC, since our research focuses on paintings and polychrome works, and collaborated more sporadically or with more or less continuity with museums such as the Maritime Museum of Barcelona, with the School of Art and Design of Tortosa, with different restoration groups and, more recently, with the Barcelona City History Museum (MUHBA).

In terms of using instrumental techniques at our university, in addition to the equipment we have in our own laboratory, at the Polytechnic College of Engineering of Vilanova i la Geltrú (EPSEVG), and the equipment that Trinitat has at the Campus Diagonal–Besòs / Barcelona East School of Engineering (EEE), which we have acquired over time on the basis of competitive projects, we have also

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Conference given by Salvador Butí and Nati Salvadó: "Il·luminar per conèixer: un viatge a l’interior de les pintures” (Enlighten to understand: a journey inside paintings), during Science Week, as part of the International Year of Light and Light-based Technologies 2015 Polytechnic College of Engineering of Vilanova i la Geltrú (EPSEVG) at the UPC. Photo: Promotion services.

EPSEVG (UPC)

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Nati Salvadó at the BM16 X-ray diffraction line at the European Synchrotron Radiation Facility (ESRF), in Grenoble, in 2009. Photo: Archive of the AMPC (UPC)

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established a partnership with the Centre for Research in Science and Multiscale Engineering of Barcelona which is well equipped with scientific apparatus. Therefore, we currently have access to a wide variety of analysis techniques and some particularly good equipment.

Nati. Both of us focus on studying paintings and polychrome works, but Trinitat works more with ceramics and glass artefacts in collaboration with geologist Judit Molera from the University of Vic (Uvic). They make a good team with complementing areas of expertise.

What is your contribution to art and art history?

Salvador. Our work provides another approach to appreciating works of art, because by knowing how they are created and what techniques and materials are used you can better understand them, evaluate them in their historical context and see how they have evolved over time.

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OUR GOAL IS TO COMMUNICATE THAT OBJECTS ARE CONSTANTLY EVOLVING, THAT THEY ARE NOT JUST THE PRODUCT OF A COMBINATION OF SUBSTANCES, THAT THEY ARE REACTIVE Salvador Butí Papiol

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Nati. It is important to be conscious of what you have in your hands, often unique pieces of significant historical and artistic value. With the passing of time, you acquire a deep knowledge of the technical traditions and the materials used in the creation of art works.

We provide information on what materials are used in the works, how they are distributed, what impurities are associated with them... All this helps us to understand and interpret the origin of the materials and the technology used. Sometimes we find substances that are not part of the original, but have appeared over time due to chemical reactions either between the materials themselves or with the environment. Sometimes the materials are from previous restoration processes. All this contributes to the appearance or perception of the work as it appears today.

How does your work fit in with conservation and knowledge of art?

Salvador. It’s about finding a language which we can all understand. This means that each member of the team has to know how to ask the right questions, so that they can be correctly interpreted, and the same with the answers. This means you need to be prepared to ignore the jargon used in each area and respect and value the work done by each member. We want to convey the fact that material objects are constantly evolving, that they are not simply the result of a mixture of substances, but that they are reactive. Understanding the reactivity that exists in a painting is obviously helpful when it comes to preserving it or managing a restoration process.

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Nati. It’s a team effort, between chemists, physicists, geologists, etc. and restorers and conservators; its becoming more and more clear that we all have to work together, and everyone knows where their limits are. Together we are doing some very interesting things.

This sometimes leads, for example, to questioning whether certain analyses are necessary. You need to really know what data you’re going to obtain before conducting a study. Not everything has to be analysed, nor should every technique be applied.

What work do you do in this area at the university?

Nati. Our work has to mainly be research, establishing new methodologies for analysis, achieving good results with the minimum amount of samples or intervention on the pieces, and even introducing new techniques for analysis and improving procedures. Trying to understand the chemical reactivity that has occurred in the pictorial layers. This research enables us to discover simple methods that can then be applied more generally. Obviously, this contribution can be applied to other scientific fields.

Salvador. At the university we’re able to work on long-term projects, while the laboratories of restoration centres and museums have to respond more to immediate needs. Our idea is to provide all the museums and restoration groups with access to laboratories where the most basic analyses can be carried out, in order to respond to the most common and immediate needs.

As university members, we also have a teaching role, which in this case means explaining the chemical concepts involved so that they are followed correctly and rigorously, and at the same time are practical, useful and understandable. For example, there are concepts, such as the pH scale, which are widely used by restorers in cleaning methods, but which are complex and not always interpreted properly.

It’s also part of our job to train researchers, mainly through doctoral programs and training courses. In this regard, we directed the doctoral thesis on the ageing of resins, by Victoria Beltran, who worked for a while in the CRBMC laboratory.

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The restorer Teresa Sala, from the Maritime Museum of Barcelona, and Nati Salvadó in the process of taking polychrome samples from an ex-voto model boat, in 2015. Photo: Archive of the AMPC (UPC)

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Salvador Butí and Nati Salvadó in the process of taking samples at the Maritime Museum of Barcelona, in 2017. Photo: M. T. Sala. Maritime Museum of Barcelona

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Nati. And we’re currently directing the doctoral thesis of Núria Orioles, a chemist at the MNAC, on Romanesque wall paintings. We’re amazed that there are still so many things to learn about techniques and materials. And it is proving to be a very interesting study.

Tell us about one of your research topics that you find particularly interesting...

Salvador. All of them have been quite interesting, but if I had to pick one it would be the study of reaction compounds, and especially carboxylates, both soaps and resins; it’s one of the subjects we have spent the most time researching. We have been quite pioneering in the study of

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From left to right, Trinitat Pradell, Nati Salvadó, Herman Emerich (scientist at the BM01 line at the ESRF Synchrotron), and Salvador Butí, during an experiment at ESRF Grenoble, in 2009. Photo: Archive of the AMPC (UPC)

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the reactivity in egg tempera paintings, mostly focusing on gothic panel painting. By the way, they’re about to publish a book on metal soaps in art, for which we have written a chapter, which came about after a series of seminars that brought together international specialists at the Rijksmuseum in Amsterdam.

Nati. Another interesting topic which we have worked a great deal on is in the alteration of silver leaf (less than a micrometre thick!). Also on its resin coating, what we call “corladura”. We have actually been working on this subject, jointly with the restorer Carme Clemente, from the School of Art and Design of Tortosa, in regard to the set of retables of the cathedral of Tortosa, which was her doctoral thesis, and which I codirected. I think it’s a good example of a very productive interdisciplinary collaboration.

What is your work methodology?

Salvador. It depends on whether we’re talking about solving a conservation issue, or contextualizing a work of art historically, or improving an analytical technique...

Nati. For example, in order to study the alteration of a particular piece, we first try to obtain as much information as possible, including its history and its location. With this, we usually (not always!) draw up a plan for taking samples; this is always the key part, since it must be sufficiently representative but as non-invasive as possible. It’s at this stage that the collaboration and help of conservatorsrestorers is key. We then start with the strategies for analysing the samples. We always start by looking at the

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TO STUDY AN ALTERATION PROBLEM ON A SPECIFIC PIECE, INITIALLY, WE TRY TO UNCOVER AS MUCH INFORMATION AS POSSIBLE ABOUT IT, WHICH INCLUDES ITS HISTORY AND LOCATION Nati Salvadó Cabré

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samples under an optical microscope, a preliminary step to decide which analysis techniques are most suitable and to prepare them appropriately. From the data obtained from the analyses we come up with a solution which has to work for the whole piece. With the explanation of the data obtained, and having commented and evaluated this with the conservators-restorers, we can determine the most appropriate conservation methods.

Salvador. It’s worth pointing out that quite often a particular study can open up a new, broader, research opportunity. The alteration of a specific material may lead to a more systematic and wider study. It’s difficult to define a specific methodology because we don’t always follow routine analyses, since each case is very different. Sometimes, we are more interested in identifying the materials, let’s say pigments for example; on other occasions, what really interests us is to understand what reaction has occurred between the pigments and the binding medium: for

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Trinitat Pradell and Nati Salvadó during the preparation of samples, in 2017. Photo: Archive of the AMPC (UPC)

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From left to right, Victoria Beltran, Nati Salvadó, Salvador Butí and Trinitat Pradell during an experiment at the Diamond synchrotron, in England, in 2014. Photo: Archive of the AMPC (UPC)

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example, how soaps are produced if the medium contains fatty acids. But the presence of a resin that can also react with the pigment might come into play and the problem can become more complex.

Given that in general the paint samples are very small, with overlapping heterogeneous layers up to a few thousandths of a millimetre thick, we need techniques that allow us to go into a great deal of detail, such as those associated with microscopy. The techniques we use most are optical microscopy, electronic microscopy, infrared and Raman spectroscopies and X-ray diffraction.

And do you use any non-invasive techniques?

Salvador. To begin with, it’s difficult to define what we mean by a non-invasive technique, a non-destructive technique. Each technique allows you to obtain information, sometimes limited; that's why usually several techniques, which provide complementary information, must be applied. There are some that can be used directly, in situ, on the piece; the scope of the information that can be obtained is different from that obtained from a microsample. We need to know what information is required to solve the problem. Taking the right sample can be much less invasive than a direct analysis of the piece. It depends, it needs to be assessed in each case.

A good strategy for sample analysis, which takes into account the possibility of applying several complementary techniques, can provide a great deal of information. This means applying some techniques that do not destroy the sample. Also, it’s worth remembering that any measure requires some sort of interaction with the material, to a greater or lesser degree.

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And why do you use instrumental techniques that use synchrotron light?

Nati. We started looking for solutions using synchrotron light due to the complexity of some of the issues we faced.

And I’d like to point out here that the help of Manolis Pantos, who was a scientist at the Synchrotron Daresbury, England, was key. He is now retired, but he is an extremely enthusiastic person and he encouraged us and helped us a great deal in our work. He really helped to promote and arrange meetings between users of synchrotron light-associated techniques applied to the study of cultural heritage.

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Nati Salvadó while taking of samples from a retable, at the CRBMC facilities. Photo: Lourdes Domedel

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A synchrotron is a particular type of particle accelerator using particles such as electrons. When the electrons rotate at high speed, in a circular orbit, they emit light of many types in the direction of their movement; that is, at a tangent to the orbit of the electrons. The so-called synchrotron light that is emitted is used in what are called light lines, to which the instrumental techniques are connected.

Synchrotron light requires large facilities which are expensive. Therefore, any analyses have to be carefully planned, justified and must be impossible to carry out with other conventional techniques. Due to the very bright and very collimated characteristics of the light synchrotron, we can obtain more information and of a higher quality from the microsamples than through the use of conventional light sources, such as X-ray diffraction or infrared spectroscopy. We mainly use it for very specific research topics. Access to a synchrotron is restricted and must be requested many months in advance. It only makes sense for medium and long-term research projects.

What are the main problems you encounter?

Nati. Fortunately, in our country we have a lot of heritage artefacts, but on the downside, there are only a few of us who specifically dedicate ourselves to this field. It must be said that it requires a great deal of specialization. There is a lack of resources for training specialists and PhD students, and this makes it hard to set up work teams.

It should be noted that while our specific work is clearly scientific, it also shares a lot of aspects with humanities and so isn’t a part of any priority strategic plan.

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FROM A PURELY TECHNICAL VIEWPOINT, ONE OF THE MOST SIGNIFICANT HANDICAPS TENDS TO BE A LACK OF REFERENCES AMONG AGED MATERIALS. THE PASSING OF TIME CANNOT BE SIMULATED OR IMPROVISED Salvador Butí Papiol

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Salvador. From a purely technical point of view, one of the most important hindrances are the lack of references for aged materials. The passage of time cannot be simulated or improvised. And not all restorations and interventions have been well documented. The effects of the use of some restoration materials can’t be assessed until enough time has passed, and sometimes this requires a great deal of time. There isn’t always enough information available.

How do you publicize your research?

Salvador. In different circles. On the one hand, through conferences, courses and publications of a more local and informational nature and on the other, at an international level, we publish the most scientific and innovative aspects of our research in journals specializing in chemistry, physics and materials. We also participate regularly in international conferences. This is how our work is valued and this allows us to compete with other groups of scien-

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Salvador Butí, Nati Salvadó and Carme Clemente at the CRBMC facilities. Photo: Lourdes Domedel

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tists for access to resources. It also provides us with the possibility of participating in competitive projects to use large-scale equipment such as the synchrotron.

