Archaeological Conservation Institute, Italy 2011: an educational field experience for future

Luogo dell'intervento: 
Convento di San Nicola, Belmonte in Sabina

In May 2011 ten undergraduate and graduate students (Galya Bacheva, Rhiannon Knol, Monica Varner, Via Baker, Gage Stuntz, Lindsay Wood, Angelina Collins, Cathy DeSilvey, Shannon Burden, Tierney Dickinson) from a variety of disciplines participated in an intensive two-week long Archaeological Conservation Institute at the laboratories of the Centro di Conservazione Archeologica (CCA) of Rome in the restored13th century Convento di San Nicola near Rieti in central Italy. The Institute, which grew out of a coincidence of interests of Roberto Nardi (CCA’s director) and Susan Stevens (Professor of Classics and archaeology, Randolph College), was designed with two complementing goals.

The first was to introduce the principles of conservation of cultural heritage through lecture-discussion sessions and study trips that put the lessons of the Institute into a broader context, including visits to Hadrian’s Villa, Perugia, Assisi, Spoleto and a weekend in Rome. Students also experienced the living cultural heritage (local produce, cooking, olive oil and wine production) of Sabina, where the Convent is located, once the native land of the Roman emperor Vespasian.

The second goal was to focus on archaeological conservation of the Roman Mediterranean through site visits, lectures, and hands-on experience with ancient artifacts, materials and technology. Guided by the CCA’s conservators, students participated in an ongoing conservation program by helping to clean, stabilize and reassemble the fragments of a frescoed apse and an opus sectile (cut marble) floor from the 1st-2nd century AD Roman villa of Sant’Imbenia in Sardinia. The two-year conservation program will return these artifacts, removed from the site during the1999-2005 excavations of the villa, as a multi-media installation in the Museum of Alghero.

At the conclusion of the Institute the students reflected on the message of the Institute and its impact on their thinking, excerpted in the following paragraphs.

• A broad understanding of conservation makes it an essential component of every phase of the archaeological process, not an end-product like reconstruction or restoration. Preventive conservation, in particular, means taking action that could protect an object or monument, as opposed to action taken after damage or decay has already occurred. It includes simple and immediate strategies such as proper cleaning and storage of artifacts, and the backfilling of archaeological sites, as well as long-term planning for regular programs of monument maintenance, the development of emergency plans, and legal protections against looting and vandalism. Since conservation plays such a crucial role in an object’s or monument’s life, professionals must, through open communication with the public, create an awareness of the fragility of artifacts and monuments.

• Conservation is “a wonderful duty to receive and to transmit” the message of cultural heritage. As specialists, conservators have privileged but not secret access since communicating the process of conservation is a vital part of any conservation project. Rather than a methodology, communication is an attitude based on openness, generosity, and inclusiveness. In 2001, during the conservation of the black Centaurs from Hadrian’s Villa at Tivoli, the gallery in the Capitoline Museums remained open to visitors who were invited to interact with conservators working on the statues from a raised floor.

 The project, an expression of an ethos of openness, was called “Aperto per Restauro”(Open for Restoration), an antidote to the signs posted all over Rome announcing the closure of sites for restoration. This and other open worksites have proved beneficial as a way for all to appreciate the beauty and fragility of cultural heritage and the effort required to preserve it. Thus, conservation is not just the technical work of stopping degradation at a material level but, through encouraging public awareness and enthusiasm, helping to ensure the appreciation and safety of cultural heritage for years to come.

• While the diffusion of information about archaeology, art and conservation can be difficult to convey to a general public that has little time, awareness or specific interest, involving children in conservation by feeding their curiosity about the world around them both builds a bridge to their parents and other adults and establishes a foundation for their and future generations’ involvement with cultural heritage. Instead of cleaning and restoring sculpture at the Capitoline Museums in Rome behind closed doors, the CCA involved children at its open worksite, encouraging them to interact with conservators and learn about the sculpture’s history and conservation. Children engaged directly with the sculpture by photographing and drawing it and were invited to participate in story and poster contests, motivating them to learn by experience. The power of childhood exposure to and active participation in conservation is reflected in the fact that one of those contest winners is today studying to be a conservator.

• Conservators have a threefold responsibility, to discover and record new information about the past, to present their work to the contemporary public, and to provide invaluable information for future conservation. The respect for the monument that must be their primary concern is best demonstrated in the careful recording not just of original elements, but also the work of past conservators. The detailed documentation of the apse mosaic of theTransfiguration in the church at Saint Catherine’s Monastery (Sinai) included a complete record of surviving original tesserae, past restorations and the few modern glass replacement tesserae (tiles). An essential tool for future conservation, this documentation is equally important for validating the authenticity and heightening appreciation of the long history of this priceless creation of cultural heritage, still in use in its original context. One of the most exciting results of documentation during conservation is the knowledge it can contribute about the material or life and use of a monument, which may otherwise have remained unknown. At St. Catherine’s, for example, the conservation team determined that gold glass background tesserae of the mosaic were regularly set at the same deliberate angle to the surface rather than being laid flat.

