Art 523, Issues in Art History
July 9, 2004
The Sistine Chapel Ceiling Restoration:
Destruction or Revelation
The eye does not see what the mind does not know
The following is an overview of the creation of the Sistine Chapel Ceiling frescoes by Michelangelo and their most recent restoration. In order to fully appreciate the significance of the restoration of the Ceiling and the controversy surrounding it, one ought to have an idea of what may have taken place in creating the ceiling frescoes. Did Michelangelo apply a fixative over the fresco or was it done latter by others? Did he change his style to incorporate more vibrant colors or did he intentionally darken them? These and other questions will be explored to gain a better understanding of the results of the restoration: destruction or revelation.
By 1504 and shortly after Julius II became the pope, the ceiling showed damage due to the shifting substrate under the chapel which caused the walls to bow out and the ceiling to crack. The chapel was closed, and Giulliano da Sangallo reinforced the ceiling and floor. Piermatteo d’ Amelia’s starry Heaven fresco was beyond repair, so in 1508 Michelangelo Buonarroti was commissioned to paint over the ceiling of the Sistine Chapel. On May 10, 1508 Michelangelo received a 500 ducat payment and began work on the ceiling.
Michelangelo may have had the approval of the Pope to do as he pleased in designing the ceiling, but at the time, approval was usually required of the haereticae provitatis inquisitor or master of sacred places. Rather than just paint over the starry Heaven, Michelangelo decided to remove the plaster and submitted 150 separate pictorial units and over 300 individual pictorials. His education was extensive enough to conceive the complex theological pictorials (King 61). Cartones or cartoons, large scale sketches that served as templates for the frescoes, were made after the pictorials were completed. It could have been that on seeing the sheer number of pictorials Pope Julius just waved him away and said ‘do as you please.’
The chapel was to remain open during the ceiling’s frescoing which meant the aisles had to be clear of all construction materials including the scaffold platform. The platform would be used in removing Piermatteo’s starry Heaven and subsequently by the painters. Michelangelo decided that the conventional platforms that were hung from ceilings would not work well and designed the platform in a style similar to an arched bridge.
Michelangelo had not worked in fresco in over 20 years so he chose his assistants wisely. Bastiano da Sangallo, Giuliano Bugiardine, Agnolo di Donnino and Jacopo del Tedesco were all accomplished fresco artists from the Florentine workshops of either Domenico Ghirlandaio or Cosime Rosselli (King 68). He chose his pigments from the friars of San Giusto alle Mura, famous for their vivid pigments, especially in azurite and ultramarine.
Rosselli and his workers built the scaffold designed by Michelangelo. They then proceeded to remove the 12,000 square feet of plaster in less than three months. Michelangelo began painting in October, 1508. Daily he would climb the 40 foot ladder to reach the top of the windows, the lowest point of the bridge scaffold, and then proceed up another 20 feet to the ceiling. The scaffold allowed enough space for five to six men to work upright (about seven feet). The removal of the plaster and the painting was done while standing – not on their backs as was incorrectly translated.
The ladder that led to the scaffold was near the walled masterpieces of Perugino, Ghirlandaio and Botticelli. These scenes were composed of brilliant pigments. “Ordinarily he [Michelangelo] had contempt for those who used great splashes of color in their paintings…acutely aware, however, that [viewers] would compare his own work to that of Perugino and his team, he seems to have made a compromise, using an abundance of ravishing color on the vault of the chapel” (King 122).
