Butlletí <<Rescat>> núm. 32 del Centre de Restauració de Béns Mobles de Catalunya_English by Direcció General del Patrimoni Cultural

Winter 2017

INTERVIEW

M. Àngels Jorba Valls Page 3

CONSERVATION RESTORATION

The Roman Mosaic of the Sacrifice of Iphigenia Page 8

Removing tide lines in books whithout dismantling or unbinding Page 13

Intervention on the main façade and the monumental entrance to the Monastery of St Peter of Galligants Page 16

The doors of the Madonna of the Rose Bush altarpiece from St Felix of Cartellà church Page 24

A pietà from the Diocesan Museum of Tarragona attributed to Antoni Viladomat Page 30

INNOVATION AND RESEARCH

Steps towards a system of volumetric reintegration by 3d-printing of ligneous supports Page 36

PLUS ...

News and Books

CONSERVATION AND RESTORATION

THE SACRIFICE OF IPHIGENIA

Centre de Restauració de Béns Mobles de Catalunya

INTERVIEW

EDITORIAL

M. Nieves Marí Ribas, conservator-restorer of archaeological materials

M. ÀNGELS JORBA VALLS Conservator-restorer of archaeological and ethnological materials at the Centre for the Restoration of Movable Property of Catalonia (CRBMC, for its initials in Catalan), where she has worked since 1981.

IT WAS ARAGON THAT DIDN’T CONSERVE THE SIXENA WORKS The president of the Aragonese government, Javier Lambán, complained last December about the state of conservation of the Sixena works from Lleida Museum. I don’t know whether his statements revealed ignorance or just self-assured cynicism. Mr Lambán should know that when the convent was burnt down by anarchists in 1936 the Sixena works suffered serious damage, as is perfectly documented. The works remained in the convent for decades, during which time they became increasingly deteriorated without the Aragonese administration showing any concern for their restoration. In 1970, once the nuns had moved to Valldoreix and the works had been acquired by the Catalan government, they arrived in Lleida Museum in a pitiable state. Some of them would be restored

and others would be installed in the museum’s reserve, where favourable conditions of preventive conservation counteracted the degradation, before further resources were made available for the restoration to proceed. Who holds responsibility for the state of conservation of the works, therefore, is clear. The president of Aragon shot himself in the foot. On the other hand, it would be interesting to establish the condition of the works in the Aragonese reserves, as museums do not usually have sufficient economic resources to restore all the works in their collections and therefore have to restore them to the best of their ability. The Aragonese government should have ensured that the works moved to Sixena would be preventively conserved under the right conditions. We have no knowledge of these conditions. The reports drawn up by Lleida Museum and the Centre for the Restoration of Movable Property of Catalonia (CRBMC) warned the Aragonese authorities of the risks entailed by moving the works without a previous restoration. They were also alerted as to the necessary requirements of the vehicles supposed to transport them. In spite of all the advice, the plundering took place under the worst possible conditions. Àngels Solé. Director of CRBMC

Sarcophagus of D. Beatriu Cornel, 15th century, from the convent of Sixena, before and after the restoration carried out by CRBMC Photo CRBMC: Carles Aymerich

RESCAT

THE CAREER OF A HISTORIAN AND RESTORER OF ARCHAEOLOGICAL MATERIAL IN THE EARLY DAYS OF CRBMC Starting from her relationship with the team of archaeologists headed by Dr Maluquer de Motes, M. Àngels Jorba Valls was involved in excavations in Catalonia and abroad, in sites of different ages, where she discovered the needs of archaeological excavations and the role played by the restorer in the team when it comes to handling and treating materials correctly

M. Àngels Jorba Valls was born in Rubí in 1953, and began her academic studies at the Geography and History College of the University of Barcelona. Two years after graduating and specialising in Ancient History (1976) she moved to Madrid, where she obtained a diploma in Applied Arts and Restoration and specialised in Archaeology (1981). Having completed her studies, she worked at the archaeological laboratory at the Institute of Archaeology and Prehistory of the University of Barcelona until 1989, when she joined the first team of restorers at the repository of archaeological material at the Centre for Conservation and Restoration (the current CRBMC). Where does this interest in archaeology stem from? What led you to the restoration of archaeological material? I’ve always been interested in historical subjects. I knew from very early on that I wanted to go to Madrid to study restoration, but in those days – 1971 – it wasn’t easy, so I studied Ancient History at the University of Barcelona. During those years I joined forces with archaeologists working with Dr Maluquer de Motes, which enabled me to take part in excavating campaigns in Catalonia and abroad. I worked with a variety of materials and in sites from different periods, with very different teams and ways of working, both in the laboratory and in situ. The experience taught me to see the shortages and needs within an archaeological excavation, and the role www.centrederestauracio.gencat.cat

played by the restorer in the team, handling and treating the materials which will be scientifically studied and appropriately placed in the historical ensemble. Dr Maluquer and I agreed that the figure of the restorer was indispensible in the world of archaeology, and he encouraged me to further my studies in the speciality of Archaeological Restoration in Madrid, the only city in Spain that had a school of restoration arts. In the capital, I was able to carry out practical studies at the

“RESTORERS WERE HANDYMEN WHO ENSURED PIECES WERE HELD TOGETHER AND COMPLETED, IN SOME CASES PUTTING THEIR IMAGINATION TO THE TEST.” Institute for the Conservation and Restoration of Artworks and at the National Museum of Archaeology. Do you remember your first job as a restorer? Once I had completed my studies I returned to Barcelona, where I was hired by the Institute of Archaeology of the Central University [and worked] under the supervision of my mentor, Dr Maluquer de Motes. My first assignment was to restore the mateRESCAT

Centre de Restauració de Béns Mobles de Catalunya

The spacious building houses the facilities and tools needed to perform meticulous scientific restorations, with temperature and humidity control. We also have a physical-chemical laboratory that cannot always examine all our inorganic materials, and an X-ray machine, powerful enough to analyse metals and ceramics. The centre’s first organisation chart was drawn up in 1989, establishing the first positions. I was in charge of the speciality of Archaeology and Ethnology, but didn’t have a permanent team. We welcomed trainees and interns from the Fine Arts College and later on from the Higher School of Conservation and Restoration of Cultural Assets of Catalonia (ESCRBCC, for its Catalan initials), as well as independent restorers. The work was very routine and entailed little research, although it gradually began to change and the students were increasingly informed when they arrived.

Visit to the Diocesan and Regional Museum of Solsona, before work began on the new museum, around 1982-1983. Unknown photographer

rials from the excavations carried out by the professors, chiefly ceramics and furnishings, bones and weapons from the Iberian necropolis of Mianes in Santa Bàrbara (Amposta), and was quite complex. Our mission consisted in completely restoring all the pieces, and then photographing and drawing them for the corresponding publication. How did you join the team at the Centre for Conservation and Restoration? Early in 1982 I met Sr Jaume Mayas, restorer at the Archaeological Museum of Catalonia (MAC, for its Catalan initials) and member of the former Technical Group. We had been introduced by Josep M. Xarriè, who at the time was setting up the Centre for Restoration by orders of the Catalan government. Let’s say I was in the right place at the right time. In those days the Centre for Conservation and Restoration already offered several specialities including Mural Painting, Painting on Canvas and Altarpieces, though not yet Archaeology, so Josep M. Xarrié asked Núria Flos (currently a teacher of Conservation– Restoration of Archaeological Material at the University of Barcelona, UB) and me to set up a new workroom for the restoration of archaeological material. At first it was a bit precarious and I was only working part-time, which was compatible with my contract at UB. RESCAT

Conservation and restoration tasks carried out on the premises of the Diocesan and Regional Museum of Solsona, around 1982-1983. Unknown photographer In-situ intervention in the Roman town of Els Munts (Altafulla). Lifting of the mosaic with the figure of the muse Mnemosyne, 1996

How was archaeological restoration carried out in Catalonia when you joined the Centre for Conservation and Restoration? The Cultural Heritage Board encompassed both the Museum Service and the Archaeology Service. In the beginning, restoration was a service offered to museums, but the speciality of archaeology fell upon the Archaeology Service. Our work at the centre came from excavations and museums. Indeed, the excavations were supervised by museums and universities. Initially, the conservators were in charge of conducting the scientific and historical studies, so the most important objects had to be restored – ceramics, mosaics, glassware – and the display cases had to be filled. Restorers were Cleaning of the plaster handymen who ensured covering a skeleton from the Bronze Age in the Episcopalian pieces were held toMuseum in Vic, 2001-2002 gether and completed,

Cleaning and partial reintegration of a piece of Iberian pottery from the Diocesan and Region Museum of Lleida, 2006. Photo: Jordi Play

in some cases putting their imagination to the test. When I arrived at the centre I introduced new criteria, based on my studies, my experience and [knowledge obtained from] the places I had visited. These criteria gradually converged with international guidelines that included minimum intervention, reversibility of materials, etc. Does the centre still collaborate with museums and excavations? From the very beginning we have worked in close collaboration with a number of museums. The Diocesan and Regional Museum in Solsona was the first, followed by the Museum of the Terres de l’Ebre Cleaning of the menhir from Mollet, in Amposta, the Episcopalian 2009 Museum in Vic, the Diocesan and

What were the facilities at the Centre for Conservation and Restoration like, and how was the Archaeology section organised? The origins of the Centre for Conservation and Restoration, that subsequently became the Service [for Conservation and Restoration], were humble. It opened in premises in the cloister of the Monastery of Sant Cugat del Vallès, lacking in climate control and yet large enough to accommodate easels, tables, chairs, lamps and even a photographic studio. From 1981 onwards the centre would grow steadily, and in 2003 we moved to the new building in Valldoreix, which is more functional and adapted to the works of restoration. www.centrederestauracio.gencat.cat

RESCAT

Centre de Restauració de Béns Mobles de Catalunya

Extraction in situ of the chrismal mosaic from Prats de Rei (Anoia) with David Jimeno, 2013

Packing of the processional cross with the pietà motif from the Seu d’Urgell, after the intervention by M. Àngels Jorba and metalsmith Montserrat Cañís, 2017

Installation of the loom in the Ethnographic Museum of Ripoll, 2011

Dismantling of the bust of St Peter, orfèvrerie from the Priory of Reus, 2013

after the process of conservation and restoration, how they stood out in their new exhibition setting was very satisfactory. Which of your restoration projects was more complicated? The most difficult project was no doubt the uncovering and moving of a sepulchral headstone with serious conservation problems and a deficient preparation. This made the restoration a long-drawn-out process.