Are there many research groups like yours?

Nati. Not many. We are few and far between and usually under resourced, especially in terms of personnel. However, thanks to collaboration with other research groups (not necessarily in the same field) and multidisciplinary projects, there are networks for sharing equipment and experiences. In Europe, there is the IPERION CH consortium which promotes the exchange of research and cooperation in this field. It is comprised of research institutes and laboratories, conservation centres, museums and universities.

Internationally, there are some groups and some museum laboratories with good infrastructures and resources, but there are also many works in this field that are not published, which sometimes makes it difficult to really assess what is being done. A lot of specific studies have been carried out without context, in which the art work is simply an excuse for the study, and they end up serving very little purpose. We believe this is a misguided

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approach. But, fortunately, this has changed, and little by little there are more specialized conferences and research groups that are dedicated exclusively or almost exclusively to these sorts of topics. There are now even conferences and seminars on very specific subjects, with a high scientific level. There are also very interesting and high level publications.

What do you think about restoration work that is carried out without a previous analytical study?

Salvador. Permanent damage can be done unintentionally. As we have said, analyses are not always necessary, but the issue must be thoroughly investigated. Ideally, all restoration teams should have access to a reference laboratory that is well-equipped with staff and apparatus. Today, with the information we have, not carrying out an assessment based on knowledge of the materials is inexcusable.

Nati. You have to find the way to facilitate things, to ensure there are laboratories and teams of trained professionals that can respond to these needs, as and when required depending on how the restoration work progresses. Public institutions need to make an effort in this regard.

Studies in the field of restoration, and those focusing on art history, also have an important role to play in publicizing the importance of science and scientific knowledge in art works. Technological progress and artistic creation often go hand in hand. And in the same way, the conservation of a piece goes hand in hand with the knowledge and behaviour of the materials used in it.

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CONSERVATION–RESTORATION

ARQUEOLOGY

Three Roman-era statues from the collection at the National Archaeological Museum of Tarragona

THE MNAT IS CURRENTLY BEING REFURBISHED AND RENOVATED which has led to the transfer of virtually every collection that was on public display.

Introduction While this refurbishment lasts, most of the objects are being displayed temporarily in a space in the Port of Tarragona, including the set of statues in question.

These sculptures were part of the decoration of the scaenae frons of the Tarraco theatre, built in the time of Augustus. The pieces were found in that location during the archaeological excavations that took place in the early 20th century.

In order to restore them in a space with the appropriate equipment, the pieces were transferred to the CRBMC wall painting and stone sculpture laboratory, where the necessary conservation and restoration treatments have been performed in order to improve their state of conservation and readability.

Description The figures represent members of the imperial family, two of them dressed in togas and the other wearing military attire. The larger than life-sized statues were carved in Carrara marble and polychromed.

State of conservation The sculptures have lost parts that had originally been carved from separate blocks, such as the heads, arms and hands. Where these joined with the limbs, some of the iron rods used to support the connections have been preserved, though they are showing signs of rust.

It is worth noting that the main structures have suffered material losses, cracks and fractures. We have found drip stains from synthetic resins used

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The cuirassed statue on display at the National Archaeological Museum of Tarragona (MNAT). Photo: Pau Arroyo

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One of the cuirassed statue’s feet before the intervention. A grimy layer can be seen. Photo: Pau Arroyo

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Pau Arroyo Casals, conservator-restorer of cultural assets (Lesena, Servei Integral al Patrimoni, SLU).

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Mapping of the damage, polychrome and foreign materials on the cuirassed statue. Orthophotograph: Jaime Salguero Drawing: Francisco Justicia

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Remains of red pigment Remains of blue pigment Volumetric reintegration Remains of adhesive

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Rust stain Bolt Fracture Remains of paint Colour alteration Scratch marks

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Macrophotograph of the remains of blue pigment found on the cuirassed statue using a digital microscope at 50x. Photo: Ares Pérez

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The cuirassed statue after the conservationrestoration process, and once installed in the temporary exhibition at Tinglado 4 of the Moll de Costa in the Port de Tarragona.

Photo: Pau Arroyo

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Close-up from above of the joining mechanism of the cuirassed statue showing the screw assembly. Photo: Pau Arroyo

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Close-up from below of the cuirassed statue’s support system, which bears the 550 kg of this part of the sculpture.

Photo: Pau Arroyo

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Cleaning the marble surface of the togaed statue (inv.

45601 / CRBMC 13388) with a chelator-based solution. Photo: Pau Arroyo

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The togaed (inv.

45601 / CRBMC 13388) after the conservationrestoration process at Tinglado 4 of the Moll de Costa in the Port de Tarragona.

Photo: Pau Arroyo

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Upright positioning of the togaed statue (inv.

Number 45601 / CRBMC 13388) using the bridge crane in laboratory 1 of the CRBMC. Photo: Adrià Arroyo

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The central part of the togaed statue (inv. umber 7584 / CRBMC 13386) during the cleaning process. Photo: Pau Arroyo

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to join fragments, reintegration plaster work and on the surface there are widespread dirt deposits.

The state of conservation of the polychrome remains varies from statue to statue, although most of it has been lost, especially in one of the togaed figures and the one with the cuirass.

As for the material losses, it is worth noting that one of the togaed figures and the one with a cuirass are missing part of their lower limbs, so they require supports to be exhibited upright.

The conservation-restoration process The process has involved applying various treatments to the sculptures. A general cleaning of the surfaces of the works has been carried out, first dry and then with a solution prepared with chelators. Depending on the case, the product has been applied either using cotton swabs or using sheets of kitchen roll.

It was also necessary to remove the elements of plaster reintegration and remains of glue (mostly in the form of a drip stains) used in an previous intervention to join the fragments of the cuirassed statue.

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Photo of the togaed statue (inv. 7584 / CRBMC 13386) at the National Archaeological Museum of Tarragona, before its transfer to the CRBMC for restoration. Photo: Ramon Maroto (CRBMC

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Scanning the bottom of the togaed statue (inv. 7584 / CRBMC 13386), in order to manufacture a support element using a numerical milling machine. Photo: Pau Arroyo

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Virtual image of the positioning of the support adapted to the shape of the fracture zone, required to ensure the stability of the statue (inv. number 7584 / CRBMC 13386).

Photo/virtual image: Francesc Montero

DETAILS

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The manufactured and installed support, during the assembly process of the sculpture at the exhibition in the T4 of the Port. Photo: Pau Arroyo

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The elements of plaster reintegration on one of the togaed statues have also been eliminated.

These operations have been done mechanically and, in the case of the glue, a solvent was first applied using a poultice, in order to soften it.

The existing polychrome on the toga of one of the pieces has been cleaned with a rubber eraser and a vulcanized smoke sponge. In some parts, the polychrome has been consolidated with an acrylic resin solution.

The metallic elements have been cleaned mechanically and an inhibitor and a layer of acrylic resin has been subsequently applied to the surface. Several stone fragments have also been stuck back together using synthetic resins.

Some gaps cracks and joints of the fractured parts have required reintegration. In this case, a mortar made of marble powder and a synthetic binder has been used.

Support systems It was necessary to design and build support elements adapted to the characteristics of two of the pieces, in order to keep them upright.

In the case of the cuirassed sculpture, a metal structure has been built that holds it up without the need for any bolts. Regarding the togaed statue, an element with high resistance resin has been developed based on a 3D model, machined with a numerical milling machine.

GENERIC CLASSIFICATION: sculpture | OBJECT: 3 statues | MATERIAL/TECHNIQUE: carved marble with remains of polychrome | DESCRIPTION: 2 figures with togas and one with a cuirass | DATE/PERIOD: 1st century | DIMENSIONS: CRBMC 13386 / Inv. MNAT 07584: Togaed. Possibly Augustus. 283 × 85 × 52 cm I CRBMC 13387 / Inv. 45602: Cuirassed 200 × 94 × 47 cm I CRBMC 13388 / 45601: Togaed. Possibly Claudius. 200 × 76 × 40 cm | LOCATION: (MNAT) National Archaeological Museum of Tarragona, (Tarragonès) | ORIGIN: Roman theatre, Tarragona (Tarragonès) | CRBMC REGISTER NO.: 13386 (togaed, possibly Augustus), 13387 (cuirassed) and 13388 (togaed, possibly Claudius) | INVENTORY NO.: respectively, 07584, 45602, 45601 | COORDINATION: Pere Rovira | RESTORATION: Adrià Arroyo, Pau Arroyo, Francisco Justícia and Ares Pérez | YEAR OF RESTORATION: 2018

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CONSERVATION–RESTORATION

POLYCHROME SCULPTURE

Conservation of the Santa Maria de Ripoll portal THE RIPOLL PORTAL IS KNOWN AS THE STONE BIBLE thanks to its extraordinarily complex iconography.

INTRODUCTION

This monument can be read like an illustrated, propagandistic book. Its bas-relief pieces recount passages from the New Testament and, especially, the Old Testament, with iconographic references from the Ripoll Bible (BARRAL 1973), held at the Vatican Apostolic Library, and the Roda Bible, kept at the French National Library and also made in Ripoll.

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Architecturally, it is the monastery church’s entrance portal and was embellished to match the building’s sumptuous finish and enhance the main façade, recalling the style of Roman triumphal arches.

To assess its state of conservation, after identifying the materials with which it was made, we must discover its history and the events that have accompanied it and, above all, altered its sculptural surface.

The date the portal was built and who created it are still much debated today. The construction is thought to date from between 1140 and 1160 and

Patrícia Amat and Rudi Ranesi, conservator-restorers of cultural artefacts Pere Rovira, conservator-restorer, coordinator of the Mural and Stone Sculpture Department at the CRBMC M. José Gracia, conservator-restorer, specialist in preventive conservation at the CRBMC

to be the work of an artists’ workshop (known as the Ripoll Workshop) with links to the workshop of Gilabertus of Toulouse (GOLDSCHMIDT 1939).

According to art historians, this influence is especially evident in the Saint Peter and Saint Paul figures, derived from the column figures on Toulouse’s Saint-Etienne Cathedral (CAMPS 2009) and early twelfth-century Lombardy sculpture (CAMPS 2014).

The triumphal arch-style construction and the widespread use of images make this a unique monument in Catalonia, as the other two simi-

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General view of the portal, before restoration. Photo: Josep Giribet.

Calidos®, 2012. Catalan Cultural Heritage Agency Link to Calidos website. The photo is displayed as a gigapixel image, so that the user can zoom in on the details: http://www.calidos.cat/portfolio/ portic-de-santa-maria-de-ripoll/

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General view of the portal, after restoration.

Photo: CRBMC, 2017

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lar pieces, the portal on the Sant Pere de Rodes Monastery and the façade on Vic Cathedral, have disappeared (LORÉS 2007).

No other similar monument in Catalonia or Spain is as well preserved as this one, as it is being treated as a museum artefact, within a controlled space and environment. Within this context, a series of restoration activities have been carried out.

TECHNICAL ANALYSIS. COMPOSITION

The Ripoll portal is a large polychrome stone sculpture. In terms of shape, it is a rectangular parallelepiped composed of cut stone blocks with bas-relief decoration put together in a stretcher bond formation in rows of ashlars (seven horizontal registers) to form a wall attached to the church’s main wall, filled in with stone and lime mortar.

In fact, this stone portal replaced the church’s original door, which dated from around 1032 (LORÉS 2007) and presented a fresco painting finish, as we can see on the preserved remains of the upper part (BARRAL 1973).

The Roman arch-style structure means that the piece stands up vertically on its own. As it is not built in to the church’s main walls, it is not af-

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The west façade of Santa Maria d’Agramunt Church, after restoration of the portal and rose window.

Photo: Catalunya Medieval. Ricard Ballo, 2017

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Illustration by J.C. Langlois that depicts the structure of the portico in the early nineteenth century (between 1811 and 1826) It was published in the book: Voyage pittoresque et militaire en Espagne. Catalogne, by J.C. Langlois (Colonel Jean-Charles) 1789–1870.

Paris, Engelmann & Cie., 1978 (reproduction of the 1830 book) Original caption: “Vue du couvent de San Benetto a Ripoll”

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Drawing by J. Berga i Boix, 1867. Photo: The Plana Berga family’s photography collection. El Ripollès Regional Archive

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fected by the building’s movements; this makes it stable independently. This stability has contributed towards the monument’s preservation through earthquakes and collapses suffered by the rest of the monastery.

