The conservation-restoration of the frescoes of the Sistine Chapel was one of the most significant conservation-restorations of the 20th century.
The Sistine Chapel was built by Pope Sixtus IV within the Vatican immediately to the north of St. Peter's Basilica and completed in about 1481. Its walls were decorated by a number of Renaissance painters who were among the most highly regarded artists of late 15th century Italy, including Ghirlandaio, Perugino, and Botticelli. The Chapel was further enhanced under Pope Julius II by the painting of the ceiling by Michelangelo between 1508 and 1512 and by the painting of the Last Judgment, commissioned by Pope Clement VII and completed in 1541, again by Michelangelo.Massimo Giacometti, editor, The Sistine Chapel, (1986) Harmony Books, The tapestries on the lowest tier, today best known from the Raphael Cartoons (painted designs) of 1515–16, completed the ensemble.
Together the paintings make up the greatest pictorial scheme of the Renaissance. Individually, some of Michelangelo's paintings on the ceiling are among the most notable works of Western art ever created. The frescoes of the Sistine Chapel and in particular the ceiling and accompanying lunettes by Michelangelo have been subject to a number of restorations, the most recent taking place between 1980 and 1994. This most recent restoration had a profound effect on art lovers and historians, as colours and details that had not been seen for centuries were revealed. It has been claimed that as a result "Every book on Michelangelo will have to be rewritten".University of Victoria art scholar, John Osborne, in the Queen's Quarterly, as quoted in: Others, such as the art historian James Beck of ArtWatch International, have been extremely critical of the restoration, saying that the restorers have not realised the true intentions of the artist. This is the subject of continuing debate.
Previous restorations The frescoes on the ceiling of the Sistine Chapel had a number of interventions prior to the restoration process which was started in 1980. Initial problems with the ceiling appear to have been caused by water penetrating through the floor above. In about 1547 Paolo Giovio wrote that the ceiling was being damaged by saltpetre and cracks. The effect of saltpetre is to leave a white efflorescence. Gianluigi Colalucci, Head Restorer at the Laboratory for the Restoration of Paintings for Papal Monuments, Museums and Galleries, states in his essay Michelangelo's colours rediscovered, that the early conservators treated this cosmetically by an application of linseed or walnut oil which had the effect of making the crystalline deposit more transparent.
In 1625, a restoration was carried out by Simone Lagi, the "resident gilder", who wiped the ceiling with linen cloths and cleaned it by rubbing it with bread. He occasionally resorted to wetting the bread to remove the more stubborn accretions. His report states that the frescoes "were returned to their previous beauty without receiving any harm".Vatican Library, Vat. Capponiano 231, f 238 and Chigiano G. III 66. f 108. as cited by Colalucci Colalucci states that Lagi "almost certainly" applied layers of glue-varnish to revive the colours but does not state this in his report in the interests of "preserving the secrets of their [the restorers'] craft".
Between 1710 and 1713 a further restoration was carried out by the painter Annibale Mazzuoli and his son. They used sponges dipped in Greek wine which Colalucci suggests was necessitated by the accretion of grime caused by soot and dirt trapped in the oily deposits of the previous restoration. Mazzuoli then worked over the ceiling, according to Colalucci, strengthening the contrasts by overpainting details. They also repainted some areas the colours of which were lost because of the efflorescence of salts. Areas of repainting were hatched or treated with a linear brushstroke. Colalucci states that Mazzuoli also applied a great deal of glue varnish. The restoration concentrated on the ceiling and less attention was paid to the lunettes.
The penultimate restoration was undertaken by the Restoration Laboratory of the Vatican Museum between 1935 and 1938. The scope of the work was to consolidate some areas of the intonaco at the eastern end of the building and partially remove the soot and dirt.
Modern restoration
The preliminary experimentation for the modern restoration began in 1979. The restoration team comprised Gianluigi Colalucci, Maurizio Rossi, Piergiorgio Bonetti, and others, who took as their guidelines the Rules for restoration of works of art as established in 1978 by Carlo Pietrangeli, director of the Vatican's Laboratory for the Restoration of Pictures, which govern the procedure and methods employed in restoration. An important part of modern restoration procedure, as established by these rules, is the study and analysis of the artwork. Part of this was the recording of every stage of the restoration process. This was done by the photographer Takashi Okamura for Nippon Television Network Corporation.
Between June 1980 and October 1984 the first stage of restoration, the work upon Michelangelo's lunettes, was achieved. The focus of the work then transferred to the ceiling, which was completed in December 1989 and from there to the Last Judgment. The restoration was unveiled by Pope John Paul II on 8 April 1994. The final stage was the restoration of the wall frescoes, approved in 1994 and unveiled on 11 December 1999.