Regional Museum in Lleida, Granollers Museum, the National Archaeological Museum in Tarragona, Arenys de Mar Museum, the Museum of Archaeology of Catalonia-Empúries, etc. We also work on excavations, unearthing archaeological elements such as mosaics or urns. The more complete an artefact is when it is uncovered, the more accurately it can be restored in the laboratory. This is why I’ve always insisted on the need to have restorers working within excavation teams.

As well as working as a restorer you’ve also been a teacher to many apprentices and interns, both from the Higher School of Conservation and Restoration of Cultural Assets of Catalonia (ESCRBCC). What do you think of the training received by future restorers

of archaeological remains? Would you like to send a message out to the restorers of archaeological material you have taught? People always say that restoration studies are long, never-ending in fact. Artefacts arrive in varying states of conservation, and the treatments must meet their specific needs. Nowadays, students are well versed in theory, which is a good thing, but they have to confront ancient objects. Broadly speaking, what I’d like to pass on to them is calmness. I’d like to tell them that group work is always very important, just as important as it is for them to ask themselves questions (regarding the treatments, the problems that emerge, the finishes, etc.) and to come up with answers between the members of the group. We must never be afraid of a piece, but trust that our knowledge will enable us to understand it and know how to deal with it. Now that you’ll be retiring next year, do you think you’ll miss the actual work, or any other aspect of your profession? I think I’ll miss the routine, the problems posed by certain artefacts, and the colleagues with whom I’ve worked and shared good moments. But time goes on, and we must make way for new restorers. The last multidisciplinary team of archaeological restorers to have worked with M. Àngels Jorba, November 2017

The world of archaeological restoration covers a wide range of materials. Have you specialised at all? Do you consider it necessary to specialise in specific materials within the field of archaeological restoration? Archaeological restoration encompasses a hotchpotch of materials, and therefore of specialities. While it’s a

“I HAVE ALWAYS FELT ESPECIALLY DRAWN TO METALS.” good idea to get to know them all, time and experience eventually lead us to specialise. An organisation like ours welcomes all sorts of materials, all of which must be able to be restored. Specialisation should be necessary but not exclusive; having broad-ranging knowledge makes our work easier. In my case, despite having worked with all kinds of materials, I have always felt especially drawn to metals, as reflected in my undergraduate thesis Tratamiento y aplicación de los métodos de conservación y restauración en materiales metálicos (Universitat de Barcelona, 1983). RESCAT

What materials do you consider more vulnerable? All the materials unearthed in a digging are vulnerable. The change of environment temperature and relative humidity are crucial for their conservation. The sooner we act, the lesser the risk. Which assignment have you enjoyed the most? Besides the deposit of Bor bronzes, a fortuitous discovery I have been working on for the past few months, my most rewarding assignment was the restoration of pieces from the Ethnographic Museum in Ripoll, on account of the variety of artefacts and materials (field tools, mannequins, door knockers, bridal boxes, votive horseshoes, a loom, etc.). Seeing the pieces change www.centrederestauracio.gencat.cat

RESCAT

CONSERVATION-RESTAURATION

Centre de Restauració de Béns Mobles de Catalunya

INTERVENTION IN ARCHAEOLOGICAL MATERIAL

The Roman Mosaic of the Sacrifice of Iphigenia THE MOSAIC OF THE SACRIFICE OF IPHIGENIA is an opus vermiculatum mosaic emblem that represents a small figurative scene of the sacrifice of Iphigenia. Dating back to the first century BC, it has Hellenistic influences and was inspired in mural paintings. At the centre of an opus tessellatum mosaic, it formed the pavement of a room in one of the most lavish Roman houses in the archaeological site of Empúries. Opus vermiculatum mosaics are characterised by the use of minute tesserae laid around figurative motifs to emphasise their outline (the muscles of the characters, the leaves on the trees, etc.) in undulating wormlike rows, as indicated by the name of the technique — vermiculatum, from vermis, worm. In order to express the effect of light and the different volumes, the stones are of multiple shades. The use of such small closely set tesserae is ideal for representing details. The figurative scene depicts an episode from The Iliad in which Artemis, infuriated by the scorn of the Greeks, made sure they were unable to leave the harbour and set out for the Trojan War by ensuring there was no wind. The seer Calchas, dressed in white, prophesised that the only solution was that Agamemnon, King of Mycenae, sacrificed his daughter Iphigenia, who is seen holding the hand of Ulysses, deceiving her by saying she was to marry Achilles. At the last minute, the goddess Artemis – who we see in the upper right-hand corner of the scene – would take pity and replace Iphigenia with a female deer. Other figures in the scene are Menelaus, King of Sparta, holding a sceptre, Achilles, holding a shield; a camillus or servant helping out at sacrificial ceremonies, bearing a tray, a towel and a jar; and five men and a woman who appear behind the main characters. In the foreground we see the sacrificial altar, a torch, the head of an ox adorned with garlands, and a picture of an armless bust and an erect phallus on a stem (ithyphallic herm). In the background we discover two metal sculptures of the gods Apollo and Artemis. Historical information The Iphigenia mosaic was a casual find made in 1848 by a neighbourhood association in L’Escala that had purchased some land from the RESCAT

Carolina Jorcano, conservator-restorer of archaeological material

Photograph taken by Manuel Genovart i Boixet in 1923 showing the loss of stones in several areas of the mosaic and the formation of a lacuna in the lower area. Photo: © Arxiu Fotogràfic Centre Excursionista de Catalunya

Photograph in the visible spectrum and a part of the UV spectrum revealing the volumetric reintegration in shades of green, and therefore the loss of original tesserae. The restored surface, that of all the greenish areas, is clearly a significant part of the ensemble Photograph of the mosaic when it arrived at CRBMC, before the interventions in conservation and restoration

A postcard image of the Iphigenia mosaic. The photograph was taken at the time when the mosaic had two owners, as can be read in the caption. On the one hand, it was public property, as it belonged to the Monuments Commission of Girona, and on the other, it had a private owner. The areas of the mosaic with lost tesserae when the mosaic was still in place are quite visible Source: Museu Arqueològic de Barcelona Photo: Museu d’Arqueologia de Catalunya

X-ray of the mosaic in which we see the metallic mesh of the secondary support made of reinforced concrete. The mesh is in perfect condition and shows no deformation or increase in volume indicative of oxidation and corrosion of the metal

www.centrederestauracio.gencat.cat/

archaeological site. They were digging in search of antiques for the private collections of its members, which was a widespread and accepted practice in those days. The Iphigenia mosaic, however, couldn’t be divided up between the members without being damaged, and so they decided to sell it in order to make a profit. While they were looking for a buyer, they protected the mosaic by erecting a small enclosure that would prevent it from being broken or stolen. In 1879, thirty years later and still no buyer for the mosaic, the Monuments Commission of Girona – whose hands were tied – began to receive complaints concerning its state of conservation. The mosaic was deteriorating rapidly due to the loss of tesserae in areas such as Iphigenia’s neck, for instance. No buyer had yet appeared by 1909. That year the neighbourhood association was reduced to the brothers Francisco and José María Oliveras Maranges, who decided to sell the mosaic for 12.000 pesetas. The advertisement was published in the press on account of the work’s relevance, and a number of museums from around the world – including the Louvre – showed an interest. Thirty years later there was still no buyer for the mosaic, and in 1879 the Monuments Commission of Girona, – whose hands were tied– began to receive complaints concerning its state of conservation. The mosaic was deteriorating rapidly due to the loss of tesserae in areas such as Iphigenia’s neck, for instance. No buyer had yet appeared by 1909. That year the neighbourhood association was reduced to the brothers Francisco and José María Oliveras Maranges, who decided to sell the mosaic for 12.000 pesetas. The advertisement was published in the press on account of the work’s relevance, and a number of museums from around the world (including the Louvre) showed an interest. In 1914, due to the debts incurred by José María, half of the Iphigenia Mosaic became public property and passed into the hands of the Monuments Commission of Girona, while the other half was still owned by Francisco. From that point on, the mosaic could be visited. At the onset of the Spanish Civil War, Republican militias settled on the archaeological site. In view of the danger that the mosaic might deteriorate or lose some of its pieces, the then Minister of Justice, Bosch Gimpera, ordered it be lifted out of the ground. Transported to the Archaeological Museum in Barcelona, four years later, in 1940, it was restored by Adolfo Maragliano Pagès and the Spanish state became sole proprietor. Finally, in 1956 it was moved to Empúries. RESCAT

Centre de Restauració de Béns Mobles de Catalunya

Reasons for the intervention, state of conservation and organoleptic examination In 2014, the Archaeological Museum of CataloniaEmpúries chose some of its most important works with the intention of reworking the restorations carried out in the first half of the twentieth century, some of which had been precarious interventions. The restoration of the Iphigenia Mosaic performed by Adolfo Maragliano in 1940 followed the restoration criteria of the period, which consisted in placing a secondary support of reinforced concrete on a metallic mesh attached to the back of the mosaic, the volumetric reintegration of the lacunae with gypsum plaster, and the application of polychromy. The general condition of the mosaic was fairly good, except for the green, black and brown tesserae that were quite deteriorated. This posed the problem of discerning whether these alterations were produced by the salts of the concrete used in the secondary support and/or the possible corrosion of the metallic mesh. A preliminary study was carried out to decide the specific intervention criteria and conservation-restoration processes, and in particular to establish whether to remove the support attached to the back and the volumetric and chromatic reintegration considered historical. The removal of the secondary support implied a very high risk of disaggregation of the whole mosaic because of the small size of the tesserae and because apparently very little of the original mortar had been conserved, indeed in some cases none at all. Preliminary studies In order to draw up an intervention proposal we carried out bibliographic research, used different image diagnosis and analytical techniques, and several tests that produced the following results: RESCAT

Results of the analyses of several samples taken from the superficial layer, and of the polychromy of the volumetric reintegration. µFTIR (Fourier Transform Infrared Spectroscopy) tests show that the topmost layer consists of beeswax

Results of the analyses of several samples taken from the superficial layer, and of the polychromy of the volumetric reintegration. GC/MS (gas chromatography/ mass spectrometry) tests reveal that the binder used was linseed oil

The historical photographs of the mosaic, together with those taken under UV light clearly reveal which parts of the mosaic are original and which are reintegrations, the latter being a significant percentage of the mosaic ensemble. The X-ray shows us that the metallic mesh of the secondary support of the mosaic, made of reinforced concrete, is in perfect condition. It shows no signs of corrosion or volumetric deformation that could produce mechanical tensions leading to cracks and fractures in the mosaic. The results of analyses with µF-TIR techniques and gas chromatography, made from samples taken from the surface of the mosaic, establish that the pictorial technique used to colour the volumetric reintegration is oil paint, and that the protective coating of the mosaic surface is wax.