The first scene to be painted was The Flood, also known as The Deluge. Azure pigment, purchased from the Gesuati monks, was used for the waters. The only way to correct mistakes, called pentimenti or repentances, once the plaster was dried was with a hammer. For some unknown reason, The Flood scene underwent pentimenti by Michelangelo. The next problem with The Flood was mold and leeching salts. The salts resulted from improper mixture of the plaster, and mold was the result of painting on dry plaster as well as using adhesives to bind the paints to the plaster. Painting on dry plaster was sometimes done because it allowed for more vivid colors but this resulted in a short lived fresco and also mold would grow on the fresco. According to King, these results deterred Michelangelo from continuing this practice. Because of these mildew problems, Michelangelo worked almost exclusively in buon fresco style and rarely added secco touchups (128). Yet the controversy over the cleaning of the ceiling rests “on a single, simple point: did Michelangelo modify and embellish his frescoes after the application of the buon fresco layer with traditional secco media such as size or glue-based painting, or not?” (Beck 65).
Finally, after thirty-one giornate, or five to six weeks, The Flood was finished. Michelangelo then painted the two spandrels next to The Flood which each took eight days to complete. He transferred the image of the cartone for the first spandrel using spolvero for the whole image. For the second spandrel, he used spolvero only on the faces and painted the remainder on the intonaco in free hand using bright colors.
The lunettes near the spandrels were painted next. These he worked completely in free hand finishing the first spandrel in three days. He sketched the outline of the figures onto the intonaco and then painted them. He began frescoing Zechariah above the entrance six months after the start of the ceiling project. It has been said that Zechariah was painted in the likeness of Pope Julius, probably done reluctantly by Michelangelo as he was still upset about not being able to continue the work on the Pope’s tomb as he was originally commissioned to do (King 140).
The Drunkenness of Noah on the eastern side of the ceiling was completed next, and after the first year of frescoing, 4000 of the 12,000 square feet of the ceiling were complete. This included three prophets, eight ignudi (nudes), a pair of spandrels, four lunettes and two pendentives. This equated to about 200 giornates. “Far from portraying elegant groups engaged in polite and learned conversation, Michelangelo’s crowded scenes, such as The Battle of Cascina or The Flood, were always violent, every-man-for-himself struggles for survival, full straining limbs and wrenched torsos” (King 182).
The halfway mark on the ceiling’s frescoing came in the summer of 1510 after two full years of work. Pope Julius ordered that the ceiling be unveiled and available for viewing from the floor. Michelangelo conceded, probably because of the order, but also perhaps because of a personal desire to see his creation from an angle other than a few feet away. The unveiling was delayed when the Warrior Pope (Julius), at the age of 67, decided to go to battle to drive the French from Italy. Michelangelo believed he was due another 1000 ducats, so he followed after the Pope demanding payment. The Pope made good on the payment, and Michelangelo returned to Rome but no further work on the ceiling would be done until after the unveiling. It was a full year before the Pope finished warring and returned to Rome for the unveiling.
The unveiling took place on the Feast of Assumption, August 15, 1511 which was the 27th anniversary of when Julius, then the Archbishop of Avignon, consecrated the Sistine Chapel. The mass was well attended because everyone wanted to see Michelangelo’s work. Raphael, Michelangelo’s rival, was in the congregation for this event and “was, like everyone else in Rome, absolutely amazed by the ‘new and wonderful manner of painting’ that now became the talk of Rome” (King 231). Raphael even requested that he take over Michelangelo’s commission to complete the second half of the ceiling which was denied. At the time, Raphael was frescoing the Pope’s chambers, and he must have realized how few would view his work in these private rooms as compared to the crowds that would come through the Chapel.
Following the public showing of the first half of the ceiling at the mass, the scaffold that had been taken down was built again, this time under the western half of the ceiling. Painting resumed in October 1511, 14 months after completing the first half of the ceiling. On this second half, Michelangelo’s scenes were minimalistic, and he increased the size of the figures by about four feet, probably because after viewing the paintings from the floor he realized that the figures were difficult to see (King 241). The Creation of Adam was the first scene painted on the second half, and this took four giornate. The final Genesis scene painted on the ceiling was completed in one giornate compared to the six weeks it took to complete the first scene – The Flood.