Aims of the conservators The aims of the conservators were as follows: To study the frescoes progressively, to analyse any discoveries and utilise the appropriate technical responses. To record every step of the operation in archival reports, photographs and film. To use only those procedures and materials which were simple, extensively tested, not harmful, and reversible. To repair cracks and structural damage that threatened the stability of the plaster. To remove layers of grime consisting of candle wax and soot that had been deposited by the burning of candles in the chapel for 500 years. To remove repainting by previous restorers that attempted to counteract the effects of soot and other accretions. To remove oil and animal fat used to counteract salination of areas where water had leaked through. To remove crystalline accretions of salt that had whitened areas where water had leaked through. To conserve surfaces that were in danger of further deterioration because of bubbling, and flaking. To restore sympathetically those areas where deterioration of one sort or another had obliterated details and caused loss of integrity to the whole, for example, filling a bad crack and painting the plaster in a colour matching the original. To maintain in small defined areas a physical historical record of the previous restorations that had taken place.
Preparation and approach
In 1979 Colalucci undertook a series of experiments to discover the right approach for the restoration of the frescoes of the Sistine Chapel. The investigation began by testing small areas of the wall fresco, Conflict over the Body of Moses by Matteo de Lecce, which had similar physical and chemical attributes to the painting techniques employed on Michelangelo's frescoes. Trials to find the right solvents were continued on a small portion of the Eleazar and Matthan lunette.
Because of the height of the ceiling and the inaccessibility of the ceiling frescoes, the precise nature of the damage and the problems that would be encountered by the restoration team could not be entirely foreseen until after the decision to restore was taken, and the scaffolding was in place. According to Colalucci, the continued scientific analysis and the response of the restorers to the particular problems was an ongoing part of the process, rather than the conservation team deciding on a single treatment for every part of the building.Gianluigi Colalucci's essay, Michelangelo's Colours Rediscovered in The Sistine Chapel, ed. Massimo Giacometti. (1986) Harmony Books,
In 1980, the decision to undertake a total restoration was taken. Nippon Television Network Corporation of Japan provided major funding of US$4.2 million in exchange for the exclusive reproduction rights.
Scaffold The team of restorers completed the first stage of the restoration, on the vertical surfaces and curved spandrels around the upper sections of the windows, from aluminium scaffolding projecting from just below the lunettes and using the same holes in the wall that had been made for Michelangelo's scaffold. When they moved to the ceiling, they likewise employed a system similar to Michelangelo's, which involved cantilevering a shelf outwards from the scaffolding to support a stepped and arched platform. The advantages of modern lightweight materials meant that the platform could be wheeled, facilitating easy movement along the length of the building rather than dismantling and replacement, as Michelangelo had done in 1506.Fabrizio Mancinelli's essay, Michelangelo at Work in The Sistine Chapel, ed. Massimo Giacometti, (1986) Harmony Books, Pietrangeli, Hirst and Colalucci, eds. The Sistine Chapel: A Glorious Restoration, (1994) Harry N Abrams,
State of the frescoes The findings of the investigation of 1979 were that the entire interior of the chapel, but particularly the ceiling, was covered with a grime of candle smoke comprising wax and soot (amorphous carbon). Above the windows (the main source of ventilation), the lunettes were particularly stained from the smoke and exhaust fumes of the city, being "much dirtier than the ceiling proper". The building was a little unstable and had already shifted considerably prior to Michelangelo's work of 1508, causing cracking of the ceiling, the crack in the "Judith" pendentive being so large that it had to be filled with bricks and mortar before painting. The upper part of the ceiling provided Michelangelo an irregular surface due to cracks and water seepage.John Shearman, essay The Chapel of Sixtus IV in The Sistine Chapel, ed. Massimo Giacometti, (1986) Harmony Books,
Continued ingress of water from the roof and from unroofed exterior walkways above the ceiling level had caused seepage which carried down salts from the building mortar and deposited them on the ceiling through evaporation. In places, this caused the surface of the frescoes to bubble and lift. Although discolouration was a serious problem, bubbling was not, because the thinness and transparency of the paint which Michelangelo employed on the greater part of the ceiling permitted the salts to pass through rather than accumulating beneath the surface.
Earlier restorations had all left their marks on the frescoes. To counteract the whitening caused by salination, animal fat and vegetable oil had been applied, which effectively made the salt crystals transparent, but left a sticky layer that accumulated dirt. An additional problem, most obvious in the small putti which hold the nameplates on the pendentives, was saltpetre seeping through small cracks and appearing as dark rings on the surface. Unlike the white crystalline salt deposits, this could not be removed and the staining was irreversible. Layers of varnish and glue had been applied to many areas. This had darkened and become opaque. Restorers had repainted details over the darkened areas in order to define the features of figures. This was particularly the case for the lunettes, spandrels and lower parts of the pendentives.