Technically speaking, the portal is made up of around four hundred and fifty pieces of sedimentary stone of differing dimensions, with an average thickness of 45 cm. The piece is 7.14 m tall and 11.54 m wide, with a depth of 1.02 m on the outside and 1.93 m in the entrance opening, which gives the entrance an added volume of 90 m3. For its construction, 30 m3 of sedimentary stone was used, which created a visible sculpted surface of 80 m2 and a weight of 70 tonnes, approximately.

The stone used for the portal is a relatively uniform sandstone from the Bellmunt Formation (Eocene) near the monastery, although there is no documentary record of the old quarries. The pieces present varying components and textures, with clay fragments, a presence of quartz, mica and calcite, and different clast sizes. These characteristics lead us to classify the pieces into three types of stone (VENDRELL 2004):

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• Red homometric sandstone (fine grain with clay strips) • Grey calcarenitic sandstone (coarse grain) • Red heterometric sandstone (medium grain) HISTORY. STATE OF CONSERVATION AND CAUSES OF DETERIORATION

The monument presented a low degree of diagenesis (little sediment compaction), with occasional transformations of calcite into dolomite, which led to a reduction in grain volume, the resulting broadening of its intergranular porosity and a loss of mechanical properties and, simultaneously, contributed to biological colonisation.

Over the years, the materials’ ageing process and the surrounding human environment contributed to the erosion and loss of the polychrome layer, which led to the stone being exposed and entering an irreversible process of deterioration; as well as its decorative function, polychrome acts as a protective layer on cut stone.

The construction of an atrium or portico in front of the portal, between 1280 and 1310, was a key factor in the piece’s conservation. The ad-

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dition of an outer construction (which still stands today) to protect the portal, just a century after it was built, has led to the conservation of the monument’s constituent materials. If there had been no atrium, it would be impossible to create the ideal conservation space, like this one, which is based on the architectural space around it. It is likely that, without this construction, the Ripoll portal would not be here today.

It is clear that the deterioration of the portal’s stone was predetermined by the weakness of the sedimentary rock used, by the portal’s location in an outdoor environment with an extreme, humid climate, by the proximity of an irrigation canal and by industrial pollution. Another major contributing factor to the portal’s deterioration is the anthropic alterations that have caused mutilations to the sculpture, deriving from social incidents throughout the history of Catalonia from the seventeenth century onwards. Above all, its deterioration was caused by the years in which the monastery was abandoned, from 1835 (the year of the pillage and fire) to 1861, after which the first efforts to preserve the ruins were undertaken, led by the Girona Monuments Commission and the Barcelona Academy of Fine Arts. Although these activities were halted in 1868 for financial reasons, it is important to note that the atrium roof was repaired during this time.

The portal was not protected by the atrium roof for around twenty-five years, from 1840 to 1865 (LLAGOSTERA 2012), although images suggest that a provisional roof was put into place at the end of this period to protect the monument temporarily. During this time, the portal gradually lost its polychrome layer, which acted as a protective barrier. As the stone came into direct contact with the outside environment, it began to deteriorate and its state of conservation declined.

When the State transferred ownership of the monastery back to the Bishopric of Vic in 1885, Bishop Morgades set about promoting the reconstruction and recovery of the monastery, which would be carried out by architect Elias Rogent and finished in 1893. Although the building was in ruins, a full restoration of the monastery’s architecture was undertaken, with a view to maintaining Catalan historical memory and turning the site back into a place of worship. The portal and the two wings of the cloister still stood in their place, with no modifications, as they had not subsided.

On the portal, some lost fragments were reintegrated and the atrium roof was rebuilt.

Throughout the twentieth century, the monastery site continued its activity as just a parish church, of which the portal was the main entrance. Alterations to the portal intensified in the early twentieth century, especially from 1930

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The monastery in ruins around 1877, before the restoration by Elies Rogent (photograph by Marc Sala, to illustrate the book Santa Maria de Ripoll, by Josep M. Pellicer).

The photo comes from the first series of 12 images in the album created by photographer Marc Sala in 1878 (a second edition, with 18 photos, appeared in January 1880) and sold with Josep M. Pellicer’s book, Santa Maria de Ripoll, Girona, 1878

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onwards. The construction of factories next to the monastery, a population boom and the city’s urban remodelling were all factors in the portal’s deterioration.

The portal’s importance for the administration became clear in the Spanish Civil War, during which much effort was made to preserve it. However, it is important to note the damage caused by the numerous unfortunate restoration attempts made in the second half of the twentieth century all over the portal. Experimental conservation methods were being used all over Europe.

Until the first serious scientific and architectural studies in the 1960s, led by Alejandro Ferrant (architect for the fourth area of the National Artistic Heritage Defence Department, which covered Catalonia, the Valencian Community and Mallorca), both the portal’s state of conservation and the chances of stopping its deterioration were unknown.

Studies suggested that the cause of the damage to the stone, which was weak anyway, was moisture generated by various factors: the circulation of air between the portal and the cloister, blocked rain gutters and drains, the pavement

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Reconstruction of the portico roof (between 1886 and 1893). Photo: El Ripollès Regional Archive

Photograph of the square and the monastery before 1944. View of the façade of the Santa Maria de Ripoll Monastery, before 1944.

Photo: Valentí Fargnoli. INSPAI, Centre for Images. Girona Provincial Council

around the portal (below the level of the rest of the square), and the portal’s exposure to adverse weather and, therefore, electrostatic condensation.

Soluble salts, especially calcium sulphate, also damaged the stone. This gypsum may have had various possible origins and causes. The range of sources that may have introduced it include the canal water, the plaster coating, the moulding carried out in 1929, a bacteriological attack or the removal and rejoining of the upper part. All these moisture-based factors, along with the stone’s intrinsic characteristics, triggered various physicochemical deterioration processes.

First, the stone’s porosity led to water being absorbed and the calcium carbonate present in the stone being dissolved (AUGUSTI 1964). Second, the water was absorbed by the clay present in the

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stone. As the clay expanded, tension was created within the stone, which led to splitting.

These microfissures caused an increase in volume, generated by low temperatures and the freezing of the water absorbed by the stone. The contact between the feldspar and mica and the water led to the hydrolysis necessary to produce kaolinite and chlorite between the stratification planes, which created more clay, thus completing and restarting the cycle (VENDRELL, GIRÁLDEZ 2016).

All these processes formed a continuous cycle of deterioration, which manifested as a loss of

cohesion in the stone and separation of its outer layers.

At that time, various architectural procedures were considered, all of which were based on the need to insulate the portal from the outside and from the cloister area. Another idea was to separate the portal from the wall of the church (in order to create some ventilation) and to carry out the usual hardening processes, with synthetic products applied directly to the stone.

Apart from any architectural interventions, all direct restoration attempts carried out on the portal (proposed by specialists like Paul Coremans), based on wax or sulphur, on synthetic waterproofing or hardening products, and on silicates, were met with pessimism, as they were seen as just a temporary solution to the stone’s deterioration. Even methods that were more appropriate for stone materials, such as a limewater spray (proposed by Selim Augusti, director of the Naples Restoration Centre), could not alter the widespread opinion that the portal was destined to disappear.

After a series of studies and direct tests on the portal—some of which were rather absurd—with no positive results, it was clear that the key was in finding out the stone’s exact composition and the monument’s state of conservation. It was also evident that any intervention on the portal also required architectural intervention on its immediate surroundings.

For this reason, by ministerial order in 1963, a multidisciplinary committee was created, linked to the Juan de la Cierva Scientific and Technical

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1964 restoration, during which resin was applied with sprayer. Photo: J.M. Cabrera Garrido

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1964 restoration, during which the portal was protected with plastic, so that the resin solvent could evaporate slowly.

Photo: J.M. Cabrera Garrido

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Research Board, part of the Superior Scientific Research Council (CSIC in Spanish). This committee concluded that, given the stone’s characteristics, the main cause of the portal’s deterioration was water with high soluble salt content, along with changes in temperature and their consequences. They recommended insulating the portal from the ground below to avoid rising damp, through the introduction of a layer of lead, copper or polyethylene (this method was already being used in restorations all over Europe), and creating ventilation through the back of the wall, thus eliminating the salts.

THE 1964 RESTORATION AND ITS CONSEQUENCES

It was not until 1964 that, through the recently created Central Institute of Conservation and Restoration of Madrid (now the Cultural Heritage Institute of Spain or IPCE), the main restoration project was carried out, under the leadership of Alejandro Ferrant and José María Cabrera Garrido. This intervention would give the monument its current finish and influence its state of conservation for years to come. Its two main objectives were to harden the stone and to minimise the impact of moisture. One of the key stages of the project was determining which hardener would be most effective in consolidating the stone.

Based on the laboratory tests carried out by the CSIC, the conclusion was that the most appropriate hardener was Mowilith® 50 (2.5% dissolved in acetone and toluene), but tests on the portal provided unsatisfactory results, as the vinyl

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resin’s contraction index led to detachment of material (1968, Cabrera Garrido).

To deal with the stone surface’s fragility, Cabrera opted for another resin: the acrylic resin Bedacryl® 112X (2.5% in toluene), a methyl methacrylate used in similar treatments in Belgium, which he had discovered during his training the previous year. Although the results of the trials carried out were not ideal, the resin fulfilled its purpose of stopping the surface disintegration and did not colour the stone, unlike other hardeners, especially those derived from lime. Pressure from the media and politicians and the urgent need to act led to a decision to use a resin that did not clearly guarantee stability in the future.

Given the disintegration of the stone surface, the team chose to pre-harden it with Bedacryl®, but without removing the dust, as they would run the risk of getting rid of part of the sculpted surface. Although this solution meant that the relief of the sculpture would not be lost, it did cause the dust to be mixed with the resin, resulting in a darker colour. Eight layers of resin were later applied to ensure the stone was hard and consistent enough.

The year after the restoration, the portal was found to be in good condition; its response to moisture had matched expectations and no saline efflorescences had reappeared. It was thought that the stone’s problems lay in the crystallisation of salts on its surface (chlorides, sulphates and nitrates) in a very high concentration (33.7%), which was made worse by the irrigation canal

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Photograph of the portal from February 1963; the different tones show some of the consolidation tests carried out. Photo: J. Sanz, MAC-Girona

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New envelope on the portico, built between 1994 and 1995. Photo: CRBMC, 2008

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that flowed past it. For this reason, an action plan focusing on architectural and masonry tasks was created, with a view to minimising the deterioration mechanisms triggered by outside factors.

Many international specialists believed that covering the portal with an organic resin was detrimental to its conservation, as the material applied was incompatible with the original material. They called for the removal of the silicic acid from the sandstone. In spite of it all, the Bedacryl® had remained on the surface, as the dirt had not been removed, and its thickness varied depending on the area.

Just five years later, in 1969, experts warned that the portal’s stone was in poor condition again. On the lower areas (up to 1.5 m), the surface of the stone was beginning to disintegrate and new saline efflorescences were caused by moisture. Due to a lack of funding, the steps needed to insulate the portal from the outside properly had still not been made. It was clear that the solution consisted of closing off the atrium with windows

and altering the sanitation infrastructure around the monastery.

So, in 1971, a second restoration attempt was made on the portal, involving the fixation, cleaning and hardening of the sculpted surface and the extraction of soluble salts. Meanwhile, alterations were made to the sanitation around the site, ventilation channels were created behind the portal, the sides of the portal were sealed up to the church wall, the whole structure was stabilised and the top of the portal was fastened to the wall behind it. An archaeological exploration of the front was also carried out, focusing on waterproofing the roof and installing windows in the atrium; this was finished in 1972.

TOWARDS STABILITY: CLOSING OFF THE ATRIUM

In 1978, the Generalitat (the Catalan government) acquired powers over cultural policies and the preservation of Catalan monuments, including the monastery and the Ripoll portal. From then onwards, the Generalitat was directly involved in

DETAILS GENERIC CLASSIFICATION: sculpture | OBJECT: portal | MATERIAL/TECHNIQUE: sandstone, lime mortars and polychrome DESCRIPTION: architectural and sculptural piece, with polychrome relief | DATE/PERIOD: Romanesque, twelfth century DIMENSIONS: 7.14 × 11.54 m | LOCATION: western façade of the church in the Santa Maria de Ripoll Monastery (Ripollès) CRBMC REGISTER NO.: 3550 | COORDINATION: Pere Rovira | RESTORATION: Conservator-restorer team: Patri Amat, Albert Gaset and Rudi Ranesi (technical management and team leader), Eva Bermejo, Violant Bonet, Silvia Bottaro, Maria Cardenal and Sònia Murcia | DOCUMENTATION: Patri Amat and Rudi Ranesi (report). Patri Amat (maps) | PHOTOGRAPHY: Patri Amat, Ramon Maroto (CRBMC) and Verònica Moragas (Flare, SCP) | YEAR OF RESTORATION: 2016–2017

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the portal’s conservation, first through the Architectural Heritage Department, then through the Centre for the Restoration of Artefacts of Catalonia (CRBMC).