Results of the analyses of several samples taken from the superficial layer, and of the polychromy of the volumetric reintegration. The graph shows that the technique used to add the polychromy to the gypsum after the repair and reintegration was oil

Removal of the wax and cleaning of the superficial dirt superficial with an oil-inwater emulsion, controlling the pH and conductivity measured on the surface. Photo: Carolina Jorcano

Removal of the volumetric reintegration of part of the edge concealing the original tesserae, that are sunken. Photo: Carolina Jorcano

Volumetric reintegration of lacunae with lime mortar, and reintegration of the tesserae with gypsum plaster. Photo: Carolina Jorcano

Arbocel 200 natural cellulose fibre poultices with deionised water to measure conductivity before and after application, in order to detect the presence of soluble salts on the support Photo: Carolina Jorcano

Application of an agarose tablet to the different surfaces of the mosaic (stone and polychromy) to discover their conductivity and pH, and to obtain an effective cleaning system. Photo: Carolina Jorcano

Detail of an area of the mosaic before the process of conservation and restoration and after the chromatic reintegration

www.centrederestauracio.gencat.cat/

RESCAT

Centre de Restauració de Béns Mobles de Catalunya

Final photograph after the interventions in conservation and restoration

The salts test recorded negative results for the presence of soluble salts on the surface of the mosaic. We ruled out the possibility that the aforementioned deterioration of the tesserae was caused by soluble salts in the concrete. The decision we reached after concluding all the tests was not to remove the secondary support, in view of its good condition and of the fact that it didn’t affect the state of conservation of the tesserae, not to mention the risk involved in its dismantling. Along the same lines we decided not to remove either the volumetric or chromatic reintegration, on account of the large surface they occupied in the mosaic ensemble and of the loss of information concerning the figurative scene that the removal would entail.

Process of conservation–restoration The conservation-restoration intervention consisted in cleaning the surface of the mosaic with a system measuring the conductivity of the surface and its pH, that would enable us to remove the protective layer made of beeswax, and the grime and dust deposited on it, without eliminating the paint of the volumetric reintegration. After having carried out several tests with different products and bearing in mind that the cleaning should not affect the oil paint of the reintegration, what worked best was an oil-inwater (O/W) emulsion without surfactant, with a buffer solution of pH 7.0 and 1000 µs, 2% of Vanzan gel and 10% of isooctane. The earthy and calcareous concretions on some of the tesserae were mechanically removed. Those volumetric reintegrations that were thicker than the original tesserae – and therefore protruded from the surface of the mosaic and occasionally even covered original tesserae that had sunk or had been partly destroyed due to erosion of the upper layer – were either reduced or eliminated. Finally, we removed the reintegration of gypsum plaster in the two lacunae at the lower corners of the mosaic to reveal the remains of original mortar, and replaced them with calcium mortar, restoring the volumetric reintegration of the tesserae with their original material, i.e., gypsum plaster. The stones were bevelled with mortar to avoid the risk of detachment, and then a protective layer of 3% concentration of Paraloid B-72 resin was applied to ensure the brightness was uniform and the shine of the original tesserae matched that of previous interventions. The last step was the chromatic reintegration. Lastly, the stone base was mechanically cleaned and washed to remove the remains of adhered sediment particles, after which the loose fragments of frame were fixed with a high concentration of Paraloid B-72. The lacunae were reintegrated with traditional calcium mortar to strengthen the spots that seemed fragile and were in danger of becoming detached in order to ensure the delicate area of the base was solid.

GENERIC CLASSIFICATION: Archaeological material | OBJECT: Opus vermiculatum mosaic emblem and stone base that acts as a frame | MATERIAL / TECHNIQUE: Stone | TITLE: Sacrifice of Iphigenia | DATE / PERIOD: I BC DIMENSIONS: mosaic: 56.6 x 59.8 cm; stone base: 64.1 x 61 cm | LOCATION: Museu d’Arqueologia de Catalunya, Empúries (Alt Empordà) | PROVENANCE: Graeco-Roman archaeological site of Empúries (Alt Empordà) CRBMC REGISTRATION No.: 12297 | INVENTORY No.: MAC-Empúries 2552 | COORDINATION: M. Àngels Jorba RESTORATION: Carolina Jorcano | YEAR OF THE RESTORATION: 2017

RESCAT

Clara Bailach and Magalí Gómez–Franco, conservators and restorers of archive graphic material

INTERVENTIONS IN ARCHIVE MATERIAL

Removing tide lines in books without dismantling or unbinding. A case study THIS ARTICLE SHOWS THE DIFFICULTY of eliminating tide lines in bound books, and reveals the process followed to attain this objective, preserving the integrity of the binding and of the sustained elements. Introduction A group of thirty-seven medium-sized illustrated books from the Museu d’Arqueologia de Catalunya has been treated. The volumes had large moisture stains that could be appreciated on almost all the pages. Aureoles due to humidity pose aesthetic and conservation problems for paper supports and for the correct reading of sustained elements, whether they be texts or pictures. Moisture is needed to remove them, as it enables the material deposited on the support to be solubilised again. In the case of books, it is difficult to provide the support with sufficient moisture without dismantling the binding, following the principle of minimum intervention. Our methodology is based on capillary action, although it includes new materials that emerged from the courses in Oriental bookbinding techniques applied to the restoration of paper recently made public by Luis Crespo (conservator and restorer of cellulosic supports at the National Library of Spain), from the courses imparted at the Polytechnic University of Valencia (UPV, for its initials in Catalan), and at the Centre for the Restoration of Movable Property of Catalonia (CRBMC, for its initials in Catalan) during 2015 and 2016.

Detail of a page in one of the volumes before treating Photo: Clara Bailach

After the treatment Photo: Clara Bailach

Objectives of the intervention Besides the various pathologies, such as curved or cockled supports, the chief visible alteration of documents were pronounced stains and tide lines derived from direct contact with moisture, present in all the volumes and on most of the pages. These stains hindered the reading of the text and the illustrations. Furthermore, the deposited material entailed a risk in itself, because www.centrederestauracio.gencat.cat/

RESCAT

Centre de Restauració de Béns Mobles de Catalunya

Optimised removal of aureoles due to humidity using new materials and following the method specifically designed for this ensemble. Foto: Clara Bailach

if the stain had become permanent, in the long run it would have accelerated the deterioration of the paper in the area in question. The intervention was intended to remove and minimise the stains in order to stabilise the support, restore the aesthetic uniformity of each page and enable the correct reading of the documents. Limitations of the treatment The application methodology posed two difficulties.

1. The application of moisture. As we were dealing with paper that hadn’t previously undergone any aqueous cleaning process, the application of moisture with a paintbrush could have generated new stains around the treated area.

The two previously described limitations are surmounted by introducing new materials we shall now describe. 1. The application of moisture with a mizubake, a mini Japanese brush. A handmade Japanese water brush with deer hair bristles and a wooden handle sewn on with thread with no metal part. This kind of brush has a good water retention ability and enables moisture to be applied in a controlled fashion. The water spreads gradually through the paper without generating new aureoles.

2. Control of dimensional stability. It is important to control the risk of creating new deformation.

2. The absorption of residues with Sontara Heavy. A mixed laminated material made up of cellulose pulp and polyester, with a great power of absorption and resistance, easy to reuse, thin, flexible and highly adaptable to the surface it comes into contact with.

Application of new materials to optimise the treatment

Process of conservation and restoration After carrying out the various physical and

GENERIC CLASSIFICATION: Archive material | OBJECT: Books | MATERIAL / TECHNIQUE: Cotton paper, printed ink and printed illustrations | DESCRIPTION: Representations of themes taken from classical culture accompanied by an explanatory text | DATE / PERIOD: Seventeenth and eighteenth centuries | DIMENSIONS: Varied LOCALITION: Museu d’Arqueologia de Catalunya, Barcelona (Barcelona) | CRBMC REGISTRATION NO.: 12271 COORDINATION: Carme Balliu | RESTORATION: Clara Bailach and Magalí Gómez-Franco | YEAR OF THE RESTORATION: 2016

RESCAT

chemical tests required in all intervention processes, a mechanical cleaning was performed to remove the dust and superficial dirt from the support. Archive material was then vacuumed with a high efficiency particulate air (HEPA) filter and, with the help of brushes, specific deposits found on the support were removed. The prior study of the ink solubility had proved positive on the ink of the stamps found on the lower side margins of most pages. The stamps were protected with pentasiloxane silicon solvent (cyclomethicone D5) that prevented water from coming into contact with the ink. After the treatment, the solvent evaporated leaving no residue. The methodology consisted in opening the book a full 90 degrees, placing a rigid methacrylic or similar base under the page to be treated and protecting the base with a sheet of waterimpermeable material or polyester film (Melinex). We then covered the Melinex with Sontara Heavy, gently applied water to the support with the mini mizubake brush and cleaned the aureole until it disappeared, preventing the appearance of new stains. The Sontara Heavy and Melinex were then removed, blotting paper was placed above and below the treated damp area. Weight and a rigid support were then put in place, and the blotting paper was changed frequently to make sure no curling occurred.

www.centrederestauracio.gencat.cat

Working on several volumes at the same time helped speed up the intervention and alternate the processes of cleaning, drying and changes of blotting paper. Once the support was stable, the tears were consolidated and certain areas of the support were restored. The spines and binding of some of the volumes were also consolidated with Japanese paper of different weight, and a wheat starch adhesive was prepared mixing one part of powder with three parts of water in following the traditional Japanese method. Conclusions The capillary absorption technique and the application of new materials have enabled us to treat these books without having to unbind the volumes, and to perform immersion washing of all the pages affected, after having been previously humidified. This procedure enabled us to eliminate practically all the large tide lines on the documents and restore the stability of the books. We have also managed to preserve the materials and original marks made when the volumes were produced, and the traces left on them by the passage of time that enhance their value. We recommend this process, with the modifications required in each specific case, as a valid option for other interventions intended to preserve the integrity of bindings and restore the correct reading of books.