The ceiling was finished toward the end of October 1512, four years and four weeks after Michelangelo had begun. Without fanfare he removed the scaffold and when the Pope and his cardinals went to vespers on the Eve of All Saints, they were astounded to see the Sistine Chapel’s ceiling in its entirety. Pope Julius only lived another three months dying on February 21, 1513. Michelangelo lived a long life dying just before his 89th birthday. The “new generation of Tuscan painters…made pilgrimages south to Rome…and then filled their works with the same luminous colors and sensual vigor that they saw on the vault of the Sistine Chapel” (King 312).
Numerous hazards affected the condition of the ceiling and ultimately were responsible for the restorations. These included, but were not limited to, a leaking roof; buckling walls causing cracks in the ceiling; an explosion in 1797 in the nearby Castel Saint ‘Angelo; smoke from burning incense and candles; smoke from ballot papers that were burned by the cardinals at the end of each Papal Conclave; Rome’s oil-fired central heat; auto emissions; water vapor from 17,000 daily visitors (400 kilos per day) (King 315); previous restorations; and “changing atmospheric conditions, which were causing contractions in the layers of glue that had been applied to the frescoes in previous centuries. The glue used to make the frescos more visible, had grown dark with grime” (Hirst Introduction).
Several restorations occurred over the centuries. They included:
Ø 1565, one year after Michelangelo’s death, Pope Pius IV ordered repairs to the foundation which caused significant cracks in the fresco. These cracks in the fresco were plastered and repainted, which included a significant portion of The Sacrifice of Noah.
Ø 1625 by Simone Laghi, who used linen rags and stale bread.
Ø 1700s by Annibale Mazzuoli, who used sponges and Greek wine and then applied a protective varnish.
Ø 1980-1989 by Gianluigi Colalucci, who removed the previous restorers’ secco refurbishments.
The Restoration: the Vatican’s and Supporters’ Perspective
According to Carlo Pietrangeli, General Director of Papal Museums, Monuments and Galleries, the restoration of the ceiling began by chance (Hirst Introduction). The cleaning of the fifteenth century frescoes on the chapel’s walls began in 1965 and was completed in 1974. The second phase of restoration began in 1980, and this was to include the frescoes on the entrance walls. Scaffolds were built that would allow the restorers to work on the wall paintings. “[T]he restorers were close enough to touch one of Michelangelo’s lunettes…they took the opportunity to clean a minute sample of the lunette…the success attained encouraged them to proceed…the result was truly astonishing. The original colors of Michelangelo’s painting, perfectly preserved under a thick layer of dust and glue, had reappeared” (Hirst Introduction). Patricia Corbett, managing editor of Retina, had similar thoughts when she wrote in 1982, “Despite some fear on the part of the Vatican authorities, the bold decision to restore the ceiling was made on short notice as an afterthought” (quoted in Beck 67). Thus began the controversial cleaning of the Sistine Chapel ceiling.
The chief restorer was Gianluigi Colalucci, and he was assisted by master restorers Bruno Baratti, Pier Giorgio Bonetti and Maurizio Rossi. Fabrizio Mancinelli was responsible for the scientific issues of the restoration and Professor Pasquale Rotondi the technical. The laboratory analysis work was overseen by Nazzareno Gabrielli and performed by the Office of Scientific Research of the Vatican Museums. Several studies were made of the ceiling’s surface prior to the cleaning and continued throughout the cleaning. These studies included observation with a stereomicroscope, with direct lighting, with raking light, infra-red light, with Wood light and reflectographs. Samples were taken for stratifigraphies, or color sections. The samples, observations, and analyses “determined that Michelangelo carried out the decoration of the ceiling and of the lunettes with the ‘buon fresco’ technique, that is abiding strictly by the basic rules of fresco painting as it is described in the treatises by Cennino Cennini and Giorgio Vasari….[C]orrections were done in three different ways: in ‘full fresco’ technique (replastering and repainting from scratch), in ‘half fresco’ (scraping off the plaster and the paint, applying with a brush a very thin layer of fresh plaster and repainting with colours diluted with water), or more rarely ‘a secco’ using tempera paints” (Papafava 77-78).