The 1980s saw the same recurrent issues surrounding the portal and its immediate environment. In 1985, the roofs on the basilica and on the atrium were still a cause for concern, due to their poor condition. They were therefore repaired again by the Girona Monuments Department. Another important step taken was the rechannelling of the irrigation canal, which was still causing serious damage, away from the portal.

In addition, CRBMC technicians carried out periodic maintenance work on the portal. However, the stone was still deteriorating irreparably, as proven by petrological studies carried out at the University of Barcelona by M. Vendrell and M. García (VENDRELL, GARCÍA 1992). Their conclusions were alarming. The growth of gypsum crystals inside the stone, which was causing alterations, was provoked by ambient moisture and dew. This was causing disruptions on the surface and in the resin and the loss of small fragments from the stone’s surface. Furthermore, the layer of resin was encouraging larger fragments to fall away.

This called for preventive conservation meas-

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ures focused on controlling the climatic conditions inside the atrium; the moisture that was still affecting the face of the interior wall needed to be removed, the atrium needed to be insulated and the roof needed to be waterproofed, as the current protection with windows was not sufficient.

So, faced with this evidence and media pressure, in 1994, the Catalan Department of Culture’s Architectural Heritage Department, led by Antonio Navarro, embarked on a daring, innovative preventive conservation project with a view to maintaining a stable interior climate, with humidity and temperature levels compatible with the portal’s materials. The Department’s technicians designed a more modern, watertight envelope, with UV filtering and a regulated climate control and air filtering system that displayed environmental data at all times through a remote control device.

This major preventive conservation project managed to stabilise the stone and stop it from deteriorating further. This gave experts time to organise various seminars, studies and analyses to determine the portal’s and its constituent materials’ real state of conservation and to carry out an exhaustive planimetric study of its deterioration, with high-quality scientific photographs.

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Plan of block A10: deteriorations.

Photo: Arcovaleno Restauro, SL and Patri Amat, 2013

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Plan of block A10: polychrome, patinas and interventions.

Photo: Arcovaleno Restauro, SL and Patri Amat, 2013

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The aim was to determine a definitive restoration process to follow, in order to deal with the resin’s alteration. In parallel, periodic maintenance and restoration tasks were carried out by what was then called the Department for the Restoration of Artefacts of Catalonia, led by Josep Maria Xarrié.

EXHAUSTIVE KNOWLEDGE OF THE MONUMENT

Between 2002 and 2016, a series of scientific studies were conducted to amass the knowledge needed for the portal’s conservation and restoration. The first study, carried out in 2002 by the CRBMC, represented the first estimation of the portal’s current state of conservation and identified the alterations made to the monument over its history, as well as most of its constituent materials (PORTA , ARTIGAU 2002). Later, in 2004, an exhaustive scientific analysis of its constituent materials was carried out (VENDRELL, GIRÁLDEZ 2008), along with various cleaning and surface treatment trials. Certain measures were proposed to improve the portal’s preventive conservation and suggestions were made regarding the conservation-restoration processes required to stabilise the monument. In 2008 and 2010, the same team conducted a qualitative analysis of the level of UV radiation that passed through the

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atrium windows’ filters and, later, carried out a critical analysis of all the interventions made on the portal.

In parallel, encouraged by the director of the Regional Cultural Services department, Miquel Sitjar, technicians from the Generalitat’s Department of Culture, along with the Bishopric of Vic and Ripoll Town Council, held meetings periodically in Ripoll to assess the monument’s overall conservation, using the existing information available on the portal (Olga Bas, Esther Colls, Maria Àngels Espona, Dani Font and Pere Rovira) and following the course of action set out by the CRBMC in 2008 (ROVIRA 2008). Within this framework, they determined that the first interventions needed to be made on the portal’s architectural and environmental surroundings, so that the stability of its container could be assured, before any restoration attempts on the stone itself. However, they also believed that, in the short term, after the relevant analyses, it was important to carry out conservation-restoration activities and eliminate most of the added resin, which was damaging and soiling the portal, and to restore the space inside the atrium.

For this reason, as part of the Romànic Obert programme (a collaboration between the La Caixa

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Foundation and the Catalan Department of Culture), in 2010, the Architectural Heritage Department repaired the atrium roof, while the Centre for the Restoration of Artefacts of Catalonia (CRBMC) examined the state of conservation of its arches, which had been altered greatly, as they were exposed to the weather. In fact, the damaged stone on the atrium was (and is) representative of how the portal would be without stable, protected surroundings.

This programme also involved the renovation of the climate control machinery, which had become obsolete. The climate inside the atrium was thus under control for another 20 years, through a continuous and alternating system made up of two air conditioning devices. All these interventions were essential in the preventive conservation of the portal. From this moment onwards, a conservation-restoration plan could begin to take shape.

To this end, in 2011, the director of the CRBMC, Àngels Solé, met with the heritage representative of the Bishopric of Vic, Father Josep Maria Riba, and insisted on the urgent need to restore the portal, with all the necessary preliminary studies and a conservation-restoration plan approved by scientific and institutional consensus, which was essential for a project of this magnitude.

First, an institutional committee was created, made up of Father Josep Maria Riba, heritage representative for the Bishopric of Vic; Jordi Munell, mayor of Ripoll; Albert Piñeira, head of the Monuments department at the Provincial Council of Gi-

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Face of the Maiestas Domini after restoration. Photo: CRBMC, 2017

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Cleaning tests being carried out. Manuel Iglesias and Rudi Ranesi. Photo: Patri Amat, 2015

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rona; and Àngels Solé, director of the CRBMC. This committee decided to organise an international symposium, “La portalada de Ripoll: creació, conservació i recuperació”, to discover and share knowledge of the monument around two main axes: the conservation-restoration of the monument and its artistic history. A scientific committee was named, with a view to defining the symposium’s programme and choosing presenters, and was made up of Lluís Bayona (Monuments Department at Provincial Council of Girona); Jordi Camps (National Art Museum of Catalonia); Manel Castiñeiras (Autonomous University of Barcelona); Francesca Español (University of Barcelona); Dani Font (Bishopric of Vic); Rudi Ranesi (Arcovaleno Restauro, SL); Pere Rovira (CRBMC); Marc Sureda (Episcopal Museum of Vic), who was the coordinator; Màrius Vendrell (University of Barcelona and head of Patrimoni 2.0), and Judit Verdaguer (Episcopal Museum of Vic).

The symposium’s conclusions in terms of conservation were resounding: a full restoration in

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Ultraviolet photograph.

A fluorescent white is given off by the layers that contain lead white and linseed oil. Photo: CRBMC, 2016

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accordance with current conservation-restoration standards needed to be carried out. Over 50 years had passed since Cabrera’s restoration, and the materials used had aged, the resin had darkened, the dust had combined with the resin and small alterations were beginning to appear on parts that had not been stabilised properly. Furthermore, studies suggested there were layers of medieval polychrome under the preserved pictorial remains, which experts were keen to recover.

Between 2012 and 2015, the CRBMC conducted various preliminary studies to identify the por-

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tal’s materials. To find out as much as possible, another analytical study—a rewrite of previous studies, the main aim of which was to analyse the resin and existing polychrome in more detail—a structural study, and a construction study were carried out (VENDRELL, GIRÁLDEZ 2012). From these and other analyses of the resin conducted in the CRBMC laboratory by chemist Ricardo Suárez, in 2013, the conclusion was that although the resin was altered, in its current environment, it remained inert and stable. Therefore, only the surface layer needed to be removed, as the resin was still playing an important role as a cohesive agent on the stone’s sedimentary grains.

TOWARDS A CONSERVATION-RESTORATION PLAN

The CRBMC was starting to put together a conservation-restoration plan with two clear objectives: to clean the ageing elements and to recover the portal’s aesthetic. With these goals in mind, in 2014, as well as an exhaustive photographic report and an orthophoto of the site, maps were drawn piece by piece to a scale that showed details of all the alterations that had occurred to the monument, so that precise information on the

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Plan that identifies and locates mortars. Photo: Arcovaleno Restauro, SL and Patri Amat, 2017

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portal’s alterations was available (AMAT, R ANESI 2014). This was the first process of its kind carried out on the portal.

Finally, to ensure an effective conservationrestoration plan, cleaning studies were carried out to determine the viability of removing the resins through laser cleaning and microblasting abrasive particles (IGLESIAS 2015). The conclusion was that no cleaning system could remove the resin on its own, and that chemical, mechanical and laser methods would have to be combined.

However, as well as removing the resin, there was another goal: to recover the preserved remains of the medieval polychrome. Evidence on the portal, analyses carried out and previous studies on similar monuments suggested that the portal was covered in polychrome from top

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Plan that locates interventions. Photo: Arcovaleno Restauro, SL and Patri Amat, 2017

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to bottom, like any other Romanesque sculpture. It was likely a polychrome made up of bright colours, a varied palette and a uniform tonality.

It was thought to be eye-catching and in keeping with the era’s tastes: a far cry from the grey, earthy colour of the damaged stone we can see now. The remains of the preserved polychrome layer on the portal were visible as a clean, uniform black layer—the last pictorial decoration on the portal—and suggested that there were remains of medieval polychrome underneath.

All the information gathered over these years of study revealed the portal’s exact state of conservation. All existing documentation was collected to create an overview of all the causes of alteration that had influenced its conservation, and potential cleaning techniques were studied.

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In 2015, through an agreement with the Bishopric of Vic, a conservation-restoration plan for the Ripoll portal, written by Pere Rovira with collaboration from Aleix Barberà, was presented to the Girona Heritage Commission. The clear aim was to clean the portal and recover its aesthetic unity by removing altered elements (specifically its resin) and stopping all deterioration processes.

Its boundaries were also well defined: they would not remove any more than was possible with the available conservation-restoration techniques.

The objective was to restore the monument to its former glory while respecting the original, to leave any invasive elements it was not possible to remove for the future, and to ensure enough stability to guarantee the portal’s future. All of this required an environment that was favourable to this type of intervention.

To achieve consensus between conservatorrestorers, heritage professionals and the scientific community, in 2014, the CRBMC proposed the creation of an expert committee, which would validate the preliminary studies and assess the viability of the proposed restoration plan. The expert committee was made up of Patri Amat

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Laser ablation cleaning process. Photo: Patri Amat, 2016

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ing to the conservation-restoration code of ethics and international charters), our intervention has been influenced by a unique, specific context, deriving from the monument’s characteristics and history.

In other words, the restoration of the Ripoll portal cannot be understood from a conceptual perspective without consideration of the criteria and materials that governed previous conservation-restoration interventions on the monument throughout its history. For this reason, attention must be paid to the work carried out on the portal in different periods, especially the most technical aspects. (conservator-restorer), Concha Cirujano (Cultural Heritage Institute of Spain, IPCE), Manuel Iglesias (University of Barcelona), Lorenzo Lazzarini (University of Venice), Rudi Ranesi (Arcovaleno Restauro, SL) and Pere Rovira (CRBMC). This committee would monitor the burgeoning conservation-restoration process.

Pere Rovira

RESTORING THE RIPOLL PORTAL. PRELIMINARY STUDIES

Within the field of art history, the Ripoll portal is a key Romanesque sculptural piece. It is perhaps the most representative element of the symbolic and ancestral weight of Catalan art at its origins.

This combined with its intrinsic fragility, due to the nature of the Bellmunt sandstone from which it is made and the difficulties it has suffered over its history, has made the portal, as explained by Pere Rovira on previous pages, the subject of a series of restoration attempts from the 1960s onwards and a guinea pig for various consolidation technique tests and experiments. For this reason, the Ripoll portal has become an iconic monument in the history of stone conservation-restoration.

