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MICHELANGELO’S SISTINE CHAPEL CLEANED WITH AN OVEN CLEANER
How ironic that of the greatest single handed artistic achievements of our civilization was stripped clean by restorers for reasons of a miss guided analysis, using a soda reactant equivalent to an oven cleaner. This fracas is the result of a long awaited cataclysm between advances in restoration and technology conflicting with artists and their technique, ultimately facing the desensitizing of the human condition with industrialism and technology.
Had restorers conferred with artists on the Sistine Chapel this devastation might have been averted. Despite continued protests ‘Art Watch International’, an organization to watch dog against restoration abuses, sent a delegation headed by and James Beck, head of Art Watch, and Frank Mason, artist, to Rome to meet with the Vatican team of restorers, but nothing could be done. For centuries restorers have exercised the most extreme care to preserve and maintain intact Michelangelo's Sistine Ceiling. In the five hundred years since the creation of the ceiling, there has never been a period of more than ten years that some restorative measures have been performed on the Sistine Chapel be it small or a complete cleaning. Salts and mildew were constantly forming over the fresco and it was repeatedly brushed and washed off. Over the centuries there have been five major cleanings with over-paints, repairs and vanishings. The extended maintenance record of the fresco made it easy fodder for a simple fix for restorers with modern restoration technologies. In 1980, a team of restorers and art historians put together by and Vatican Director General of the Papal Monuments, Museums and Galleries, Carlo Pietrangeli; Dr. Fabrizio Mancinelli, Curator of the Department of Byzantine, Medieval and Modern Art of the Vatican Museums; Dr. Nazzareno Gabrielli, head of the Vatican Scientific Research Laboratory, responsible for all the technical analyses required during the work, and GianLuigi Colalucci, head restorer and Director for Conservation at the Vatican.
The restoration team had been using a product that is similar to EasyOff, an oven cleaner to clean frescos and decided to perform a twelve year heroic task of cleaning the ceiling. This soda reactant, a gelatinous solvent consisting of ammonium bicarbonate, sodium bicarbonate, Desogen, and carboxymethylcellulose; or AB 57 applied in a gel and left for three seconds then removed with distilled water, dried for 24 hours and was repeated again. The idea was to clean systematically from one side to the other retouching damaged areas with water color in the ‘vertical-stroke technique’ and then coat the entire ceiling with an acrylic resin of Paraloid B72 diluted to 3% solution in organic solvent. This powerful solvent is extremely astringent having left the surface course like sandpaper to the touch. AB-57 is irreversible. Simply stated, the scientific premise of the restoration team was that Michelangelo painted in 'buon fresco' and this solvent would clean off all the soot and grime accumulated over the ages from candles and incense smoke, dirt, dust and subsequent varnishes quoting countless sources throughout history that have labeled the ceiling as ‘dirty’ do to the soot. True fresco or ‘boun fresco’ is a chemical reaction of pigments applied on fresh lime, ‘intonaco’, that upon drying are fixed into the plaster, however, follow- up techniques including ‘a seco’ (dry painting over the fresco, tempera) or retouches, and glazes, ‘la velatura’ put on by the artist’s hand were also in limited degree accepted as part of the technique. AB57 indiscriminately removes any corrections, repairs, tonal unifications with glazing, returning the fresco to its initial state without any recourse for modifications and adjustments . Colalucci remains adamant that Michelangelo used only ‘boun fresco’ on the Sistina, although contradicting himself, he writes in “The Sistine Chapel “Michelangelo,s Colours Rediscovered” pg 261. “Technical and scientific research, concentrating primarily on an analysis of the pictorial technique, was undertaken on the ‘Eleazar and Matthan’ lunette. By the end of this investigation Michelangelo’s use of ‘boun fresco’ was unequivocally vindicated. He had worked in the purest Florentine tradition, using only colors suitable for fresco, avoiding any that would have required application ‘ a secco’. He had worked ‘a secco’ to a minimal degree, on the ceiling, but not at all in the lunettes, not even to carry out small alterations as he worked. Nor had he painted the colored or uncolored glazes containing binder, that some had taken to be not the result of a