RESCAT

Centre de Restauració de Béns Mobles de Catalunya

CONSERVATION–RESTORATION

INTERVENTION IN STONE

Calcareous concretions in the form of scales. Photo: Arcovaleno Restauro, SL

Intervention on the main façade and the monumental entrance to the Monastery of St Peter of Galligants THE MONASTERY OF ST PETER OF GALLIGANTS is in the heart of Girona. Owned by the bishopric of the city, at present it is the Girona centre of the Archaeological Museum of Catalonia (MAC-Girona). The conservation-restoration of the main façade that we shall describe in this article is set within a broader conservation programme of the ensemble that also contemplates the renovation of the roofs of the monastery, as a part of the Open Romanesque Programme funded by “la Caixa” Outreach Projects. Arcadi Pla renovation company was the main contractor of the work, and commissioned Arcovaleno Restauro with the conservationrestoration of the main façade. The restoration work was carried out by a team of conservators and restorers specialised in the restoration of stone material between the months of August and November of 2012. Brief historical description The Benedictine monastery of St Peter of Galligants was founded in the first half of the tenth century, outside of the walled precinct of Carolingian Girona, on the other side of the River Galligants. The architectural structure of the monastery in those days is unknown, as the present church and cloister are later constructions that were probably built over the previous structure. We learn from the will drawn up by Ramon Berenguer III, Count of Barcelona, that in the year 1131 the church was under construction. The historical and artistic study carried out by Llorens i Rams, Sant Pere de Galligants. Un monestir al llarg del temps, published by MACGirona in 2011, concludes that the monastery can be generally dated to the twelfth century. The sculpture in the church can be attributed to the first half of the century, whereas the rose window was probably made between the late twelfth and early thirteenth centuries. The monastery would suffer many alterations RESCAT

Kusi Colonna and Rudi Ranesi, conservators–restorers of cultural assets

View of the façade after the intervention (January 2013). Photo: Arcovaleno Restauro, SL

Black crust on the capital and the rose, and under a corbel of the sarcophagus. Photo: Arcovaleno Restauro, SL

www.centrederestauracio.gencat.cat

over the course of time. As regards the façade, we know that three buildings were erected in the eighteenth century, the first of which was annexed to the church and to the cloister: the abbot’s palace, the chamberlain’s house and the sacristan’s house. The enclosure of the monastery, that also included St Nicholas’s church, the cemetery and the vegetable garden, probably originated at the narrowest point of Carrer de Galligants. We have no further information of the façade until the twentieth century, when several modern interventions notably changed the external appearance of the monastery. In 1966 a part of the former abbot’s palace was demolished. The annex ran almost all the way to the monumental entrance to the church. This alteration was integrated in the programme designed to create Girona’s Passeig Arqueològic in the late twentieth century. The refurbishment of the façade continued in 1968 with the adjunction of seven new rows of ashlars above the rose window, altering the original appearance that had gables. In 1981 the rose window was dismantled and restored. Before it was restored to its original position in the façade a replica was made and the copy was displayed in the absidiole of the north arm of the transept of the church. Architectural description The main façade of St Peter of Galligants is made up of two rectangular sections, on two superimposed constructions, and the base is almost double the width of the crown. The plane of the façade, plain and unadorned, is interrupted by four openings: the large rose window in the upper segment, the monumental entrance and two windows in the lower segment. Both the rose window and the doorway can be considered sculptural jewels of the Romanesque. The decoration is concentrated in these areas and presents ornamental elements such as reliefs, friezes and capitals of great historical and artistic interest. The monumental entrance consists of five archivolts that are supported on columns and pilasters. Some of the columns are decorated with helicoidal and vertical flutes. The archivolts display a rich repertoire of plant, geometric motifs and lacelike motifs. The decoration of the capitals and imposts depicts plants, animals, fantastic beasts and human beings. In the rose window, along with further plant motifs such as stems, leaves and pine cones amidst friezes, small columns RESCAT

Centre de Restauració de Béns Mobles de Catalunya

Black crust on the capital and the rose, and under a corbel of the sarcophagus. Photo: Arcovaleno Restauro, SL

with capitals decorated with plant elements, human heads, animals and gryphons, we also discover the representation of an abbot surrounded by monks and an inscription that recalls the authorship of the sculptures: OMNES COGNOSCANT PETRVM FECISSE FENESTRAM — Let everyone know that Peter made this window. Constitutive materials The façade is built of ashlar masonry, the blocks being of Girona stone and lime mortar. From a geological point of view, it is a grey bioclastic limestone with a large number of fossils, made of calcite with a matrix of micritic calcite and a variable percentage of clays and rock fragments formed by calcium carbonate crystals. According to the geological report drawn up by the University of Barcelona,1 the monumental entrance and the rose window were sculpted in a variety of Girona stone that is more homogeneous and even than the other varieties. Access to the rose window allowed us to establish that the two small horizontal columns (shafts and capitals) are made of marble, while the others are of fossiliferous limestone.2 A detailed look at the mortar has enabled us to distinguish three types, two of which seem to be subsequent to the construction of the façade, and the other would be attributable to the initial building stage. The latter is a pinkishorange mortar of fine grain size, apparently of

Loss on a corner. Photo: Arcovaleno Restauro, SL

Patina on the column of the monumental entrance. Photo: Arcovaleno Restauro, SL

Ashlars showing fissures. Photo: Arcovaleno Restauro, SL

State of conservation We shall now list the various factors that determined the state of conservation of the façade. Loss in the shape of a star. Photo: Arcovaleno Restauro, SL

Patina on the rose window. Photo: Arcovaleno Restauro, SL

Màrius Vendrell and Pilar Giráldez, Façana de Sant Pere de Galligants. Materials de construcció, estat de conservació, mecanismes de degradació, suggeriments de restauració. Estudis del patrimoni històric, Patrimoni-Universitat de Barcelona, 2006. 2 Màrius Vendrell, Pilar Giráldez and Andrés Vadillo, Sant Pere de Galligants, Girona. Caracterització de les pàtines i acabats de la façana principal. Estudis del patrimoni històric, PatrimoniUniversitat de Barcelona, 2012. 1

RESCAT

lime and containing crushed brick that seems to grant it its orange colour. Found around the original ashlars, it is sometimes inserted to mark the limit of the ashlar and appears to be the original mortar joint. In the 2012 report, Màrius Vendrell explains that the joints examined are of aerial lime-based mortar characterised by a heterometric aggregate according to their widths: fine sand for fine joints and sand mixed with gravel for wider joints. The study carried out by the University of Barcelona did not distinguish between the different types we have identified. Nonetheless, the authors reported that in many cases the materials studied were repair mortars. On the façade we identified patinas and finishes described in the aforementioned study. As regards the orange-coloured patina, we believe it isn’t original, as we shall discuss later. The cleaning process revealed the presence of black polychromy on the monumental entrance, specifically on the decoration of the archivolt, consisting of dark lines marked around the relief to emphasise its volume. The analysis made by the University of Barcelona revealed the presence of pyrolusite pigment. We found no similar traces of polychromy on any other part of the façade.

Laser cleaning test. Photo: Arcovaleno Restauro, SL

www.centrederestauracio.gencat.cat

Presence of lichens Before the intervention there were numerous epilithic crustose lichens. These lichens grow adhering strongly to the substratum, and are yellowish green and orange in colour. When they die, they turn dark grey, and can be mistaken for black crust. They are found in parts of the façade that are exposed to the elements, particularly to channels of water, as we can tell from the extension of the affected area, on cornice joints and in damp spots. Also associated with the growth of plants, they spread across stone and mortar joints. Biological colonisation Presence of lower and upper plants. We identified moss and pellitory-of-the-wall, the former only beneath the cornice and on the serrated frieze, and the latter in areas directly exposed to water, together with the lichens. Furthermore, pellitory is rooted in soft substrata, such as the spots where mortar joints are RESCAT

Centre de Restauració de Béns Mobles de Catalunya

weak or non-existent, and was found under the cornice, in the lower part of the rose window, above the archivolt of the monumental entrance, on the windowsills and on the sarcophagous lodged to the left of the monumental doorway.

often associated with areas of ashlars that have suffered fissures, as in advanced states of cracking the material can even collapse. According to the geological structure of the stone, this may produce the irregular and angular surfaces, whereas losses in the form of stars are usually associated with the impact of bombs.

Limestone concretions White in colour, like stone, and in the form of flakes or irregular horizontal flutes, the concretions are found all over the façade and affect ashlars old and new. The map shows that the concretions spread vertically, often together with the ashlar joints, on spots in contact with water. Their morphology and location seem to suggest that they are newly formed calcite produced from the dissolution of the limestone and its recarbonation. Black crust Varied in colour and thickness – blacker in the thickest areas and greyish in the thinnest areas, occasionally combined with the orangecoloured patina – the black crusts were found in areas sheltered from the elements, i.e., inside windows, in the monumental entrance and in the upper area of the outer circle of the rose window. Occasionally, under the hard layer of the crust the stone was pulverulent (sulphated). Exfoliation Exfoliation, which was only found on a few old ashlars, is a disease that affects the entire façade and doesn’t seem to bear any relation with water. The alterations could be caused by the nature of the stone or by weather phenomena such as icing and thawing.

Cleaning of a column of the monumental doorway Photo: Arcovaleno Restauro, SL

Circle of the rose window during the laser cleaning Photo: Arcovaleno Restauro, SL

Details of the façade after the intervention Photo: Arcovaleno Restauro, SL

Yellowish-green and orange crustacean lichens, alongside dark grey dead lichens Foto: Arcovaleno Restauro, SL

Fissures in the ashlars In this case we have only pointed out the ashlars with a grid of fissures or significant single cracks. The fissures are often accompanied by small losses of stone that determine an irregular surface. The degradation affects left half of the lower body much more than other areas, probably due to the high number of new ashlars on the right. We may deduce that the fissures in the ashlars were caused by climatic factors such as thermal impact generated by ice and its thawing. Losses Some losses resemble stars with sharp angles, others are lacunae that form rounded corners or else appear on the surface, which is hence angular and irregular. Losses are

RESCAT

Pellitory-of-the-wall growing in the joints between the blocks of ashlar and the window Foto: Arcovaleno Restauro, SL

www.centrederestauracio.gencat.cat

Orange-coloured patina Our observation before, during and after the intervention enabled us to identify traces of an orange-coloured patina in many areas such as the monumental entrance, in much of the rose window, inside the other windows, on the old ashlars of the upper and lower sections, on the pink mortar joints, under the concrete mortar joints, on the damaged ashlars (with cracks and loss of material), etcetera. The organoleptic examination did not establish the origin of the patina, which we think could be multiple. On the one hand, an artificial patina could have been applied after the façade was built, as we see above all on the monumental entrance and the rose window, and on the other, it could be a biological patina produced by lichens or bacteria, particularly on the ashlars. The chemical analysis carried out by the University of Barcelona revealed the complexity of the materials found in the rose window, the doorway and the window, where the composition of the patina varies: artificial on the entrance, probably applied to ensure chromatic homogeneity; biological on the window, formed by bacteria; and both types on the rose window (biological, formed by bacteria, and artificial, applied to achieve chromatic homogeneity of the replica). Conservation-restoration process Removal of plants and disinfection of joints and ashlars Our first intervention consisted in removing the superficial deposit accumulated on the horizontal surfaces using vacuum cleaners and thin flat brushes. The next step was to remove the moss and pellitory-of-the-wall, either manually or with spatulas and thin flat brushes, including the roots and other remains that could produce new shoots. The discontinuous joints between ashlars, those that are open or without cohesion, were scoured by hand using mechanical tools. The fragments of ashlar stone that had become detached or had been poorly adhered were removed from specific spots.