In this regard, as well as aiming to fulfil criteria common to all conservative interventions (accord-

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OBJECTIVES, CRITERIA AND COURSE OF ACTION

The first step was to determine which materials were to be preserved and which were to be removed, in order to fulfil the main objectives of preserving the monument’s history and of recovering the aesthetic unity of this work of art.

Given that the climate control in the atrium already ensured that the constituent materials were relatively stable, the intervention undoubtedly focused on recovering the portal’s expressive and communicative capacity, so that its beauty (which had been visibly compromised before the intervention) could be appreciated once again.

In accordance with this goal, the intervention needed to free the portal from the weight of the materials that had been applied to the stone with the intention of saving it but that had ended up interfering with the correct interpretation of the monument. The work of previous interventions, therefore, had to be reversed. The main challenge consisted of finding the right balance and synthesis between removal and preservation.

Preliminary studies, which focused on diagnosing and mapping the alterations that had affected the portal and identifying the materials applied to the stone (mortars, patinas and hardeners), had paid special attention to defining the technical criteria for the cleaning process.

These preliminary studies—which would later be complemented by contributions from an expert

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committee, and by the tireless work of a team of restorers who examined the monument and calibrated and combined the best combination of methodologies for an optimal result—stemming from an interdisciplinary collaboration between professionals from various fields, determined that the ideal level of cleaning was not a complete removal of old hardeners (besides, this method would not be viable). A “gentle” cleaning guaranteed a satisfactory result from an aesthetic perspective and avoided putting the stone at risk, as the hardeners were partially holding it together.

Cleaning trials pointed to the viability of two cleaning systems: the microblasting of abrasive particles and physical cleaning with laser technology. Both techniques provided satisfactory results that did not harm the original materials if they were applied at a certain pressure, energy and distance from the stone. As we will see later, each system was best in a certain context, depending on the area’s needs.

Furthermore, over the course of the trials, the team found that the Bedacryl® resin (applied to the stone as a hardener by Cabrera in 1964) was soluble in acetone, which led to the addition of a third cleaning system: chemically removing the resins, artificial patinas and dirt through the application of acetone swabs.

Defining the methodologies to be used was just the first step; as we have seen, the amount of material to remove was still to be decided, within the scope of the intervention’s conceptual legitimacy.

It was therefore necessary to reflect critically on selective removal, given the irreversible nature of the cleaning process.

The decisions made over the years in terms of reintegration mortars contribute towards better understanding of this point. The repairs made from the late nineteenth century especially, which were supposed to stabilise the stone and fill in holes, caused interference in the interpretation of the relief, as the mortars often spilled over the original. Other modern repairs were carried out with Portland cement. Therefore, whether for aesthetic reasons or due to incompatibility with the original materials, both of these products had to be removed.

However, the presence of lime mortars, which had also been used for restoration purposes but significantly earlier (possibly in the Gothic period), raised other issues. These mortars may have been applied to fix the damage caused by the Candlemas earthquake of 1428. It was therefore essential to take into account their age and their links with a key event in the monastery’s history.

Meanwhile, it was also relevant that the mortars were of a high quality, that they were integrated aesthetically into the monument and that they still fulfilled their purpose as a filling between the

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Removal of the black monochrome layer through microblasting.

Photo: Verònica Moragas, 2016

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Dissolving the resin with acetone, with the help of paintbrushes and cotton swabs. Photo: Patri Amat, 2016

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open joins between stone blocks at the top of the portal, which had been moved by the earthquake.

In this case, it was decided that they would be preserved.

There were similar issues surrounding the interpretation of reintegrations with stone materials. This method was used by Elies Rogent in the second half of the nineteenth century and was supposed to recover the portal’s architectural forms. It mainly affected the top of the monument, which had been partially lost in the years in which the monastery was abandoned, following the events of 1830. These reintegrations, proof of a historically significant intervention, were carried out with the same Bellmunt stone carefully and faithfully to the original; they therefore aid interpretation of the portal and contribute towards recovering the expressive unity of this work of art.

Therefore, they were to be preserved.

The same did not go for the preservation of the artificial patinas present all over the architectural and sculptural surfaces. These patinas, which were supposed to mask the defects from previous interventions, were applied rather shoddily and at random; they altered the appearance of the original stone and caused considerable interference in the interpretation of the piece.

A more complex dilemma was whether or not to preserve the relatively modern black monochrome layer, which has been partially preserved in the middle of the portal. Analyses carried out in 2012

by Patrimoni 2.0 determined that it was a paint with organic binder, made with great skill. This definitively disproved the most widely repeated hypothesis at the time, which was that the black

colour was caused by soot left on the stone from the fire of 1830.

Actually, as confirmed by ultraviolet photographs and stratigraphical analyses, this black polychrome hid remains of older polychrome layers, such as the skin on the main figures’ hands and faces. This hidden polychrome raised the question of whether or not the black monochrome layer should be removed to reveal the colours underneath.

To make a decision on the subject, it was first necessary to find out whether it was technically possible to remove the black layer without damaging the polychrome underneath. To do so, first, the relevant colour solubility tests were carried out, without success. However, microblasting tests did offer positive results. The possibility of recovering the old polychrome through a risk-free mechanical system had therefore emerged.

Apart from the technical aspect, though, the conceptual viability of the intervention also had to be assessed. On one hand, the irreversible nature of the process needed to be considered; the black layer, proof of an intervention carried out with aesthetic intentions in an uncertain time with an unknown purpose, would be gone forever. On the other, the importance of recovering the old polychrome, and therefore the supposed original unity of the piece, had to be taken into account.

In the end, a third, intermediate option was chosen: to remove the black layer only where it was covering older polychrome (concentrated around the faces and hands of the Christ in Majesty and the angels) and preserve it on other parts of the portal, where it was not covering other lay-

TIMELINE Years 838 Privilege granted over the waters of the Freser River,

construction of the Santa Maria or Molinar irrigation canal 888 Consecration of the first church 1032 Consecration of the fourth church by Abbot Oliba Around 1150 Construction of the portal 1280–1310 Construction of the portico 1359–1362 Abbot Jaime Vivers builds the Sant Vicenç chapel at the western end of the portico 1377 New entrances to the church paid for by sexton N. Umbrells 2–3 February 1428 Earthquake causes the central nave and one of the bell towers to collapse 31 October 1410 – 1 December 1439 Gothic reconstruction of the central nave by Abbot Dalmau of Cartellà 15 May 1432? Reconstruction work on the church begins 1463 Invasion and pillage of the monastery by Pere Rocabertí’s troops

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11–17 June 1794 French revolutionary troops’ raid on the church and Ramon Berenguer ıv’s tomb

1826–1830 Church remodelled in a neoclassical style, interior

plastered and building reduced to three naves by José Morató 9–11 August 1835 Fire in the monastery and pillage by liberal Miquelets, decapitation of the Saint Peter statue and part of Saint Paul (and possibly fragments of other statues) 27 May 1839 Attack on the town of Ripoll by the Carlists Around 1840 Loss of the portico’s roof 1846 Collapse of the abbot’s palace tower 1847 Destruction of the north-east gallery of the cloister Between 1852 and 1855 Collapse of the main nave and the gospel nave 1850 First investment into the monastery of 8,000 rals by the Central Monuments Commission of Madrid 1861 Collapse of the last remaining part of the vault

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ers of paint. This solution meant that the presence of this black colour on the portal could be studied in the future.

As we will see later, the decision to remove part of the black monochrome layer may be considered wise, judging by the positive results obtained: as well as the skin tone, the details on the figures’ eyebrows and red lips and the golden colour of Christ’s beard and hair were also revealed. Other rich, unexpected details appeared on Christ’s face: the black lines revealed on the cheeks, just above the beard, contour the face and highlight its features, while the wisps on the neck, painted in a dark colour, create the effect of the shadow from the afternoon sun, cast by the curls of the beard.

Painting and sculpture enter back into dialogue, as they did when the original monument was created, and enable us to appreciate the archetypal beauty of the figure of Christ as an ancient icon: an ageless face expressing both youth and wisdom, both moral determination and mercy to anyone contemplating the figure, the same way today as it did in the Middle Ages.

cleaning and the use of soft brushes of various sizes.

This initial phase allowed for a first close-up look at the monument; the team was able to identify the precise location of existing alterations, detect the weakest points and locate possible polychrome remains. The new information collected complemented the maps of alterations drawn up in the preliminary study on the portal’s state of conservation, carried out in 2014.

Once the general and specific criteria that would govern the restoration were defined, it was time to begin the work phases; these and the procedures and materials used will be described below.

Mechanical cleaning of the upper part of the portal Both the upper part of the portal and the infill in the architectural structure presented a significant accumulation of dust, sediment, soot, bird excrement and other elements.

First, vacuum cleaners and brushes were used to remove the deposits accumulated inside the infill; great care was taken not to remove any material that may provide information on the portal’s construction.

Next, the excrement and deposits attached to the upper part of the monument were removed mechanically with a scalpel, either dry or with the help of a hydroalcoholic solution (1:1) to soften any build-up. This cleaning process revealed incisions that identify the pieces of the cornice substituted during Elies Rogent’s restoration (1865–1893).

Elimination of surface dust First, a gentle cleaning of the surfaces was conducted, which consisted of mechanically removing surface dirt and remains of detached sediments.

The intervention involved controlled vacuum

Removal of mortars and lime slurry One of the most significant steps was removing most of the mortars added throughout the monument’s history. The majority of these mortars had been analysed by Patrimoni 2.0 in 2012 and could

CONSERVATION-RESTORATION INTERVENTION

24 September 1861 First estimates made for the restoration

of the portico roof and the bell tower by Elies Rogent 1865 Repair of the atrium roof with design by Elies Rogent 1866 Construction of the textile factory next to the site 1867 First photographs of the monastery 12 March 1878 Agreement between the Girona Provincial Monuments Commission and F. Graells to mark the boundary with the factory, divide the Santa Maria irrigation canal (in front of the portal) into two and build a syphon 1885 Transfer of the remains of Ripoll Monastery to the Bishop of Vic, Josep Morgades 21 March 1886 Start of the restoration work led by Elies Rogent 1 July 1893 Consecration of the basilica by Bishop Morgades 1928–1929 Attempt to make a mould of the portal 1938 Stone wall built by the Generalitat to protect the portal 1955 Paving of the square outside the monastery

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26 September 1959 Article entitled “La portada en peligro” published in El Ripollés, causing widespread alarm

Octubre 1959 Symposium Internacional de Restauración Monumental (Madrid–Barcelona)

January–May 1961 A. Ferrant opens up two holes, one at the

extreme right of the portal and one on the left, to check for rising damp. Four pits in the church wall are explored back to the infill (1.8 m thick) June 1961 M. Chamoso Lamas and A. Sanmartín carry out consolidation tests with wax and sulphur, after the stone is warmed up October 1961 Consolidation tests with limewater carried out by S. Augusti. Extraction and analysis of Ripoll stone 1962 Marc Weber applies an acrylic resin to block F3 24 February 1962 Analytical study by Selim Augusti: Relación sobre la naturaleza, el estado y las condiciones del material de piedra que constituye la materia prima de la portada y del claustro de la basílica del monasterio de Santa María de Ripoll

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be divided into two main groups: lime mortars, on the upper registers, and the mortars on the sides and at the bottom of the portal, which were generally Portland cement.

As explained in the criteria section, the Portland cement was removed, along with the lime mortars that clashed aesthetically with the original and that had been applied clumsily. All the mortars, both those that were removed and those preserved, were identified and mapped for posterity. They were removed mechanically, with manual tools (scalpel, chisel and hammer) where possible, though where the mortars were at their thickest, pneumatic tools were also used (vibrating cutters).

Almost all of the removed mortars had been applied before the Bedacryl® was applied in 1964.

For this reason, once they were removed, areas not penetrated by the acrylic resin were revealed; in some places, there were localised losses of cohesion in the stone, resulting in disintegration.

White dots also appeared on the stone when the mortars were removed. These were identified

by Patrimoni 2.0 as saline efflorescences. These gypsum crystals were spread all over the portal and may have been caused by the metabolic activity of bacteria growth, potentially encouraged by the organic resin.

Scientists determined that the gypsum did not pose a damage risk to the stone, as its quantity was limited and the controlled environment around the portal prevented it from growing. The bacteria was also harmless, as it would be eliminated when the surface resin was removed with solvents.