Art historians, critics and journalists attended a press conference on February 10, 1981 where the restoration was discussed and a timeline presented. The audience “warmly encouraged” continuing with the restoration of the ceiling (Hirst Introduction). The Vatican signed an agreement to have the restoration filmed by the Nippon Television Network Corporation. The agreement gave Nippon exclusive photographic rights for a period of three years following the completion of each stage of restoration. In return, filming of the restoration would be done free of charge.
Michelangelo’s fourteen lunettes, which cover 250 square yards, were restored between 1980 and 1984 along with other portraits. A second press conference was held at the completion of this stage of the restoration project and a warm welcome may not have been awaiting them this time. The critics were acknowledged by the Vatican but were considered just a small group compared with the supposed group of supporters. The second stage of the restoration began in November 1984 using a scaffold that was in the same style as what Michelangelo had used except this version had wheels and only covered a six foot section of the ceiling. During 1985, a conference was held to highlight the work to date. General Director Pietrangeli considered the conference “a huge success” because it was well attended by 1400 prominent Michelangelo scholars, art historians, critics and others. Little is said by Pietrangeli about the third press conference that was held in 1986 or the subsequent conferences, reports and books. The Samuel H. Kress Foundation of New York sent six master restorers to the Chapel in 1987 to examine the restored ceiling. Their report of the work completed to date was “entirely favorable” (Hirst Introduction). To the contrary, James Beck states, “Yet no comprehensive report on the restoration has ever been issued by the Vatican, and, perhaps even more indicatively, there has never been an open and free debate or open discussion among interested parties” (65). But a second international conference was held in 1990 at the Vatican, and “the most respected specialists in the field participated in a debate on numerous problems and issues raised by the restoration in progress” (Hirst Introduction). The Administrative Office of the Vatican State also gathered together an international committee to monitor the progress of the restoration but it is unclear if this group also monitored the work itself.
Over the course of the restoration, 15,000 photos were taken in black and white, slides and color. Nippon TV filmed the portions of the restoration, usually at the beginning of a stage or when told a significant event was to occur. They shot a total of 45,000 yards of 16mm film equating to 83 reels. Funding for a computer was donated by Baron Thyssen Bornemisza and was installed on the scaffold. Information was collected on the state of the frescoes, measurements and techniques used to produce the frescoes and on the restoration process itself.
Precautions and preservation measurements were implemented as a result of the data collected and other studies undertaken but no additives were applied to the fresco. The lighting in the chapel was changed to filtered light which is cooler. A new air handling system was installed to control and regulate humidity and temperature as well as filter the air. “The protection of Michelangelo’s frescoes after the restoration will no longer be left up to the application of substances of various natures, which inevitably, sooner or later, are destined to alter their composition, but to an accurate control of the microclimate of the Chapel” (Papafava 80). This is a good news/bad news statement. The good news is that the Vatican has decided to invest in the continued daily care of the frescoes. The bad news is they state that all restorative substances have and will alter the frescoes.
Pietrangeli points out that access to the scaffold bridge was available at all times to qualified individuals and that about 6000 took advantage of this invitation (Hirst Introduction). He does not define or go into detail on who might be included as qualified individuals other than to say critics, artists and well known personalities from the general public. He states that most visitors encouraged the continuation of the restoration but follows this with “[i]t is interesting to note, in contradiction to what might have been expected, the critics who disapproved have rarely and only rather hastily visited the bridge” (Hirst Introduction). One critic who claims to have been denied access to the scaffold is Venanzo Crocetti, a sculptor who 50 years earlier had been a restorer apprentice at the Vatican. At the time, as an apprentice, he thought the ceiling was in excellent condition and that the greasy soot strengthened the color (Beck 93). Beck holds Crocetti up as an expert opposed to the restoration but Crocetti’s statement, according to Beck, seems to have been made while Crocetti was a very young man and as an apprentice still learning his art form. The Vatican may have denied his request for access because he was not a qualified individual. Or it may have been because Crocetti wanted to observe the application of the solvent (Beck 94). “Of course, viewers had nothing to guide them, no background, no point of reference, and the entire spectacle was totally uninformative as regards to technical matters” (Beck 95). This flies in the face of the Vatican’s statement that qualified individuals were allowed access to the scaffold.