RESCAT

Centre de Restauració de Béns Mobles de Catalunya

Biological control and chemical cleaning Biological colonisation, in particular the presence of lichens, was one of the most obvious alterations on the façade. For this reason, the biological control and chemical cleaning were important parts of the intervention. The treatment consisted in administering by nebulisation the biocide Biotin T (made by CTS and based on octylisothiazolinone and quaternary ammonium salts) diluted to 1%. The application was repeated, after which all the affected areas were cleaned with a hydroalcoholic solution, brushes and sponges. Sandblasting The mechanical cleaning through sandblasting was only performed in some parts of the upper section and inside the two windows to remove the more resistant black crust. In the sandblasting process, 0.3 - 0.6 mm aluminium silicate (made by MPA, Materias Primas Abrasivas) was blown under a pressure of 2 to 4 bars with a 3 mm nozzle machine, at an angle of 60 - 90º. According to the hardness of the material to be removed, the distance of projection varied from 5 to 20 cm. The result obtained was satisfactory, as we managed to remove the black crust and homogenise the legibility of the monument with the rest of the façade. Laser cleaning Laser was considered the most appropriate method for the sculpted areas as it enables selective and very precise cleaning. A test was carried out on the right jamb of the monumental doorway using a Q-Switch Neodymium-doped Yttrium Aluminium Garnet (Nd:YAG) laser, which proved highly satisfactory as it enabled us to remove virtually all the black crust without affecting the original stone surface and without endangering the underlying orange-coloured patina. Consequently, we decided to use laser on all the reliefs of the monumental entrance and the rose window that revealed deposits of black crust. Adhesion of detached elements The fragments of detached stone were glued with the Ceys product Araldite Rapid epoxy resin, and were stuccoed with the lime mortar used in the reintegration we shall describe next. Reintegration When we speak of conservative repair, as in this case, we follow the principle of minimum

RESCAT

View of the façade after the intervention (January 2013). Photo: Arcovaleno Restauro, SL

Details of the façade after the intervention. Photos: Arcovaleno Restauro, SL

GENERIC CLASSIFICATION: Architectural heritage element OBJECT: Main façade and monumental entrance MATERIAL / TECHNIQUE: Stone of Girona and sculpted marble, with remains of polychromy | DESCRIPTION: Façade divided into two orders, separated by a flat cornice, the opening of a large rose window and a monumental entrance, both of which are sculpted with decorative reliefs and figures | DATE / PERIOD: Twelfth and thirteenth centuries | DIMENSIONS: Approximately 160 m2 LOCATION: Monastery of St Peter of Galligants, Girona (Gironès) CRBMC REGISTRATION No.: 11502 | COORDINATION: Pere Rovira RESTORATION: Arcovaleno Restauro. Direction: Rudi Ranesi. Team head: Davide Belfiore. Conservators-restorers: David Mallorquí and Albert Vila. Alteration maps and drafting of the report: Kusi Colonna-Preti | YEAR OF THE RESTORATION: 2012

intervention that could be considered the basis of all restoration charts and derives from the theories developed by Cesare Brandi that are still current. Of course, this notion doesn’t only refer to the phase of reintegration, but is also applied to the other two stages in conservationrestoration processes, i.e., cleaning and consolidation. In material reintegration, however, and above all in architectural restoration, it is particularly relevant. Indeed, in this area Brandi’s theories have not yet found full acceptance and still arouse concerns due to the presumed dichotomy between the structure function of the buildings and their style and conservation.

www.centrederestauracio.gencat.cat

The restoration of St Peter of Galligants exemplifies a type of practice that is increasingly common in the field of architectural restoration, thanks to the large number of specialised firms that have adopted the use of restoration charts and have introduced conservative practices previously explored in the plastic arts into the field of architecture, a process supported by the institutional role played by the Centre for the Restoration of Movable Property of Catalonia (CRBMC, for its initials in Catalan). In other words, in this intervention, the aforementioned dichotomy between form and function can be overcome thanks to the use of appropriate methodological practices. When we began our intervention, a number of lacunae of different sizes were visible on the stone, predominantly radial fractures obviously caused by the impact of bombs dropped during the Napoleonic Wars. The relevance of such a historical event made it advisable to avoid at all costs replacing the ashlars affected by the impacts, even those that were more deteriorated, and painstakingly micro-seal the fractures instead, to obtain a solid surface that would at the same time show the scars of the war. In this case, special care was taken to create a surface able to discharge rainwater. An overhanging canopy above the archivolts frames the opening of the monumental entrance and protects the reliefs from rainwater. Some losses of material, however, prove that the stone had come into contact with water, which had affected the patinas and entailed a risk of erosion of the reliefs. In these cases it was necessary to restore the original function of the canopy. On the advice of the territorial architects and of the CRBMC, we decided to install a new zinc canopy that would protect the original from the elements. As a result we avoided having to touch the original blocks of stone, complying with our aim for minimum intervention in constitutive materials. Sealing of joints Joints were sealed with different types of mortar, hydraulic lime-based mortar and sand, according to the shade of the stone. The excess of lime on the surface was removed with sponges so as to allow the texture of the mortar to show through. Those spaces or joints that measured more than 3 cm in width were sealed with coarse sand-lime and then covered with surface joint mortar, applied slightly under surface level.

RESCAT

Centre de Restauració de Béns Mobles de Catalunya

CONSERVATION–RESTORATION

INTERVENTION ON A POLYCHROME WOODEN ALTARPIECE

The doors of the Madonna of the Rose Bush altarpiece from St Felix of Cartellà church THE PANELS WERE SAVED, despite the decayed state of the support, facilitating the reading of these fragmentary pieces. In 2016 two panels belonging to an altarpiece entered the Centre for the Restoration of Movable Property of Catalonia (CRBMC, for its initials in Catalan) to be restored. According to the last identification made by Joan Bosch and published in the review Locus Amoenus, they depicted St Peter and St John the Evangelist. The historian also pointed out in his article that the doors could well have formed a part of the Rose Bush altarpiece by painter Joan Baptista Toscano. Originally from Lombardy, Toscano was active in Catalonia between the years 1595 and 1617. He is also the author of the high altarpiece of Sant Andreu de Llavaneres (1603-1611).

Blueprint/guide on transparent acetate. Position of the fragments of door no. 2 Drawing: Marta Estadella

RESCAT

State of the support when it arrived at CRBMC

Panel 1, St Peter, before our intervention

of saliva, wood, excreta and soil. Then, in the second door (St John the Evangelist) we attempted to reference the position of eleven fragments with traces of polychrome paint. Although it wasn’t easy to determine their exact situation, we turned all the fragments around and looked at them from the rear, thanks to which we managed to roughly establish their original positions. The next step was to draw each profile on a transparent acetate sheet and place the different fragments in their approximate position, given that the cleaning process would necessarily entail the loss of some information. The large areas without support made it necessary to introduce wooden inlays, for which we chose cedar, a type of wood that is appreciated for its density and because it is not prone to suffer the attack of xylophagous insects.

State of conservation The two panels arrived at CRBMC in a state of great decay. Attacks by xylophagous insects – most of them termites – and, to a lesser extent, attacks by woodworm had damaged much of the wooden support of both doors, and a significant part had been lost. Despite the gravity and the state of decay in which the doors arrived, at first glance their extreme state of decomposition was not obvious. During the examination we made of their interior we discovered that in some cases, beneath a fine layer of wood, only the polychrome paint and the ground were visible. Process of conservation and restoration To intervene on the support was of utmost importance in order to save the work, and so the first step was the application of paper facing to the paint layer, covering practically the whole of the polychromy to be able to work safely without losing the paint. The fragments that arrived were cleaned before the decayed wood that couldn’t be saved was removed, along with the cells and interior structures built by termites, forming a mixture

Marta Estadella, conservator and restorer of polychrome wood and sculpture

GENERIC CLASSIFICATION: Polychrome wood OBJECT: Fragments of altarpiece| MATERIAL / TECHNIQUE: Oil and tempera on wood DESCRIPTION: Door no. 1, St Peter, and door no. 2, St John the Evangelist | DATE / PERIOD: Joan Baptista Toscano. Woodwork by carpenter Ramon Roca, late sixteenth century DIMENSIONS: 162.8 x 39 x 2.3 cm (door 1) and 164 x 60 x 2.3 cm (door 2) | LOCALITION: St Felix of Cartellà church, Sant Gregori (Gironès) CRBMC REGISTER NOs.: 12428.1 and 12428.2 COORDINATION: Josep Paret | RESTORATION: Marta Estadella (support), Victòria Homedes and Glòria Flinch (polychrome). Intern student: Makoto Isawa. Scholarship assistants: Laia Duran and Núria Jutglar | CARPENTRY AND CABINETMAKING: Carmelo Ortega YEAR OF THE RESTORATION: 2016

Panel 2, St John the Evangelist, before our intervention

www.centrederestauracio.gencat.cat

RESCAT

Centre de Restauració de Béns Mobles de Catalunya

Detail of the configuration of the parquet in door no. 1 Photo: Marta Estadella

Detail of the slats in a fragment of door no. 2. Photo: Marta Estadella

Positioning of the slats in the lower area of door no. 2 Photo: Laia Duran

Detail of the procedure followed to establish the distance between the sheets of wood in door no. 2 with the help of the acetate and the wooden bridges. Photo: Marta Estadella

Two different techniques were used in this volumetric reintegration: on the one hand, the wood was placed at two levels, following the French method, with slats of different widths and lengths that would gradually adapt to the areas devoid of support; and on the other, losses were filled with strips of wood to create an area that could have a structural function, or move and adapt to the relief of the original support. In some cases, dilatation joints were made with balsa wood, once the strips of wood had been insulated with acrylic resin. An acrylic adhesive was used to secure the non-structural inlays to one another and to the support, whereas the structural inlays were sealed with a polyvinyl adhesive. Once the original surface had been waterproofed, an epoxy resin was applied to the uneven area between these structural inlays and the support, which was very irregular. The fragmentation of the inlays enabled us to reduce the force of contraction and thus avoid possible movements in the future and ensure the maximum adjustment to the original support, and the maximum reduction of the necessary adhesive and filler. One of the inlays was glued following the curve of the original panel of wood, in order to minimise the effect of the deformation of this panel. The positioning of the interior inlays in the second door where the two panels come together was more complex and involved the construction RESCAT

of a bridge system of provisional pieces of wood that could be moved and fixed in order to establish the correct reference distance between the panels – previously unknown – before defining the area in need of reconstruction, thanks in part to the central fragments. The adhesive used to join the central inlays in the two planks of wood was codfish glue, chosen because it is reversible and because it enables the two planks of wood to be separated, if necessary, without interfering with the adhesive used in the construction of the inlays. Finally, all the inlays that had been deliberately glued on top of the surface were levelled out, as the thickness

Panel 1: Obverse following our intervention on the support

View of all the inlays in position in door no. 2. Photo: Laia Duran

Panel 1: Obverse following our intervention on the support

View of the piece of original crosspiece positioned with neodymium magnets Photo: Marta Estadella

Possible application of the system of anodised aluminium profiles developed at CRBMC Photo: Marta Estadella

www.centrederestauracio.gencat.cat

RESCAT

Centre de Restauració de Béns Mobles de Catalunya

of the inlays was irregular; they were also dyed to give them a uniform finish. The remaining fragments of the second door were in a terrible state of conservation. Despite preserving some of the polychrome paint, the support was completely deteriorated, either void or full of galleries plastered with the waste of termites, and therefore in need of cleaning. After studying various possible options, we decided to remove the remains of the support and leave the fragments of polychromy so they could be adhered to the new wooden inlays, taking as a guide the plastic acetate with the blueprint of their original position.