• High resolution digital photography is an essential tool to document archaeological conservation because of its speed, accuracy and flexibility. Digital photographs with corresponding computer software can map and analyze different aspects (its surviving original surface, surface damage from water, pollution, plants and modern restoration) of a monument in separate color-coded layers. Assembled, the layers represent a monument’s history graphically. This technique, used during the conservation of the mosaic of the Transfiguration at St. Catherine’s, produced a more complete and detailed documentary record than had been possible before the advent of high resolution digital photographs and the sophisticated software, fast processing speeds and high-capacity storage of late generation computers. A striking added benefit of the digital photograph at St. Catherine’s, printed at 1:1 and applied to the underside of the scaffold on which the conservators were working, was that the image was practically indistinguishable from the mosaic original. The life of the church went on with comparatively little disruption over the five years of the conservation program.

• Conservators repeatedly face artefacts permanently damaged by previous conservation efforts. Iron pins rust in walls and statues, eventually doing more harm than good. Abrasive materials and chemicals corrode the surfaces of frescos and mosaics that they were supposed to clean and preserve. Low impact conservation focuses on achieving results through slower, natural, non-invasive, and reversible conservation techniques. Cleaning frescos with water and brushes, for example, can remove most dirt, ensuring that as few chemicals as possible interact with delicate surfaces. Stubborn deposits of dirt and calcification on statues can be effectively loosened by an atomizer delivering a gentle spray of one part water to four-hundred parts air. Flour-based glue that can be used in moving and conserving mosaics is a natural and low-cost adhesive, easily removed with steam. These are simple strategies that allow conservators to preserve objects of cultural heritage for longer periods of time, lessening the effects of modern conservation on ancient materials.

• To clean fresco fragments is to participate in the transformation of what seemed to be amorphous lumps of plaster into recognizable pieces of paintings with their original bright colors and vibrant artistry. Deposits of dried mud and calcium carbonate are removed through a simple and non-invasive process of mechanical cleaning in two stages. In dry cleaning, a stiff brush is used to remove dirt from the back of fragments, a soft toothbrush for the fragile edges essential for finding the joins between fragments, and a soft paintbrush for the surface to avoid removing pigment. In wet cleaning the back and edges of fragments are sprayed with a mixture of distilled water and antimicrobial solution to prevent organic growth, and gently brushed with a toothbrush. Dampened layers of tissue left on the surface loosen remaining dirt deposits that can usually be cleaned off by gently rolling a cotton swab across the surface. Thick deposits of dirt still adhering to the surface can be removed carefully layer by layer with a scalpel. Cleaning by a chemical treatment, though sometimes necessary, is always a last resort.

• How do conservators piece together the fresco of an artist who lived centuries ago from thousands of excavated fragments? Surprisingly, not by relying on artistic insight but with logic and acute attention to detail. After cleaning and grouping fragments by pattern and palette, the first step is to become familiar with the groups, noting variations in shade and size of overall designs. In the next step, conservators look methodically for joins by focusing on the distinctive features of a single fragment, its curvature, the thickness of the paint, its brushstrokes, environmental damage to the paint, and the color and amount of mortar underlying the surface. They identify which features are close enough to the edge to affect adjoining fragments and by visualizing the extension of the fragment’s edges they improve their chances of seeing associated fragments. By focusing on the directionality of brushstrokes the probability of finding a join is significantly increased. By contrast, since the surface edges of fragments are accidental and susceptible to breakage, finding joins by comparing surface edges is less reliable than by comparing intrinsic characteristics of the paint. By following a process of isolating the factors that distinguish each fragment, conservators gradually reduce the number of possible adjoining fragments to five or six which can be tested to find the correct joins.

• Most museums have certain things in common that they share with hospitals, white walls, bright lighting, various rooms, and corridors. As a museum visitor it is often too easy to walk past exhibits in which everyday objects from our cultural past have become works of art, priceless and untouchable, devoid of context, placed on pedestals, encased in glass. Rather than feeling alienated by an object’s protective environment, visitors need a context for objects that connects with them. If they cannot “visualize” the connection, visitors miss the message of the object and each time this happens, a culture’s heritage erodes. Context, as well as objects, must be conserved and building a compelling and stable context takes planning, research, and some creativity. An outstanding example of an installation that retained the context in which objects were found, thereby clearly transmitting their messages, was the guided tour of the late Roman house beneath the glass floors of the Palazzo Valentini in Rome, in which actual elements were enhanced by real-time virtual reconstructions.