The full tone of these dazzling colors has only recently been rediscovered. Layers of unsaturated fat from five hundred years’ worth of candles and oil lamps, together with thick layers of glue and linseed-oil varnishes slathered across the fresco during multiple incompetent restorations, served to give the spandrels and lunettes such a somber and muddied appearance…Only when more expert conservation work undertaken by the Vatican in the 1980s stripped these layers of grime from the surface of the fresco did Michelangelo’s true colors reveal themselves (King 130).
The Restoration: the Critics’ Perspective
James Beck asks a few very basic questions in his book, Art Restoration: The Culture, the Business and the Scandal, such as why was the cleaning done in the first place; what actually happened during the cleaning vs. what was claimed to have happened; what will be the consequences of what was done; and what have we learned from the experience (67). The Vatican management claims there were cracks in the fresco because the glue had contracted due to fluctuations in the temperature and humidity (Hirst Introduction). At a conservation conference in 1987, Dr. Mancinelli reported, “it was the discovery of widespread flaking that led to the decision…to undertake the cleaning even though initial tests showed unequivocally that such cleaning would lead to a radical revision of the prevailing understanding of Michelangelo as a painter” (Beck 70).
Beck makes reference to several authorities’ beliefs that the Renaissance greats frequently retouched their frescoes in secco and then applied hot glues. He states that “[i]n simplest terms, he [Michelangelo] indeed painted a buon fresco. After the buon fresco dried, following an undetermined period of time, he prepared one or two layers of hot glue, which he applied to the entire painted surface and which permitted him to make the additions and modifications he desired” (503). Condivi, a friend of Michelangelo, discusses the final layer applied as l’ultima mano, applied over buon fresco (Beck 97). Frederick Hartt states, in response to Beck’s proposition that glues were normally applied to frescos, “[m]ore extensive understanding of fresco technique and closer attention to the sources would have shown Beck that glue was never applied by Renaissance painters as a covering for their frescoes, for obvious reasons. Glue darkens with some rapidity completely falsifying the original colors within about twenty years….Worse, glue tends to contract with time, pulling away flecks of painted intonaco….Undeterred by irrefutable contrary evidence, Beck maintains that the glue was applied by Michelangelo himself” (Hartt 508). Hartt goes on to state that there wasn’t enough time for the chunks of dust to accumulate under the glue if Michelangelo had applied the glue when the scaffold was in place (508). Papafava also states that the glues were applied during various periods on the entire ceiling to cover the salt deposits caused by the infiltration of rainwater and as a varnish to brighten the colors that had been dulled by soot and dirt (78).
The cost of cleaning the ceiling, which was sponsored by Nippon Television Corporation, is estimated at $3-$4.175 million (Beck 64). The compensation to Nippon was the copyright to all film, TV and still photography for a period of three years following completion of each agreed upon section. Nippon then published books and produced over 30 TV programs. James Beck was quoted a price of $300 per black and white photograph of the cleaned ceiling (64). The cleaning of the ceiling promised to be a very lucrative deal, initially for Nippon and subsequently for the Vatican.