Panel 2: Obverse following our intervention on t he support

Panel 1: Last photo after the conservation and restoration

Creation of the crosspieces Practically all the crosspieces of the two panels had disappeared, with the exception of a small part of one of them, which made it necessary to

The two panels hanging once more in the apse of the church of St Felix of Cartellà, in the town of Sant Gregori (Gironès)

design a new system, based on springs to ensure its maximum mobility. We reduced the number of crosspieces in both panels, although the width and thickness of the originals were respected to make sure they didn’t coincide with the areas of the inlays, and the surfaces have been made as flat as possible. In the first door, the width of the new crosspieces was reduced because the size of its original is not known. In the new system, a series of wooden pivots was placed in strategic points of the panel. Each pivot was attached to the support with epoxy resin and has a stainless steel countersink screw. The screw is fixed to the wooden pivot but not to the support, thus enabling it to move freely, and then the crosspiece is placed between the pivots. At each pivot, the stainless steel screw enters an L-shape made of perforated aluminium, and in order to fix the crosspiece in position, a spring is placed on top of the L and through the screw, and then fastened with nuts and washers. So in the event of vertical extension and contraction (warping), the spring may compress,

Panel 2: Obverse following our intervention on the support

Panel 2: Last photo after the conservation and restoration

RESCAT

www.centrederestauracio.gencat.cat

whereas the crosspieces may resist horizontal extension and contraction thanks to the horizontal movement enabled by the holes in the aluminium profile. The technique can also be combined with anodised aluminium profiles for altarpieces developed at CRBMC by Josep Paret, as the latter allows the regulating systems to remain visible in future examinations and therefore, if necessary, to be adjusted without the piece having to be disassembled from the structure. The partially preserved crosspiece that had lost its original function was reintegrated with the parquet system in the areas where it was missing. It is adhered to the support of the door by two neodymium magnets thank to which it remains in its original position and yet may be moved if necessary. Once the conservation and restoration of the wooden support of the panels was completed, the intervention went on to treat the layer of paint and the adherence of the fragments of preserved polychromy to the new support. RESCAT

Centre de Restauració de Béns Mobles de Catalunya

CONSERVATION–RESTORATION

Irene Panadés and Maria Sala, painting conservators-restorers, and Sofia Mata, director of the Diocesan Museum of Tarragona

INTERVENTION ON PAINTING ON CANVAS

and for this reason delivered the lecture entitled ‘Concerning a Painting Attributed to Antonio Viladomat during his Tarragona Period’ at the First International Conference of EighteenthCentury Spanish Painting. The most recent studies dedicated to the painter by Francesc Miralpeix accept the attribution of the pietà to Antoni Viladomat, establish its arrival in our city around the year 1704 and include it in his catalogue.

A pietà from the Diocesan Museum of Tarragona attributed to Antoni Viladomat i Manalt THE VICISSITUDES SUFFERED by this work over the course of time, especially as regards the restorations that it has undergone, are the main reason for this intervention. History of the Work, by Sofia Mata, Director of the Diocesan Museum of Tarragona (MDT) Sra Enriqueta de Castellarnau i Miró, the last owner of Casa Castellarnau on Carrer de Cavallers in Tarragona, sold the property to Tarragona City Council in 1954. The premises now house the technical services of the Museum of the History of the City. This was probably the date of the donation she made to the chapel of Our Lady of the Cloister in Tarragona cathedral: a pietà or a lamentation painted in oil on canvas; a work that revealed its pictorial quality in spite of the dark patina masking the figures. It came with an interesting frame of carved wood. When the collection of the Diocesan Museum was revised around 1989-1990, a typewritten note was found adhered to the back of the work, which attributed it to painter Antoni Viladomat and included a few biographical details. Unfortunately, the note was removed in 1992 during a quick restoration process and is now considered definitely lost. Before the year 1986 a series of paintings that were kept in the chapel, among which was the pietà, were transferred to the Diocesan Museum in Tarragona that at the time occupied adjoining premises. Its quality, its attribution to Viladomat and the fact that it is unknown to art history were the reasons for its inclusion in the show entitled Pallium. Exhibition of Art and Documentation. Tarragona Cathedral organised by the Tarragona Regional Government in1992. In the exhibition catalogue, priest Romà Comamala associated its execution with Viladomat’s Tarragona period when, according to Antonio Ponz, the painter appears to have worked at the College of the Society of Jesus, at St Tecla’s and St Paul’s Hospital and other places in the first decade of the eighteenth century. Writers like Immaculada Socias supported the attribution to Viladomat, RESCAT

Detail of the angle showing the original canvas and the relining canvas

Initial photograph of the obverse

Initial photograph of the reverse

Infrared photograph of the obverse

www.centrederestauracio.gencat.cat

Examination and diagnosis of its condition The support of the picture is canvas mounted on a stretcher that is not the original stretcher. Its upper edge is quite distinctive as it is curved, its angles are aligned with the outline of the frame, and with a horizontal crosspiece that keeps the wedges in place. It hasn’t suffered damage caused by xylophagous insects. The painting has been relined, albeit the canvas had no significant deterioration. This was a routine practice at the time and yet proved detrimental to the work, not only because it concealed information regarding the original support but also because it affected the layers of paint, made the impastos vulnerable and sometimes marked the weft of the canvas on the pictorial surface as a result of excess heat or the pressure that such treatments might entail. The thread of the added canvas is fine and its weft is taut. It has been adhered with wheat starch paste and glued to the stretcher along its perimeter. The original canvas is a plain weave fabric with a density of 12 x 12 cm2, and is well adhered to the lining. Grime and accumulated dust are found on the back. The ground is traditional and reddish in tone, befitting the painter and the period, over which the oil paint has been applied in a few brushstrokes. The two layers are well adhered to one another and to the support. The polychromy has two small losses, widespread cracks in the surface with no risk of detachment, and general wear in the upper area, possibly produced by previous cleaning. Examination of the pictorial surface with raking light and ultraviolet light (UV) revealed a general layer of dark, yellowish varnish that doesn’t seem to be the original varnish. We also found traces of repainted areas resulting from previous restorations and insect excreta. The wooden frame with gilt and polychrome mouldings has been the object of many interventions and shows signs of much repainting, quite a thick layer of bright varnish and volumetric reintegrations of the wood RESCAT

Centre de Restauració de Béns Mobles de Catalunya

PLACE FROM WHERE THE SAMPLE WAS TAKEN

ANALYTICAL TECHNIQUE

SUMMARY OF RESULTS

M1 Varnish on the right section

GC/MS chromatography

Varnish: Mastic resin (triterpenoids) Rosin (diterpenoids)

M2 Varnish (removed with a swab)

GC/MS chromatography

Mastic resin (triterpenoids) Rosin (diterpenoids)

M3 Edge area

M6 Horizontal thread. Original canvas of the support M7 Vertical thread. Original canvas of the support

losses. The reintegrations made with Araldite, a two-component epoxidic resin (Araldite SV427 + HV427), were not very accurate as they covered original areas and their thickness was irregular due to an excess of material and unevenness. Beneath these strata produced by the aforementioned restoration we discover an earlier intervention that consisted in alternate gilt and white paint on the mouldings. This layer covers the ‘mecca’ gilding, which is probably original, of which we ignore the scope and degree of losses. Moreover, the frame has quite widespread losses of gilt and numerous holes produced by insects. On the reverse, part of the original wood has been replaced by new wood. It also shows several whitish stains, and in the lower right-hand corner contains remains of sealing tape and superficial dust. The canvas is attached to the frame by ten metallic nails and it hangs from a single ring and shackle. We confirmed that the work had been subjected to earlier restorations that have not been documented. The canvas had been relined and several layers of darkened and repainted varnish had suffered alterations. To conclude, we could say that the condition of the work before our intervention was satisfactory. Both the paint and the support (original canvas, relining and stretcher) were Removal of the varnish. The process revealed the degradation of the canvas

RESCAT

M10 White (area of the shroud of Jesus)

M11 Blue (dress of the Virgin Mary)

Stratigraphic analysis of the section under ultraviolet light (UV) Optical microscopy (OM) magnified 500 times Optical microscopy (OM) enables a comparative study of fibres

Three strata and the support are identified. The canvas of the support. In the section of the fibres we distinguish polygonal shapes with small interior lumens, which are Liberian fibres (linen)

The two threads are made of liberian fibres (linen)

White polychromy: presence of white lead (2PbCO3·Pb(OH)2), and Prussian blue, in small proportion (Fe4[Fe(CN)6]3 ) Binder: Oil. Presence of carboxylates of lead formed by the effect of the saponification of fatty acids with the lead in the pigment

µFTIR

Prussian blue

µFTIR Dispersion of the sample of a diamond cell

M5 Gilt of the frame

Optical microscopy (OM)

Stratigraphic analysis of the sample of gilt under polarised light that emphasises the gilt sheet

M8 Gilt of the frame

Optical microscopy (OM)

Stratigraphic analysis of the sample of gilt under polarised light that emphasises the silver-gilt of the plate

M9 Gilt marc

Optical microscopy (OM)

The stratigraphic analysis reveals that the ground is made of synthetic resin, which indicates that in this case the sample is from a previous intervention

M4 Frame Varnish (green area)

Optical microscopy (OM) Stratigraphic analysis under ultraviolet light (UV)

www.centrederestauracio.gencat.cat

As in the case of sample 9, this stratigraphic analysis also consists of a synthetic ground. The red fluorescent layer emphasised by this kind of lighting is shellac resin that presents another yellow intervention