restoration, as in the fact they are, but the later, improvised corrections of Michelangelo himself.” Colalucci admits to some ‘a secco’ treatment on the ceiling. . It had been stated by Armannini, the Florentine color supplier, that ultramarine blue and gold was put on 'a secco' or glazed on later. These ‘a secco’ techniques were acceptable as 'buon fresco' at the time, having conferred with the most respected fresco painter in Florence, his compatriot, Giorgio Vasari that we know of from letters at the time. The problem persists in that this is a technological restoration backed by subjective technical suppositions and historical findings and not by understanding the artist’s objective of pictorial space and the limitations of the technique used. The most important element in this fresco is the passage of light throughout the ceiling. Restorers must be cognizant of the light effect without disturbing it from its totality to maintain the integrity. For this reason it is not possible to introduce a system of restoration that cleans equally across the board from corner to corner. Michelangelo’s narrative of the Judeo Christian era is built by transforming a barrel vault into an edifice on three levels. On the first level are the lunettes placed below a balustrade of pilasters and pendentives to support the coffers of the ceiling proper that depict the Biblical narratives. The light effect descends from the heavens into the apex of the ceiling, as it highlights the central motifs of ‘Creation of Man’, ‘Creation of Sun and Moon’ and ‘The Fall of Man’, which are then supported by the Prophets and Sibyls surround by pilasters and pendentives, followed by lunettes depicting the ‘Ancestors of Christ’ under an artificial impediment. A stylistic study of the light effect of the ceiling would have revealed that the dirty varnish layer was not even throughout its entirety. Some elements in the marble architecture were white without tarnish and others meant to be in shadow are much darker as if the soot had this kind of selective power . Artistically, the lunettes are in cast shadow from the pendentives which divides the sky plane from the ground plane, as the volt turns from the vertical plane into the horizontal plane and symbolically this separates the heavens from earth where the ‘ancestors’ depicted in the lunettes become part of the darkened past. The next level upwards are the prophets and sibyls which are in dramatic cross lighting projecting strong cast shadows to create three-dimensionality and make the transition into the final plane. As the effect ascends to the central narratives of Divine Power, they are in full light highlighting the power and glory of the central effect. The result from cleaning the ceiling across the board, in particular the removal of the shadow glaze from the lunettes makes the ancestors as prominent as the central figures because, the lunettes are on the vertical plane in frontal view and much closer to the viewer. The removal of this shadow glaze has destroyed the overall three-dimensionality of the work making it flat and artistically illegible. This brings us to the crux of this argument and how without an artistic understanding of the technique and materials used by the artist, by speculation the gravest travesty of art has willing occurred. To begin, the lunettes measured 3.4 meters high by 6.3 meters high, roughly 15 square meters as they are semicircles, and it took Michelangelo three days to complete a lunette, evidenced by the jointing in the plaster. They were completed freehand without cartoons suggesting that they are of lesser importance, knowing that they would later be subdued to the central effect. On the Roboam lunette there are no sutures visible suggesting he painted it in one continuous sitting. This calculates to painting five square meters a day (giornata) within 6 to 8 hours before the plaster dries, when the custom of fresco painters was to paint at best one square meter a day. How is it possible that Michelangelo painted ten times faster than Raphael? That is not to say that there was not tremendous rivalry between these two giants, to the extent that Michelangelo released his apprentices for fear they may reveal his secrets. This mystery can be resolved by Michelangelo use of a stylistic innovation to hasten his work, at the same time unifying his masterpiece in a focused effect. By reversing the methods of easel painting, Michelangelo created a system that was simple and revolutionary. In easel painting, the artist lays out an ink drawing, where in fresco, he pounces the cartoon onto the wet plaster. The difference is one draws a black and white image and shades the image, and when it is dry, glazes the