According to Beck, the only way Michelangelo could have enhanced the shadows to give the impression of three dimensions was a secco (65). This was done with certain colors of paint to accomplish the 3-D effect after the plaster had dried, and it required a fixative. The restorers, with technical direction from Fabrizio Mancinelli and directed by master restorer Gianluigi Colalucci, and supporters believed the ceiling’s glue-paint was applied by later restorers. Critics believe Michelangelo applied the glue-paint and by removing it, his masterpiece has been altered and damaged beyond repair. “Since nothing can now be done to reverse this vast intervention [restoration], the reputations of the restorers, and their advisors and supporters, not to mention the Vatican itself, rest on their vindication of what was done” (Beck 65-66).
Beck states that his research into the prior cleanings reveals that only one documented major cleaning occurred during 1710-13 with no evidence of the use of glue paint or varnish (78). Vatican records were searched for expenses related to the ceiling, especially the cost of scaffolding which would have been used to work on the ceiling. At the time of publication of Beck’s book (1993), the only records found were for the cleaning in the 1700s with no mention of an expense for glue varnish. In 1990, Beck asked the Vatican restorers, “Does any documentary evidence exist to support the claim that hot animal glue was repeatedly applied to the frescoes [of Michelangelo] over the centuries in order to revive the colors? Colalucci conceded in reply that there was none” (76). Beck’s wording of the question is skillfully constructed, and if pressed to answer just the question as it was posed, would require a yes or no response only. Worded another way, is there documented evidence that only hot animal glue was used and was used repeatedly and was used over centuries and used only to revive colors? If any part of the question is no, then the only response available to the entire thing is no. Beck’s question seems to be stated in such a way as to gain the resulting answer that he desires to hear and to leave the reader with the impression that there is no evidence that glue was used in the previous cleaning. Thus by default, according to Beck’s reasoning, Michelangelo must have applied the glue.
“To determine the order of deposition of foreign matter, minute pigment samples are suspended in polyester resin. When it hardens, cross sections are cut and magnified. Dirt beneath varnishes suggests that they were applied much later than the pigment and not by Michelangelo” (Jeffery 698). “[T]he Sistine team showed that the glue was laid over the later metal clamps and over the restored cracks in the intonaco. I might add that the glue was also applied over the restorations to the Sacrifice of Noah carried out by
Domenico Carnevali between 1566 and 1571” (Hartt 508). This restoration is the one that took place shortly after Michelangelo’s death. It was done because work was performed on the chapel’s foundation which resulted in cracks in the ceiling and the fresco, especially The Sacrifice of Noah. Beck resorts to comments such as “[l]ack of historical verification may account for two features of the supporters’ campaign: a disparaging tone, and technically fanciful explanations” (91). He contends that secco additions and resulting glue could have been added months after Michelangelo completed the buon fresco. He would have used soot-producing light and heat during the four-year period while on the scaffold. This soot would be trapped under glue applied by Michelangelo (Beck 101). But the scaffold was in place for only three years. Two years up while frescoing the first half of the ceiling, one year down while waiting for Pope Julius to return from war and view the first half, and one year up to complete the second half of the ceiling in year four. Hartt speaks of the dirt under the glue as a “heavy crust” (509). “But the dirt which first settled on the fresco would have been incorporated into it by the process of carbonization (crystal-forming). On the other hand, any dirt settling after carbonization, and forming a discrete layer would have been penetrated by, and incorporated within, any glues applied by restorers” (Beck 113). It is unclear from Beck’s statement if he believes the glues were applied much later and if so, would be contradicting himself.
“Indifference to seemingly concrete evidence has been a common feature put forward by supporters” (Beck 84). Beck’s supposed concrete evidence is certainly circumstantial, at best and construed at worst. Case in point, Beck uses ‘evidence’ from Charles Heath Wilson, a painter who reported upon viewing the frescoes up close in 1876, “the frescoes extensively retouched with size colour, in the manner common, evidently by the hand of Michelangelo” (96). How can this be construed as evidence of an expert? Previously Beck is admonishing scaffold viewers for saying ‘it looks good to me’ without comprehending methodologies (96). The concrete evidence has come from the restorers scientific data but Beck has scoffed at this calling it “technically fanciful explanations” (91).