RESCAT

Centre de Restauració de Béns Mobles de Catalunya

UV-light photograph taken to confirm the vanish had been correctly removed

Final photograph of the obverse

stable, but the picture had been darkened and yellowed by the deterioration of the superficial varnish. The frame was in a poorer condition, both on account of the attacks by xylophagous insects and of earlier cursory restorations. Analysis The painting was examined by X-Ray, with ultraviolet light (UV) and infrared reflectography (IRR). The samples taken were subjected to stratigraphic study to compare the fibres of the support, identify the components of the primer, the binder, certain pigments and the varnish of the repainting. Some of the results of the analyses can be seen in the table at the end of this article. Process of conservation–restoration The picture was unframed before entering the workshop and the frame was disinsectised in the anoxic chamber. The rust on the tacks was mechanically removed before they were treated with a solution of 3% tannic acid. We began by vacuum cleaning the reverse of the canvas, and using a water and ethanol solution for the wood of the stretcher. The pictorial surface was also vacuumed in order to remove inorganic superficial dirt. This preliminary treatment is indispensable, as the removal of the inorganic layer and of the soluble salts deposited on the varnish makes it easier for us to choose a less polar solvent to remove added substrata. The next step was measuring the conductivity and pH of the pictorial surface, studies RESCAT

Final photograph of the reverse, showing the new framing system and the Velcro used to adhere the protection

GENERIC CLASSIFICATION: Painting on canvas OBJECT: Picture and frame | MATERIAL / TECHNIQUE: Oil on canvas | DESCRIPTION: The Lamentation of Mary DATE / PERIOD: Baroque | DIMENSIONS: 79 x 101.5 cm (framed) and 57.5 x 78 cm (unframed) | LOCATION: Diocesan Museum of Tarragona (MDT), (Tarragonès) | CRBMC REGISTRATION No.: 12939 | INVENTORY No.: MDT 3271 | COORDINATION: Maite Toneu Puig | RESTORATION: Irene Panadés and Maria Sala PHOTOGRAPHY: Ramon Maroto | X-RAYS: Esther Gual PHYSICAL-CHEMCAL ANALYSES: Ricardo Suárez ANOXIA: Pep Paret | YEARS OF THE RESTORATION: 2014 - 2015

www.centrederestauracio.gencat.cat

complemented by the CRBMC aqueous test of buffer solutions in order to find the most appropriate aqueous solution, according to the suggestions made by Paolo Cremonesi and Richard Wolbers. The following stage in the process consisted in testing the work to determine the composition of the solvent needed to remove the varnish, and establish the best application method. We decided on a combination of polar solvents and took measures to control their penetration, thanks to which we avoided any interaction with the original layer and minimised the risks of lixiviation of the internal area of the pictorial layer. This control followed the principles set out in the studies of solvent retention carried out by Liliane Masschelein-Kleiner and those of gel media by Richard Wolbers. In the last phase of the restoration of the painting we used traditional gesso made of rabbit-skin glue and calcium carbonate to level out the lacunas that had led to the loss of ground, and employed watercolours for their chromatic reintegration following illusionistic criteria. The last step was the application of a layer of a resin of low molecular weight resin with a small flat thin brush. The treatment of the frame consisted, in the first place, of an overall mechanical cleaning by vacuuming, followed by aqueous cleansing of the reverse with water and alcohol. The cleaning of the obverse was performed in two stages: first, a non-conservative aqueous cleaning of the varnish, and then cleansing with a blend of gellified and liquid solvents to remove the varnish and the areas of repainting, and to soften the epoxidic resin (Araldite) that was subsequently either diluted or mechanically removed with a scalpel. In the last stage of the restoration of the frame, the areas with loss of support caused by the attack of wood-eating insects were levelled out with a walnut coloured filler. Watercolours were used for the chromatic reintegration, vertical hatching for the areas of gilt and illusionistic retouches in the other areas. Finally, Laropal A 81 varnish of low molecular weight was applied. The reverse of the work was protected with Tyvek 1443R fabric made of high-density transpirable polyethylene fibres to protect it from dust and dirt, and to reduce to a certain extent variations in humidity. RESCAT

Centre de Restauració de Béns Mobles

INNOVATION AND RESEARCH

STEPS TOWARDS A SYSTEM OF VOLUMETRIC REINTEGRATION BY 3D-PRINTING FOR LIGNEOUS SUPPORTS The final presentation in the conservationrestoration of cultural heritage is a moment for debate and discussion, and provides a wide range of possibilities for conservators and restorers.

and finally Bamboo. In comparison with natural wood, only the test specimens with an interior density of 0% or 20% have a similar or inferior weight, except in the case of PLA Extra, which at 20% is already heavier than wood. The next step involved carrying out the following tests:

In today’s context of new technologies within the speciality of Painting and Sculpture on Wood at the Centre for the Restoration of Movable Property of Catalonia (CRBMC, for its Catalan initials) we decided to study the viability of 3D-printing of imitation wood materials for the reintegration of losses in the ligneous supports of cultural heritage. For the time being, the results of this study have only been applied to the restitution of lost volumes in the repetitive elements of works; in other words, instead of hypothetical recreations we propose copies of conserved elements. The materials used in conservation and restoration must meet a few basic requirements: stability, reversibility, innocuousness and compatibility with the original. Consequently, the tests carried out during this attempt to typify the materials and verify their workability have borne these criteria in mind. Four PLA (polylactic acid)1 filaments for 3D printing were chosen, and using a domestic 3D FDM printer (Fused Deposition Modeling)2 we made test mock-ups measuring 2 x 2 x 2 cm. One of the filaments consists only of PLA resin (PLA Extrafill) and the others also contain recycled wood fibre (WoodFill), bamboo (BambooFill) and cork (CorkFill) in variable proportions of 20% to 30%, according to the manufacturer. Two cubes made of pinewood and cedar bossé were also made, of the same size, in order to compare results. The 3D printing enables us to choose the 2 x 2 x 2 cm test specimens with density of the interior of the pieces, BambooFill and so they were tested at 0%, 20%, 50% interior densities and 100%. We began by weighing of 20%, 50% and 100%. The exteriors the cubes with a 0.01gr. precision are compact, and scale, an operation we repeated with have a thickness of at least two samples, to obtain the 1.2 mm. Photo: Laia Duran weight of the materials. The densest and Núria Jutglar is PLA Extra, followed by Cork, Wood

A. Polishing. Filler application The polishing was carried out on the edge and the side using sandpaper (numbers 3 and 6). In general terms,

B. Retouches. Varnish. Papelgel Three flat colours were applied by means of the artistic procedures habitually used in chromatic reintegration: gouache by Talens, Laropal A 81 resin in ShellSol A35 and D40 and Winsor & Newton pigments and watercolour. The application, adherence and coverage of the gouache and varnish with pigments are good. The watercolour doesn’t adhere well to the support in spite of having added a surfactant to it (ox bile). We also used a 10% solution of Paraloid B-72 acrylic resin and Regalrez 1094 polycyclohexanol resin in different concentrations (10%-40%) as varnish. Both yielded good results in terms of adherence. A test was carried out with a system called Papelgel for transferring images to three-dimensional surfaces. In order to ensure a correct transfer we recommend applying a layer of adhesive. We used Acril AC33 emulsified in white spirit (40% to 60%), and the resulting transfer has very few gaps. The polishing of the test specimens (WoodFill, CorkFill and BambooFill) yields good results, despite the differences in behaviour compared to natural wood (cedar bossé and pinewood). Photo: Laia Duran and Núria Jutglar

The application of traditional filler on the WoodFill test specimen showed good adherence and drying without cracks. Photo: Laia Duran and Núria Jutglar

Printing process with a Prusa i3 printer of one of the test specimens with WoodFill filament. Photo: Laia Duran and Núria Jutglar

The gouache retouching of the test-specimen surface also showed good adherence. Photo: Laia Duran and Núria Jutglar

Watercolours do not adhere well to the PLA Extrafill. Photo: Laia Duran and Núria Jutglar

Polylactic acid (PLA) has similar properties to those of polyethylene tereftelate (PET). It’s a biodegradable and bioactive thermoplastic obtained from cornstarch (USA), yucca or cassava roots (Asia) and sugar cane (rest of the world). 2 Fused deposition modelling (FDM) is an additive manufacturing (AM) technique. The printing process consists in laying down the material in layers to create the piece in question. The printer we used was a Prusa i3 with Cura 15.04.6 printing software. 3 WoodFill, BambooFill and CorkFill, by ColorFabb, and PLA Extrafill Light Ivory, by Fillamentum have a printing temperature of 200-210º C.

the reaction was positive. The material can be reduced without becoming deformed. Unlike wood, it doesn’t disintegrate into dust but remains agglomerated, adhered, and is consequently easy to remove. It can also be polished in all directions. The densest filaments, Cork and PLA Extra, are the hardest. Applied with a spatula, the filler (whether synthetic, like Blummestukko, or traditional) has yielded good results. It has a good adherence, except in the case of the traditional filler on PLA Extra, which produces a slight incohesion. It dries very well and shows no cracks. Balsite epoxy-based putty yielded good results when applied with a spatula and as regards its adherence to surfaces. After exerting a slight tension on a piece of adhered wood, the superficial filler also showed a high cohesion.