local color on the corresponding forms, where essentially the color is painted last. However, Michelangelo shortcut this rule, because in ‘bon fresco’ shading and coloring have to be completed within eight hours before it dries, and the shading has to be done with crosshatching usually in an umbrian tone, as a common shadow in the different areas of color, and this was very time consuming. This new adaptation reversed the process, the color went on first. Michelangelo pounced the cartoon in the traditional manner to establish the drawing, and then painted in vivid colors filling in the shapes over an extreme area, within the allotted drying time, and without crosshatching. By using the core shadow line to juxtapose a light hue of brilliant color next to its complementary or contrasting darker hue in the shadow plane, knowing he could unify the form when dry by coating with a lampblack glaze, the notorious ‘ la liquisima velatura’ mentioned throughout history. For some clear examples of this core shadow juxtapositions; the red to yellow robe of Asa, Josaphat and Joram lunette or the violet to yellow compliment in the shirt of the Azor and Sadoc lunette. Michelangelo continued this juxtaposition on the core shadow of the anatomy as it turns throughout the fresco as an innovative way of avoiding crosshatching the shadows relying on the unifying lamp black glaze. The opposite of easel painting; the black and white underpainting was painted last. Notice the absence of crosshatching which is evident in fresco painting of this period. This divergence from the standard of fresco painting is what enabled Michelangelo to paint so swiftly because he by passed the burdensome problem of crosshatching to create shadow. Whether relying on a lampblack glaze for shadow and less on ‘boun fresco’, for reasons that Michelangelo was being pressured by Julius II to complete the fresco sooner or that the task was so overwhelming; he made a technical decision that would compromise his work and as fate would have it be its nemesis. A study was performed of the atmospheric patterns of the chapel to understand if pollution was affecting the surface and whether the soot from the lamps had been the cause of the blackened fresco. It was noted that some of the currents that circulating around the chapel effected the Fresco. The acidity of car pollution and particles of dust reached the surface, however, soot was too heavy and only reached four/fifths the height with not contaminating the surface (‘Study of micro climate of the Sistine Chapel’ by Prof. Dario Camuffo of the Instituto di Chimica e Tecnologia dei Radioelementi de Padua). This brings up the question of the black glaze that predominated over the ceiling or ‘la liquisima velatura. “This very dark, brown, glassy epidermis, consisting of layers of dust and fatty soot.” as quoted by Colalucci. This soot layer was tested by a Gas Chromatography-Mass Spectometry to identify fragments of molecules of organic material and results found it to be lampblack pigment suspended in protein or sizing. The final irony is that the process for making lampblack pigment which was used in the glue size glaze, is to take the soot from a lamp, wash it, and dry it to make lampblack pigment, which is what was interpreted as soot from years of burning lamps. This is important because the whole premise was that the soot on the surface came from the torches in lighting the chapel. This explains many loose ends as to why the glaze was darker in certain areas and not effecting others, like the white marble plaques mounted with the prophet’s names or gold spindles, the deep shadow covering the ‘ancestors’, also the lack of crosshatching, and the control over lighting his final effect.
Colalucci admits there are ‘a secco' overpaints and corrections of which there is evidence that he removed; fortunately there are extensive photographs of the ceiling before and after. With this restoration in place, at the beginning it was heralded by Roman newspapers as ‘Michelangelo the new colorist a Fauvist painter’ and there has been no stopping the deductions why Michelangelo painted in this embolden color scheme, however we as artists understand this is just the underpainting we are looking at. By Peter Arguimbau from an article published in the American Arts Quarterly, ‘The Sistine Chapel, Science vs. Art’ in the Spring of 1998. Arguimbau is an artist specializing in Old Master Techniques and was living in Italy for a period of three years during which the restoration was being performed. He was invited onto the scaffolding to witness the cleaning in 1984 with a restorer and colleague of Colalucci, Luciano Maranzi.

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