June 1962 Francis J.L. Dorl carries out consolidation tests on

samples from an experimental procedure on the cloister’s cymas and “non-endangered” parts of the portal August 1963 Dr. Iñigo Leal conducts an analysis of the portal’s condition. A bacteriological study is undertaken September 1963 By Ministerial Order, a committee of eight specialists linked to the Juan de la Cierva Scientific and Technical Board is created to study the disintegration of the portal and carry out consolidation trials: Cabrera and S. González-Babé November 1963 Vogt proposes cleaning the surface with Kessler fluorinated polymers, hardening it with fluosilicic acid and later soaking it with alkaline silicates January 1964 Artur Kratz visits Ripoll and writes a report recommending the portal be taken apart and the gap be soaked with silicates and fluorinated polymers

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The removal of these added materials also revealed interesting, never-before-seen construction details, including wooden wedges and place markers, which suggest that, at some point, the cornice at the top of the portal may have been taken apart, at least partially.

Finally, the metal elements embedded into the stone were also removed, including the bolts inserted into the head of the Christ in Majesty, which probably used to hold a restoration fragment that has now disappeared.

Removal of attached dirt and the surface resin In 1964, Cabrera began the pre-hardening process with the application of four layers of Bedacryl® 122X (2.5% in toluene) to the stone. The stone was later cleaned with soft brushes, but some of the dirt had unintentionally been combined with the resin.

For this reason, the portal’s surface presented an accumulation of dirt and deposits, which had adhered to the resin to varying degrees depending on the area. Some blocks presented little surface resin and little or moderate amounts of dirt attached to the resin. Others displayed great amounts of surface resin, as well as a considerable accumulation of deposits and sediments stuck to the resin.

The first cleaning trials, which were carried out on the portal in 2015, aimed to remove the dirt through two processes—physical and mechanical—and offered rather positive results: - The physical and thermomechanical cleaning through laser technology (laser ablation) re-

22 January 1964 Publication of Estudio de la infección

bacteriana de la portada del monasterio de Santa María de Ripoll, by B. Iñigo Leal 11 May 1964 Gregorio Ramón Cebrián and Mr. Guevara apply a hardening product on the portal, identified by Patrimoni 2.0 as sodium and potassium silicate May 1964 Agustín Rafart carries out consolidation tests on a sample with varnish and a finishing patina made of beeswax and turpentine 6–25 November 1964 Central Conservation and Restoration Institute: 1st phase: cleaning and hardening of the portal with Bedacryl® 122X 8–10 November 1965 Symposium in Madrid on the alteration of stone materials used in monuments July–September 1971 ICCR 2nd phase: fastening of the portal, cleaning of the rear part, waterproofing of the roof and removal of rising damp

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moved the deposits attached to the Bedacryl® 122X, without affecting the resin.

- The mechanical cleaning through microblasting aluminium oxide utilised the impact or friction of the abrasive particles to remove the deposits attached to the Bedacryl® 122X, with some superficial effects on the resin.

However, it must be noted that although the cleaning study was exhaustive, it was not entirely representative of all the variables the monument presented (the varying degrees and intensities of the dirt, the variable state of the stone, the presence of materials added in previous interventions, etc.). For this reason, in the early stages of the intervention, various cleaning techniques were calibrated, according to the area of the portal.

The cleaning process was monitored by Dr. Manel Iglesias at all times, and the figures set out in preliminary studies were respected.

During the trials, it was found that acetone could dissolve the chromatic patinas and excess acrylic resin. Scientific analyses confirmed that it partially removed the resin—just the excess on the surface.

So, the definitive solution was the use of three cleaning systems. The choice of one method or another depended on the characteristics of the surface to be cleaned: the stone’s state of conservation before 1964, the amount of surface resin, the amount of dirt and deposits, and the presence or absence of patinas.

Although, in certain areas, different cleaning systems were combined to achieve a homogeneous result, the following guidelines were established:

— 1. Physical cleaning with laser technology (laser ablation) offered good results in areas with little surplus Bedacryl® 122X on the surface and a small or moderate amount of dirt attached to the resin.

This was carried out with the Art Laser-Lambda SpA model of the Nd:YAG (1064nm) Q-Switch® laser tool. The settings used were 200–250 mJ of energy, 20–30 Hz of frequency, and 45–55 cm of distance, with an exposure time of less than 10 s/ cm2 at all times.

Scientific monitoring of the process ensured that, by respecting these figures, the maximum fluence of 1.21 J/cm2 established during preliminary studies was not exceeded; the stone was therefore left unaltered.

February–March 1973 ICCR 3rd phase: portico closed off with

windows and controlled artificial ventilation 1988–1992 Maintenance, control and cleaning work carried out on the portal by SRBM (Department for the Restoration of Artefacts) technicians 1992 The Cartographic Institute makes a photometric record and sketch of the portal 1992 Thermohygrometers installed 1992 State of conservation study by M. Vendrell and M. Garcia: Portada Romànica de Ripoll. Estat de conservació i mecanismes de degradació 1993 Maintenance, control and cleaning work carried out on the portal by SRBM technicians 1993 The Architectural Heritage Department is tasked with the conservation, management and maintenance of the portal 1994–1995 Architectural Heritage Department: New portico envelope and installation of a climate control, refrigeration, dehumidifier and air filtering system

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Injection of liquid mortar to stabilise a loose fragment.

Photo: Patri Amat, 2016

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1996 Maintenance, control and cleaning work carried out on the portal by SRBM technicians

1996 Restoration of the lion on the left of the portal, removal of an iron bolt: J. Pey (MNAC)

1997 Annual monitoring of environmental data by Patrimoni UB 2000 Installation of a UV ray filter on the glass envelope 2002 Conservation and restoration study by E. Porta and

M. Artigau: Estudi de conservació de la Portada de Ripoll 2002 Restoration interventions: desalination of figure E9, removal of foreign elements, hardening with Paraloid® 5%, installation of a datalogger October 2004 Study on the portal’s conservation. Patrimoni UB: La portada Romànica de Santa Maria de Ripoll. Antecedents històrics i analítics, estat de conservació, assaig de neteja, suggeriments de restauració, propostes de futur

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2. Mechanical cleaning with microblasting of aluminium oxide, meanwhile, was more appropriate in areas with a lot of Bedacryl® 122X on the surface, as long as the stone underneath was stable.

In the archivolt area, where the stone presented little deterioration but an excess of resin, there was a several-millimetre-thick layer of Bedacryl® 122X and even occasional drips. In this context, laser cleaning was not appropriate, as it altered the colour of the resin-coated surface, turning it a grey-green shade. Microblasting aluminium oxide particles, meanwhile, removed part of the surface resin efficiently and quickly and posed no risks to the stone below, as it was strong in these areas.

The device used for this process was the CTS 1 microsandblaster. In this case, the parameters used were those recommended by M. Iglesias: a projection distance of 10 cm, an angle of 90°, a maximum pressure of 2 bars and an approximate time of 2 s/cm2. The chosen particle was aluminium oxide of grain size 63 µm. However, with this method, the surfaces were whitened slightly due to the superficial damage to the resin and the resulting change in how it reflected the light. This whitening did not pose a problem, though, as it could be reversed easily through the application of an acetone spray, which would dissolve the remaining resin.

3. Physicochemical cleaning with acetone was highly useful in areas where both excesses of Bedacryl® 122X on the surface and significant quantities of attached dirt had to be removed.

This system was mainly used on horizontal sur-

2007 The Centre for the Restoration of Artefacts of Catalonia

(CRBMC) takes on the conservation, management and maintenance of the portal April 2008 Qualitative analysis of UV radiation filtering.

Patrimoni UB: Anàlisi qualitativa de la capacitat de filtrat de la radiació ultraviolada dels vidres del nàrtex de la portada de Santa Maria de Ripoll July 2008 CRBMC: writing up of the Portal Conservation Plan project 2009 Girona Regional Services and CRBMC: Miquel Sitjar creates the Ripoll Portal Master Plan Monitoring Commission, which will implement the Master Plan February 2010 Critical analysis of previous interventions.

Patrimoni UB: Anàlisi crítica de les intervencions de restauració en la portada de Santa Maria de Ripoll 2010 CRBMC: renewal of the climate control, refrigeration, dehumidifier and air filtering system machinery (‘Romànic Obert’ programme)

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faces and areas where the stone was disintegrating the most. The result was very similar to the one obtained through microblasting, although the acetone was more effective in removing the resin from between the grains.

This method involved two means of applying the solvent: by applying cotton swabs and by rubbing the surfaces with soft brushes and acetonesoaked swabs. In some areas, when there was dirt under the resin, this chemical cleaning was complemented with subsequent laser cleaning.

Finally, as we will see below, cleaning with acetone was effective in removing the incongruous chromatic patinas from the portal.

Removal of patinas To remove the patinas, various systems were used: • On the substituted blocks in the cornice, where the patina presented a preparation layer below, the patina was removed successfully through mechanical systems, including scalpels and small pneumatic tools.

• The blocks where the patina was applied directly onto the original stone required physicochemical cleaning with acetone on a cotton swab to remove the layer of paint.

Removal of other hardeners The various hardener products present on the stone applied during the various consolidation tests carried out before the 1964 restoration, including wax, calcium hydroxide and sodium and potassium silicate, were treated individually according to their characteristics.

2011 Renewal of the portico’s roof 2012 CRBMC – Arcovaleno Restauro, SL: laser cleaning tests 2012 Study on the portal’s state of conservation by Patrimoni 2.0:

2013 2013 2014 2015 2015 2016

Santa Maria de Ripoll, Portada. Estudi dels materials de formació, acabat i decoració, estat de conservació, intervencions antigues i suggeriments de conservació CRBMC and Arcovaleno Restauro, SL: surface cleaning and complete diagnosis of the portal International Symposium on the Ripoll Portal Creation of an expert committee to study and assess a portal restoration plan Manuel Iglesias carries out the Anàlisis dels paràmetres de neteja amb làser i microprojecció d’abrasius dels materials petris de la portalada de Santa Maria de Ripoll

By CRBMC: writing up of a draft for the portal conservationrestoration proposal Portal restored by Arcovaleno Restauro, SL, led by CRBMC

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Block B6 with all cracks sealed.

Photo: Patri Amat, 2017

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1. Intervention in areas with wax In June 1961, Sanmartín carried out a consolidation test on the stone, applying wax with sulphur after warming the stone surface with a blowtorch.

This process changed the colour of the stone’s surface and caused the wax to penetrate deep down into the stone.

Therefore, in the recent intervention, once the surface resin was removed with acetone, only the excess wax on the surface could be removed with a scalpel.

Then, efforts were made to mitigate the colour changes and make the surface uniform; laser cleaning was used to clean the parts where the wax had darkened the stone.

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Blocks B4/B5 with filler mortar applied. Photo: Patri Amat, 2017

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2. Intervention in areas with calcium hydroxide Also in 1961, Selim Augusti conducted tests with calcium hydroxide on some of the cloister’s capitals, with positive results. Later, he instructed his team to apply this methodology all over the portal.

However, a mistake made by one of the workers meant the limewater was applied too thickly. As the calcium hydroxide dried, the lime stayed on the surface and formed a lime slurry-like white film. This led to various coloured patinas being applied at different times to restore the affected areas.

In this case, acetone was used again to dissolve the acrylic resin on the surface. Part of the

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Sponge being used to give texture to finishing mortar.

Sand is favoured over lime. Photo: Patri Amat, 2017

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calcium hydroxide layer was dissolved with the resin, but lime nodules remained in the gaps in the stone. These were removed mechanically with a scalpel.

3. Intervention in areas with sodium and potassium silicate The restoration attempt made by G. Ramón Cebrián in 1964 consisted of applying sodium and potassium silicate. These products, which were used widely as a stone hardener in the 1970s, accumulated on the surface and formed a hard, opalescent layer. For this reason, after they were applied, patinas were introduced so that the monument was uniform.

In 1965, Cabrera noticed white crusts appearing on the stone’s surface. From the 1980s onwards, saline efflorescences were witnessed.

During the intervention by E. Porta and M. Artigau, analyses concluded that they were made of sodium chloride and calcium sulphate, so a desalination process was carried out.

In this intervention, the system used to remove the potassium silicate was the microblasting of aluminium oxide, with the device and parameters described above.

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Recovering the polychrome The monochrome black layer, studied by Patrimoni UB in 2012, consisted of a paint layer made up of a carbon black pigment, potentially mixed with calcite, gypsum, clay and quartz; an organic binder of animal origin (identified through the presence of phosphorus); and a lead drier.