By the Vatican’s own publication, they state that restorative substances alter the ceiling. They make a stronger case than the critics that the glues were applied well after Michelangelo had completed the ceiling. Carbon dating of the animal glues, if done, was not mention in the materials I used but would be worth determining if the Vatican had performed it and what the results were.
Richard Serrin has said the ceiling now is analogous to ‘musac’ – a bland version of a well known song that is used to fill a void. Mr. Serrin presented more convincing evidence in his lecture than the authors used for this paper. He shows us what once was and now is. Seeing is believing.
So we go back to Beck’s question, “did Michelangelo modify and embellish his frescoes after the application of the buon fresco layer with traditional secco media such as size or glue-based painting, or not?” (65). Michelangelo was by all accounts a brilliant man and artist. Even though his art form was not frescoing, he surely knew the consequences of using a secco and the darkening characteristics of the fixative (animal glue) – the flaking and shortened life it would give to his paintings. He would have wanted his frescoes to last as long as his sculptures – forever. I believe he may have used a secco with animal glue to join the giornate. I don’t believe that he applied animal glue to the entire ceiling or even to great portions of the ceiling so that he could add shadows and depth. However, I do agree with the critics that the ceiling has been damaged by the restoration. It appears that the materials used for the cleaning have altered the colors Michelangelo intended all to see.
Arriccio: undercoat of fresh plaster put on first
Buon fresco: painting on wet plaster or intonaco
Contrapposto: image in the opposite or mirror image
Fresco: fresh or wet plaster
Giornate: an area of intonaco that was laid down and can be completed by the frescoist in a single day (giornata is a “day’s work”) (King 49)
Ignudi: nude youth
Intonaco: a layer of plaster made from lime and sand and spread over the arriccio that provides a permeable surface for pigments to be absorbed. This hardens and seals the paints into the masonry as it dries.
Lunettes: sections of the ceilings that contain the paintings of the Ancestors of Christ
Martellinatura: a technique where an old fresco is roughened with a Martello (pointed hammer) so that a new fresco can be painted over it and it will adhere
Pendentives: the frescoes in the four corners of the ceiling
Pentimenti: correcting mistakes with a hammer
Secco: painting on dry plaster by adding a fixture to the pigments. This method allows for a wider and brighter range of colors but it does flake and the colors change over time.
Sibyls: female soothsayers who dwell in sacred shrines and in fits of divine, trance-like madness, predict or prophesize the future using riddles. They prepare the pagan world for the coming of Christ.
Smaltino: pigment made from pulverized glass tinted with cobalt
Spandrels: sections of the ceilings that contain the paintings of the Ancestors of Christ. The corner spandrels contain the Miraculous Salvations of Israel
Spolvero: the technique of tapping charcoal from a porous bag along holes that outline the image drawn in a cartoon
Beck, James. “The Final Layer: ‘L’ultima mano’ on Michelangelo’s Sistine Ceiling”; Art Bulletin, volume 70, issue 3: September 1988, pages 502-503.
Beck, James and Daley, Michael. Art Restoration: The Culture, the Business and the Scandal; London: John Murray Publishers, Ltd., 1993.
Hartt, Frederick. “L’ultima mano on the Sistine Ceiling”; Art Bulletin, volume 71, issue 3: September 1989, pages 508-509.
Hirst, Michael. The Sistine Chapel: a Glorious Restoration; New York: Times Mirror Company, 1994.
Jeffery, David. “A Renaissance for Michelangelo”; National Geographic, volume 176, no. 6: December 1989, pages 688-713.
King, Ross. Michelangelo & the Pope’s Ceiling; New York: Walker & Company, 2003.
Papafava, Francesco. “The Cleaning of Michelangelo’s Frescoes in the Sistine Chapel”; Florence: SCALA, Instituto Fotographico Editoriale, 1992.