RESCAT

www.centrederestauracio.gencat.cat

Laia Duran and Núria Jutglar, conservators-restorers of cultural assets

C. Solvents: ethanol, ethyl acetate, xylene and acetone The choice of these four solvents was based on existing

Removing the moist Papelgel. The transfer is performed correctly and the inks remain on the surface without gaps. Photo: Laia Duran and Núria Jutglar

RESCAT

Centre de Restauració de Béns Mobles

INNOVACIÓ I RECERCA

Test specimens with an interior density of 100% can be drilled successfully, despite presenting a greater resistance and residues parallel to the printing plans. Test with BambooFill. Photo: Laia Duran and Núria Jutglar

Set of specimens after the tests had been performed. Photo: Jennifer Sánchez

Slight whitening of the surfaces rubbed with cotton balls soaked in acetone. Photo: Laia Duran and Núria Jutglar

bibliography on acid polylactic, that determined that it was soluble in polar aprotic solvents but insoluble in polar protic and apolar solvents. They were applied by rubbing with a swab. In the case of ethanol, no effect could be seen on the surface. In those of the ethyl acetate and acetone, the first consequence is a general softening, followed by a fine whitening of the surface and a slight staining of the balls of cotton (to a greater degree in that of the acetone). The xylene doesn’t seem to produce the softening, although it does produce a slight whitening effect, especially on the PLA Extra. D. Mechanised: drill We used an electric drill with a 4.5 mm bit for iron to bore a hole measuring 1.5 cm in depth, and attached the test tube to the carpenter’s workbench. Even though in principle the material (like natural wood fibres) has no direction, we did foresee different reactions produced by the printing and the filament deposit according to how it was positioned, whether vertically or horizontally. Each test tube was drilled perpendicularly to the printing layers and in parallel. We also studied the different mechanical reactions according to the density of the material, tested at

densities of 20%, 50% and 100%. At 20% and at 50% it is easy to work in both directions, while at 100%, horizontally (i.e., parallel to the printing plans) the material is much more resistant and the residues melt and remain adhered to the bit. We should not forget that at higher densities, more residues are generated close to the orifice and the resistance of the interior is more like that of the exterior of the test tube. Of all the filaments, PLA Extra and Cork are the hardest. Conclusions All the filaments tested have produced acceptable results, and are therefore adequate for use in the field of conservation and restoration, applicable according to each specific case. Nevertheless, we consider BambooFill printed at 0% or 20% ideal, in terms of density and resistance, correct handling and organoleptic features (texture, surface, colour). PLA Extra is the cheapest, but is denser and less porous than the filaments containing wood, bamboo or cork fibres, which reduces their workability and versatility in reintegration:

From left to right: reproduction and original of a decorative element in the 18th-century altarpiece from St Christopher’s of Toses church, Ripollès. Example of the restitution of lost repetitive elements. The original image is captured and processed by photogrammetry and printed at an interior density of 0%. Photo: Laia Duran and Núria Jutglar

Papelgel is a flexible and colourless material that can be applied to uneven surfaces for printing with ink jet printers. After printing, the material is moistened, which enables the inks to be transferred to any surface or volume. Today this technique of chromatic reintegration is being used on different supports in restoration, particularly in the restoration of mural paintings. 5 A systematic study of PLA films immersed in several groups of solvents showed that these solvents resulted in the whitening and crystallisation of the films, even if they did not induce chemical changes in their structure. See Shuichi Sato, Daiki Gondo, Takayuki Wada, Shinji Kanehashi and Kazukiyo Nagai, ‘Effects of Various Liquid Organic Solvents on Solvent-Induced Crystallization of Amorphous Poly(lactic acid) Film’, Journal of Applied Polymer Science (2013), pp. 1607-1617.

the polishing and mechanisation are more complicated and the application of filler, pictorial procedures or solvents to surfaces doesn’t yield such good results. The acceptable result of the test of solvents leads us to believe that they were compatible with adhesives and other products used in restoration, but the pertinent tests have yet to be performed. It is also advisable to carry out aging tests to establish the stability and degradation of the polylactic acid. Broadly speaking, these materials enable us to choose the desired density, which makes them as versatile – or more – as traditional reintegration materials, be they wood of different densities, fillers or resins. However, the great advantage of this system is revealed when the multiple options of the process as a whole are postulated, over and above the suitability and density of the filaments. In a practical application, for instance, 3D prints can be a better solution than copies on wood or moulds due to their speed, precision, low cost,

RESCAT

www.centrederestauracio.gencat.cat

reproducibility and the facility with which they capture original volumes without touching the actual piece, by means of photogrammetry or 3D scanning. To conclude, 3D printing is a convenient and versatile option for the volumetric restitution of ligneous supports. For now it can be a useful tool for restorers as an easily reproducible and repeatable technique for material reintegration, in spite of its limitations in terms of size. Our acknowledgements to Jennifer Sánchez, intern at the Photography Department at CRBMC, Aleix Barberà, conservator-restorer at CRBMC, and Javier Márquez, computer engineer, for their collaboration in this study.

RESCAT

Centre de Restauració de Béns Mobles

ACTUALITAT

La difusión preventiva del patrimonio cultural

13th International Committee for the Conservation of Mosaics (ICCM) From the 15 to the 20 October, the Born Culture and Memory Centre in Barcelona hosted the 13th International Committee for the Conservation of Mosaics (ICCM) with the support of the Barcelona Archaeological Service and The Getty Foundation. Under the title ‘What Comes to Mind When You Hear Mosaic? Conserving Mosaics from Ancient to Modern’, the main subject of the conference focused on materials, techniques and conservative treatments of ancient mosaics and new types that have developed over the course of the twentieth century. Other themes emerged during the different sessions, including management and policies, methods of survey and documentation, conservation of mosaics from ancient to modern, presentation and display, education and training, and conservation and management of sites with mosaics. In the framework of the conference, the Centre for the Restoration of Movable Property of Catalonia (CRBMC, for its initials in Catalan) presented its project for the conservation of the mosaics of Empúries in the form of an exhibition staged at the Museum of Empúries, that opened the same day the delegates visited the site. The exhibition, educational in nature, was explained to the 180 delegates once they had had occasion to contemplate the mosaics during their tour of the site, and featured the characteristics of the mosaics, their history, the documentation carried out and, above all, the study and control of their biodeterioration and the restorations they have undergone. That afternoon, those taking part in the conference visited the Girona premises of the National Archaeological Museum of Catalonia, where they visited another display of mosaics restored by CRBMC, specifically the mosaic dedicated to Theseus and Ariadne from Bell-lloc del Pla. Sílvia Llobet and Pere Rovira

UN LLIBRE PER LLEGIR

Santos M. Mateos, Guillem Marca and Oreste Attardi Ediciones Trea, Gijón, 2016, 127 pages

THE USE OF GELS IN CONSERVATION Lecture Approximately five hundred and fifty people from thirty-nine different countries (according to information provided by the organisation) attended the lecture entitled ‘The Use of Gels in Conservation’ held in London from the 16 to 18 October 2017. The success of the event was anticipated almost five months before the opening of the conference, when all seats had been sold and a waiting list was created, so congratulations are in order to International Academic Projects Ltd., and the Tate for having jointly hosted an exceptional professional meeting in the field of conservation and restoration. The conference presented the most cuttingedge research on the use of gels in the restoration of cultural assets, in an interdisciplinary approach that combined analytical studies and rigorous scientific research with practical case studies of the use of gels. The studies were presented by Silvia Marín Ortega, lecturer at the Higher School of Conservation and Restoration of Cultural Assets of Catalonia, Rosa Senserrich-Espuñes, lecturer at the University of Barcelona, and Aleix Barberà Giné, restorer at the Centre for the Restoration of Movable Property of Catalonia (CRBMC, for its initials in Catalan) and visiting lecturer at the University of Lleida, all of whom also work in the private field. The results of the conference were compiled in Gels in the Conservation of Art by the scientific committee headed by Dr Richard Wolbers (University of Delaware), in collaboration with Lora V. Angelova (National Archives), Bronwyn Ormsby and Joyce H. Townsend (Tate). Published by the leading firm Archetype Publications, the book can be purchased online at https://www.archetype. co.uk/publication-details.php?id=250.

The authors of this study reflect on the necessary relationship between the conservation of cultural heritage and its social use, and put forth rules to help achieve a sustainable balance between the two. The edition is well structured. The study begins by setting out general theoretical approaches, which are put into practice in the last chapter. The book includes a wide bibliography and details of the materials used and recommended that are accessible online. The treatise, clear and didactic, is complemented by a number of photographic references (of good and bad praxis around the world), diagrams and quotes. Museums and other cultural heritage centres obviously need visitors to manage their hallmarks correctly. The book offers a range of communicative solutions for harmonising the relationship, raising visitors’ awareness through subtle, subjective means such as the interpretation of heritage, and especially through more direct and impressive means such as preventive measures designed to maintain and improve the state of collections and the environments in which they are displayed. These measures intend to transform predatory visitors into protective visitors, explaining and communicating instead of forbidding and concealing. The study examines the communicative strategy of preventive measures for objects during display, and their function in preventive conservation and the identity of the cultural heritage they protect. The last chapter presents an application model and an implementation guide, the Batiscafo Model of Preventive Interaction, which is especially interesting because it has recently been created by the authors of the book and is hypothetically applied to a real museum— the Museu Nacional d’Art de Catalunya (MNAC). This model intends to be a strategic guide for all sorts of heritage centres. The book hopes to provide collection managers, conservators and restorers of cultural assets with a plan of action for sensitising and educating their audiences, and enable visitors to interact with a vulnerable resource like cultural heritage in a sustainable way.

Enric Gracia Photographer of cultural heritage

Materials for Conservation. Organic Consolidants, Adhesives and Coatings

Velson Horie New York: Routledge, 2nd edition, New York, 489 pages The book, divided into two parts and an addendum, is a reference manual to the chief characteristics of consolidants and how they act in the realm of cultural heritage. In the first few chapters, Horie introduces a number of terms related to polymers, solvents, the concept of adhesion and the applications of polymers in the field of conservation and restoration. In the second part of the book we find a compilation of the different families of polymers and their main properties. All these concepts will help readers understand the consolidation process, providing them with the theoretical basis they need in order to grasp the technical terms employed in the following chapters and addendum. Finally, the addendum contains a series of tables showing the general properties and the physical and chemical parameters of the polymers and solvents introduced in the preceding chapters. In this section we also discover the origin of the most important solvents within the Teas Triangle. These parameters can be interactively accessed at no cost on the website of the Roman Istituto Superiore per la Conservazione ed il Restauro (ISCR): www.icr.beniculturali.it/flash/progetti/ TriSolv/TriSolv.html As a reference book, this is a very practical survey. Written from scientific and technical points of view, it contains graphs and tables that gather all the information required in order to choose the product best suited to specific conservation processes. On the other hand, however, it introduces concepts and technical terms that could prove difficult to understand for readers without sufficient scientific background, who could perhaps even find it confusing.

Ricardo Suárez Chemist at the Centre de Restauració de Béns Mobles de Catalunya (CRBMC) Ruth Sadurní Chemist and restorer. Intern at the Centre de Restauració de Béns Mobles de Catalunya (CRBMC)

Aleix Barberà RESCAT

www.centrederestauracio.gencat.cat/

RESCAT

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

PUBLISHER Departament de Cultura de la Generalitat de Catalunya EDITOR Àngels Solé EDITORIAL BOARD Esther Gual, M. Àngels Jorba, Josep Paret, Àngels Planell,

Pere Rovira, Mònica Salas, Àngels Solé and Maite Toneu GENERAL COORDINATION Àngels Planell TRANSLATION Josephine Watson PROOFREADING Àngels Planell, Maria Ferreiro, Josephine Watson

and Aleix Barberà TEXTS ©The authors 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. www.ciklic.com COVER Detail of the upper part of the The Roman Mosaic of the Sacrifice of Iphigenia

Key title: Rescat (Barcelona, Internet) Abridged title: Rescat (Barc., Internet)