Once the myth that this black colour was produced by smoke from the 1830 fire had been debunked, it was obvious that this layer, despite the question marks around its age, had been applied for decorative purposes.

Another highly relevant aspect of this monochrome layer was that it was partly masking other, older, possibly original polychrome, which was of greater interest as it could reveal the portal’s original aesthetic. As mentioned, the parts with this older polychrome were concentrated around the main figures’ skin and Christ’s halo.

Analyses were carried out on this older polychrome and concluded that the skin colour was made with lead white, vermilion and whiting (calcite) or gypsum, with an oil drier as a binder.

Ultraviolet photographs identified these areas, through the fluorescence that occurs from the reaction between lead white and linseed oil.

The gold colour on Christ’s hair, beard and halo was also analysed. The colour on the beard and hair was made up of gold leaf, mordant, lead white, tree resin and oil. The halo, meanwhile, was made with metal leaf containing an alloy of lead and tin. On top of this leaf, a more recent mixture was detected, made up of lead white, verdigris, copper carboxylates, kaolinite, calcite and a drier oil.

The polychrome issue was studied closely by the expert committee, who concluded that the black layer was to be preserved generally, as a testament to the era’s decorative intentionality, but that the parts that covered an older polychrome layer were to be removed.

Once these criteria were established, the solvent tests proposed by Cremonesi and Wolbers were conducted to find out how to dissolve the black layer, with unsatisfactory results. This led Lorenzo Lazzarini (member of the expert committee) to think that the paint’s binder may have been casein. With this hypothesis as a starting point, the cleaning tests incorporated physical and mechanical systems: Laser cleaning achieved extraordinary results around Christ’s hair and beard; this system was effective and harmless and respected the substrate to be preserved. Scientific analysis of this cleaning method confirmed that the gold layer had not been affected, despite some remnants of the black colour in the cracks.

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However, this physical cleaning method could not be used on the skin areas or parts with pewter, as the laser would darken any pigments or materials that contained lead. So, on the skin and halo areas, the most appropriate system was microblasting with aluminium oxide of grain size 63 µm, carried out with a high-precision microsandblaster. The device used was the MR-1 model

by MESTRA. In this case, the parameters used were a projection distance of 10 cm, a projection angle of 90°, a pressure of 0.3–0.6 bar, and an approximate time of 4 s/cm2.

Stabilisation and reintegration of the stone The process of stabilising and reintegrating the stone, which aimed to improve conservation conditions and interpretation of the piece, were governed by a policy of intervening as little as possible: the application of products to the stone was restricted, unnecessary reconstructions were avoided, and the materials used were as compatible with the original materials as possible.

1. Hardening the stone substrate In localised areas, the removal of added mortars, which had partially covered the stone, caused some stone fragments to disintegrate. These areas, which were generally near the joins, needed to be strengthened to ensure the cohesion of the stone.

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Chromatic reintegration of the mortars.

Photo: Verònica Moragas, 2016

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Once several options had been assessed, it was decided that the best solution that would guarantee the continuity of the materials was to harden these areas with the acrylic resin used in 1964. The existing Bedacryl® 122X on the monument was still in an optimal state of conservation and was still highly soluble 50 years later.

This acrylic resin, made up of n-butyl methacrylate (40% in xylene) and soluble in aromatic hydrocarbons, esters and ketones, achieved good results when tested: it displayed quick absorption, optimal drying and effective hardening.

Therefore, the hardening method used was the application (using a brush) of a Bedacryl® 122X solution (2% in xylene) as several layers (in one session) until the disintegrating particles were stable again.

2. Stabilisation of fragments and splitting Certain localised fragments of the stone presented some movement. To stabilise these fragments and prevent them from detaching, a liquid hydraulic lime mortar was injected, after the area was moistened with a hydroalcoholic solution, to fill in any gaps and/or cracks.

In addition, the whole portal presented splitting of the stone’s surface layer, in the form of films, scales, flakes and blisters of various sizes. All of these areas needed to be sealed to stop the mate-

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rial detaching and to prevent dust deposits from other deteriorations.

These small openings were closed using a hydraulic mortar of very fine grain size, which was applied with a small spatula after the substrate was moistened. This mortar was finished with a sponge, so that the surface lime could be removed and a texture and colour similar to the original stone could be achieved, thanks to the mixture of aggregates in the mortar.

3. Adhesion of fragments Some small stone fragments attached in previous restorations came loose during the chemical cleaning process, as the acetone dissolved the resins used.

These fragments were reattached with Mowital® B 60HH resin, a polyvinyl butyral widely used to glue and strengthen ceramics that displays good reversibility, resistance to ageing, transparency, adhesion time and retractability.

4. Volumetric reintegration In terms of reintegrations carried out on the portal to improve its aesthetic dimension, the reconstruction of fragments was avoided at all times.

This reintegration was limited to closing joins between blocks and sealing cracks, in order to guarantee the monument’s volumetric continuity.

Depending on how deep the crack was, one or two types of mortar were applied with a spatula, after the substrate was moistened.

In the deeper joins and gaps, a filler mortar was applied first. Given the controlled environmental conditions around the portal, this filler mortar had to be relatively soft and porous, to allow the stone to breathe. For this reason, the mortar was made from a combination of hydraulic and air lime, plus pumicite as part of its aggregate composition.

A finishing mortar in a neutral colour was used and finished with a sponge, so that it would blend in with the tones of the stone all over the portal.

5. Chromatic reintegration Finally, due to the tonal variety around the monument, the reintegration mortars underwent a treatment based on chromatic glazes to make the piece uniform and aid its interpretation.

These glazes were made from an alcohol and acetone solution (1:1) mixed with natural pigments (Havana ochre, natural umber, toasted sienna, terracotta and ebony black). This glaze was either brushed or sprayed on (especially for large holes).

Patri Amat and Rudi Ranesi

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PREVENTIVE CONSERVATION AND MAINTENANCE

The conservation-restoration project carried out and described in the previous section was entirely necessary and, as well as recovering the portal’s aesthetic, has stabilised the monument and rectified previous interventions. But the conservation of this monument does not stop here: we are now entering a stage in which conservation is prioritised over restoration.

Preventive conservation aims to reduce and minimise artefacts’ deterioration through a systematic work methodology that identifies, assesses and monitors the risks that affect them.

The fundamental strategy involved in this approach is to eliminate or minimise these risks through continued efforts over time. The goal is to act on the origin of the problem, which generally derives from factors outside the artefact itself, and to prevent it from deteriorating further or being lost forever. The scope of intervention is therefore vast.

In the case of the Ripoll portal, once the conservation-restoration project carried out between September 2016 and February 2017 was finished, it was time to define a preventive conservation strategy. This strategy required consideration of concepts like sustainability—through the optimisation of technical, human and financial resources—and accessibility, in terms of putting cultural artefacts within the public’s reach.

At the CRBMC, a host of professionals were involved in collecting and processing information to create the Preventive Conservation Plan (PCP), which defines a series of short- to long-term conservation objectives. The PCP has become a tool to manage the artefact and elements of its immediate surroundings from a conservation perspective.

Once a risk assessment is carried out, the Plan sets out a course of action to monitor these risks and their corresponding protocols (monitoring of state of conservation, cleaning of the space, use of the space for cultural visits, monitoring of environmental conditions, etc.). The Plan also defines guidelines for solving any problems or risks that may arise occasionally.

The various maintenance protocols aim to organise periodic maintenance tasks and systematise processes, in order to ensure optimal monitoring and tracking. Through data collection and a systematic monitoring process, assessments can be made with a view to optimising resources and results and, therefore, improving how the Conservation Plan is implemented. The Preventive Conservation Plan is a living, open document, and is therefore being reviewed constantly.

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As a first step towards success, administrative and technical structures have been defined to guarantee the smooth running of the methodology established in the Plan. All that is left is its practical implementation and provision of the necessary resources.

The activities to be carried out include periodic maintenance of the artefact and the space, with removal of any dust deposited and reviews of its state of conservation; monitoring of both natural and artificial light; control of visitor flow; and improvements to safety measures to avoid potential risks.

There is another important task linked directly to the artefact’s conservation: dissemination and knowledge. Only with the public’s awareness, collaboration and commitment can a preventive conservation process be successful. The proper use of any cultural artefact, respect, and the belief that it belongs to us all are essential in conservation.

From now on, it is everyone’s responsibility to put the wheels in motion and implement the measures that will protect this artefact and enable us to enjoy it for years to come. Conservation is down to us all.

M. José Gracia

Bibliography AMAT, P.; R ANESI, R., Estudi de l’estat de conservació de la portalada de Ripoll: examen organolèptic. Plànols i anàlisi de les degradacions, alteracions superficials, pàtines i policromies i intervencions anteriors, March 2014.

AUGUSTI, S., “Relación sobre la naturaleza, el estado y las condiciones del material de piedra que constituye la materia prima de la portada y del claustro de la basílica del monasterio de Santa María de Ripoll”, in Informes y Trabajos del Instituto Central de Conservación y Restauración, no. 1, Ministerio de Educación Nacional. Dirección de Bellas Artes, 1964, p. 18.

BARRAL, X., “La sculpture à Ripoll au XIIe siècle”, in Bulletin Monumental, vol. 131, no. 4, 1973. p. 316.

BARRAL, X., “Le portail de Ripoll. État des qüestions”, in Les cahiers de Saint-Michel de Cuxa, no. 4, May 1973, p. 153.

IGLESIAS, M., “Anàlisi dels paràmetres de neteja amb làser i microprojecció d’abrasius dels materials petris de la Portalada de Santa Maria de Ripoll (Ripollès). Fase 1; Fase 2; Discussió, i Conclusions”, Barcelona, December 2015.

LLAGOSTERA , A., “Vicissituds. Portada romànica de Ripoll” in ALIMBAU, S.; LLAGOSTERA , A.; ROGENT, E.; and ROGENT, J., Pantocràtor de Ripoll. La portada romànica del monestir de Santa Maria. Ripoll: Patronat del Monestir de Santa Maria de Ripoll, Ajuntament de la Comtal Vila de Ripoll, Centre d’Estudis Comarcals del Ripollès, 2009, p. 844.

LORÉS, I., “La decoración escultórica en el monasterio de Santa María de Ripoll”, in GARCÍA , J.A.; TEJA , R. (coord.), Los grandes monasterios benedictinos hispanos de época románica (1050–1200), Aguilar de Campo: Fundació S. M. la Real, 2007, p. 176.

PORTA , E. and ARTIGAU, M., Estudi de conservació de la Portada de Ripoll, Sant Cugat: Servei de Restauració de Béns Mobles (SRBM), 2002.

ROVIRA , P., Proposta de Pla Director per a la conservació de la Portalada de Ripoll, SSTT Cultura Girona-CRBMC, 2008.

ROVIRA , P., “Història de la conservació i la restauració de la portalada de Ripoll”, in SUREDA, M. (cur.), La portalada de Ripoll. Creació, conservació i recuperació, Viella, Rome, 2018 (pp. 141–163).

VENDRELL, M.; GIRÁLDEZ, P., Santa Maria de Ripoll. Pàtines, pintures i creixement de guix: estudi de diverses mostres, Barcelona: Patrimoni 2.0, 2016.

VENDRELL, M.; GARCIA , M., Portada Romànica de Ripoll. Estat de conservació i mecanismes de degradació. Barcelona: Patrimoni-UB, 1992.

VENDRELL, M.; GIRÁLDEZ, P.; LLUVERAS, A.; TORRENTS, A., La portada Romànica de Santa Maria de Ripoll. Antecedents històrics i analítics, estat de conservació, assaig de neteja, suggeriments de restauració, propostes de futur, Barcelona: Patrimoni UB. Recerca aplicada al Patrimoni Històric, Universitat de Barcelona, 2004.

VENDRELL, M.; GIRALDEZ, P., Anàlisi qualitativa de la capacitat de filtrat de la radiació ultraviolada dels vidres del nàrtex de la portada de Santa Maria de Ripoll, Barcelona: Patrimoni-UB, Universitat de Barcelona, 2008.

VENDRELL, M.; GIRÁLDEZ, p.; MERINO, L.; BOULARAND, S.; SENOUCI, S.; VADILLO, A., Santa Maria de Ripoll, Portada. Estudi dels materials de formació, acabat i decoració, estat de conservació, intervencions antigues i suggeriments de conservació, Barcelona: Patrimoni 2.0, 2012.

GOLDSCHMIDT, W., “Toulouse i Ripoll. L’origen de l’estil Gilabertus”, in The Burlington Magazine, no. 432, March 1939, vol. 74, pp. 104–105, 108–111 and 114).

CABRERA GARRIDO, J. M., Informes y Trabajos del Instituto de Conservación y Restauración de Obras de Arte, Arqueología y Etnología. La conservación de la portada de Santa María de Ripoll, no. 5, Valencia: Instituto de Conservación y Restauración de Obras de Arte, Arqueología y Etnología, 1965.

CAMPS, J.,“Toulouse, Gilabertus i el seu reflex en l’escultura romànica a Catalunya”, in Quaderns del MEV, vol. 3, 2009, pp.

33–34.

CAMPS, J., “L’escultura romànica en pedra i fusta”, in PÉREZ GONZÁLEZ, J.M., Enciclopèdia del Romànic a Catalunya, Barcelona: Fundació S. M. la Real, MNAC, 2014, p. 124.

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CONSERVATION–RESTORATION

POLYCHROME SCULPTURE

Restoration of four polychrome Neoclassical reliefs from Can Boles (Amer, Selva)

THE FOUR LOW RELIEFS, in a neoclassical style, were in the old building of Can Boles, a large house built where the Abbot’s Palace and part of the cloister of the monastery of Santa Maria d’Amer had previously stood.

Introduction The four panels date from the early eighteenth century. They were possibly installed between 1813–1835, when the abbot Jaume de Llanza i de Valls reformed the choir of the monastery and the chapel of the abbot in the town.

Each one represents a biblical scene carved in low relief: Melchizedek blesses Abraham, the Sacrifice of Isaac, Jael executes Sisera, and Judith kills Holofernes. Each one shows the whole

scene featuring the main characters carved in relief, reinforced with a patina applied here and there. The four panels are accompanied by frames gilded with fine gold, with different mouldings.

State of conservation During their recovery the structural conservation was found to be stable, despite the presence of cracks, damp spots, large dust deposits and signs of damage from xylophagous insects.

Previous restoration attempts of the polychrome were evident, with the entire surface showing signs of having been crudely repainted, as could be seen from the remains of paintbrush hairs and blobs of paint, as well as drip stains.

As a result of this examination a stratigraphic

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Relief with the representation of Melchizedek’s blessing of Abraham before restoration

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Relief with the representation of The Sacrifice of Isaac before restoration

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Relief with the representation of The Murder of Sisera by Jael before restoration

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Relief with the representation of The Death of Holofernes at the hands of Judith before restoration

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Laia Duran, conservator-restorer of painting and sculpture on wood

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Stratigraphy using ultraviolet light at 500X of a sample extracted from the relief of Melchizedek’s blessing of Abraham

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Cross section of sample of alba wood from the frames (Populus, sp.)

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analysis was carried out on the superimposed pictorial strata to distinguish between the repainted layers and the original pictorial layer, so as to be able to then clean the works and recover their original appearance.

The analyses carried out in the CRBMC’s physicochemical laboratory revealed the following layers: 1. surface layer: wax 2. repainted layer: barium sulphate and white lead + synthetic resin 3. original polychrome: white lead with protein + natural resin on the surface 4. Original preparation layer: animal plaster + glue (CaSO4 + 2H2O) 5. base: hardwood: alba (Populus, sp.)

The conservation-restoration process After disinsection in CRBMC’s anoxic chamber and dry cleaning by vacuuming the accumulated dust, tests were carried out to determine the quality of the underlying layers, following the CRBMC cleaning protocol. This was done initially using aqueous-based preparations and then with solvents, where necessary.

First, a thin layer of wax was detected and eliminated by applying isooctane and heat in some areas. A repainted layer made of a very thick synthetic plastic paint was then discovered underneath, in which paintbrush hairs stuck to the paint were clearly visible.

According to the analyses, the repainted layer was made of barium sulphate and white lead, and therefore quite recently added. After removing it with an IE8 gel, the original layer, of a much higher quality, was exposed. This layer was made up of glue tempera imitating marbling.

Between both layers, however, there was another darker coloured, very thin, natural resin.

Certain areas contained drip stains which were removed with an aqueous solution with a strong chelator, gelled with Vanzan® NF-C.

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Relief with the representation of The Sacrifice of Isaac during the process of eliminating repainted layers

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During the final presentation phase, a paste made of wood pulp was applied to the holes created by xylophagous insects, and some areas where material was missing were retouched in order to make the whole work uniform. This was done with water paints after first varnishing the piece.

This was also done with the frames, which showed a high degree of wear in the gilded parts.

These were reintegrated with natural powder of mica mixed with retouching varnish, after first plastering over gaps with traditional putty.

Then, a final varnish layer was applied, in order to unify the whole piece and protect the chromatic reintegration work.

Finally, and as a preventive conservation measure, the backs of the reliefs were covered with a synthetic neutral pH cloth, to protect the nonvisible part during the exhibition of the pieces. The reliefs were provided with frames with screws to facilitate the exhibition of the pieces and distribute their weight equally.

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During the restoration of the reliefs at the CRBMC workshop

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Relief with the representation of The Death of Holofernes at the hands of Judith after restoration

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DETAILS GENERIC CLASSIFICATION: sculpture on wood | OBJECT: 4 panels. Low reliefs carved and polychromed, with golden frames MATERIAL/TECHNIQUE: tempera gold paint | DESCRIPTION: representation of biblical scenes: The Sacrifice of Isaac, Melchizedek’s blessing of Abraham, The Murder of Sisera by Jael, and The Death of Holofernes at the hands of Judith AUTHOR: unknown | DATE/PERIOD: late eighteenth century – early nineteenth century | DIMENSIONS: 131 × 171 × 10 cm c/u | LOCATION: Can Boles building, Amer (Selva) | ORIGIN: Can Boles building, Amer (Selva) | OWNER: Amer Town Council (Selva) | CRBMC REGISTER NO.: 13260 | INVENTORY NO.: 3 of them have municipal property inventory numbers: 000644, 000646 and 000647 | COORDINATION: Pep Paret | RESTORATION: Laia Duran, with the help of CRBMC interns specializing in Painting and Sculpture on wood: Olga Íñigo, Núria Jutglar, Trini Linares and Guillem Masalles. Volumetric and chromatic reintegration work on the frames was carried out by the following students: Marta Carbonell, Xènia Cuberes and Clara Masana | YEAR OF RESTORATION: 2017-2018

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Relief with the representation of Melchizedek’s blessing of Abraham after restoration

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Relief with the representation of The Murder of Sisera by Jael after restoration

Back of the relief with the representation of The Sacrifice of Isaac before restoration

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Relief with the representation of The Sacrifice of Isaac after restoration

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Back of the relief with the representation of The Sacrifice of Isaac after restoration, and with the synthetic cloth attached as a protective measure

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NEWS

Nanorestart Final Conference in Denmark An international conference under the title "Nanomaterials for the restoration of works of art" was held on the 29th and 30th of November 2018 at the National Museum of Denmark in Copenhagen, marking the culmination and closure of the Nanorestart project (www.nanorestart. eu). The various institutions, companies and professionals that have been involved in the project were present to report on the results and announce the lines of future research.

The conference was inaugurated by the mastermind of Nanorestart, Dr Piero Baglioni, from the University of Florence, and it showcased the various products developed during the project by researchers and professionals who have created and tested them on real works. Other notable speakers at the conference included Bronwyn Ormsby (Tate Museum, London), Antonio Mirabile (freelancer) and Marta Oriola (University of Barcelona).

The overall aim of the European-funded initiative was to synthesize new materials using nanotechnology for the conservation and restoration of a wide range of artistic

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materials, especially applied to modern and contemporary works. There were four main lines of research: - Cleaning of contemporary painted and plastic surfaces - Stabilization of canvases and paintings in contemporary art - Removal of unwanted modern materials - Enhanced protection of artworks in museums and outdoors These lines of research and development carried out as part of the Nanorestart project have already produced tangible results in the form of commercial products for use in conservation-restoration, including nano-lime, various formulations of microemulsions and new chemical gels. New products for the inhibition and protection of metals and for the reinforcement of canvases, among others, are also in the pipeline.

Aleix BarberĂ , conservator-restorer of cultural assets

A MUST-READ

La conservation des peintures modernes et contemporaines Alain Roche.

París: CNRS Editions, 2016, 284 p

Contemporary art, especially paintings, continue to present challenges for conservators-restorers to this day, despite the scientific advances and research that has been carried out since the discipline was born in response to the premature and characteristic deterioration of these sorts of works.

In this publication, Alain Roche—in conjunction with his team at the LARCROA laboratory—offers new hope for the preventive conservation of contemporary paintings, demonstrating how their material life can be extended.

The book is divided into three parts, in which the author presents a detailed study of the physical and mechanical properties of the constituent elements of the main types of work that fall under the category of contemporary painting—oil, tempera, wax and acrylics—on canvas or paper.

By doing so, the author hopes to understand the source of the changes that lead to the degradation of these sorts of works, based on their interaction with their environment, be it temporary or permanent.

In this way, he has been able to demonstrate how paintings age mechanically, a tool that enables conservators to know what preventive measures to take and how to intervene.

To obtain this information, the team has used different tools: humidity and temperature sensitivity charts, the minimal variation of tension value and a polynomial function to show a correlation between the previous two.

In short, the author suggests the correct way of preserving these types of works, focusing on the climatic conditions of the space in which they are located. However, as he himself accepts, this calculation isn’t always possible, so he proposes a series of effective alternatives that are more accessible and viable.

As the above suggests, the book contains a great deal of knowledge about physics and mechanics—typical of this author's publications—, so it is really aimed at experts specializing in the conservation and restoration of easel paintings.

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Basic Condition Reporting.

A Handbook Deborah Rose Van Horn, Heather Culligan and Corinne Midgett (Ed.) London: Rowman & Littlefield, 2015, 134 p.

This short book provides the reader with a general idea of the concepts that must be taken into account when assessing the state of conservation of an object.

A useful introduction to the idea of conditions, this handbook is published by the Southeastern Registrars Association (SERA) as a guide so that American museums can work using common terminology and methods.

The need to unify criteria and methodologies is present in all countries, and this document is proof of this. In this sense, any initiative in this regard is to be commended.

The book introduces the reader to the objectives of a good condition report, the methodology used to examine an object and the use of a common vocabulary to document its state of conservation.

The authors structure the conditions based on the materials and the typology of the objects, and generate sample forms for 14 categories; within each there is a glossary of terms and instructions on what should appear in the report and how.

In summary, the book could be improved but it is useful as a reference document. Not everything can be extrapolated to our environment, and when translating and looking for the equivalent term in our language, some of the problems that the authors have attempted to solve appear again.

Maria José Gracia, conservator of cultural artefacts

Daniel Morales, conservator-restorer of cultural artefacts

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CRBMC. CENTRE DE RESTAURACIÓ DE BÉNS MOBLES DE CATALUNYA C. Arnau Cadell, 30 – 08197 Valldoreix Tel. 935 902 970 – Fax 935 902 971 crbmc.cultura@gencat.cat www.centrederestauracio.gencat.cat www.facebook.com/RestauraCat www.instagram.com/restaura.cat

PUBLISHER Departament de Cultura de la Generalitat de Catalunya EDITOR Àngels Solé EDITORIAL BOARD Esther Gual, Josep Paret, Àngels Planell, Pere Rovira,

Mònica Salas, Àngels Solé and Maite Toneu GENERAL COORDINATION Àngels Planell TEXTS © The autors TRANSLATION Sounds & Words PHOTOGRAPHS Ramon Maroto (CRBMC) and the photographers DOCUMENTATION Maria Ferreiro, Àngels Planell and Mònica Salas LABORATORY OF PHYSICAL-CHEMICAL ANALYSIS AND EXAMINATION PHOTOGRAPHS

Ricardo Suárez X-RAY LABORATORY Esther Gual GRAPHIC DESIGN ciklic COVER Ultraviolet photograph of the Santa Maria de Ripoll portal.

Photo: CRBMC, 2016 LEGAL NUMBER B-13.856-2012 ISSN NUMBER (ELECTRONIC PUBLICATION) 2013-3251

Títol Clau: Rescat (Barcelona, Internet) Títol abreviat: Rescat (Barc., Internet)

Generalitat de Catalunya Departament de Cultura