Restoration of the Sistine Chapel frescoes

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.

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.

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.

[7][11] 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).

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.

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.

Retouching and repainting that had been part of previous later restorations were removed with a gelatinous solvent, applied in several stages for measured times, and washed with distilled water.

Once the many layers of candle wax, varnish, and animal glue were removed from the surface of the Sistine Chapel frescoes, they became subject to dangers that could not have been predicted by previous restorers.

One of the major dangers to the frescoes is automotive exhaust, and they are also vulnerable to the effects of the crowds of tourists that pass through the chapel every day, bringing with them heat, humidity, dust and bacteria (the latter of which can biodegrade paints and pigments).

It has been designed to counteract the various problems specific to the Chapel, in particular the rapid changes of heat and humidity that occur with the admission of the first crowds of tourists each morning and the departure of the last visitors each afternoon.

The air conditioning varies not only the heat but also the relative humidity between the summer and winter months so that changes to the atmospheric environment occur gradually.

One of the most vocal of these critics was James Beck, of ArtWatch International, who issued repeated warnings about the possibility of damage to Michelangelo's work from over-strenuous restoration.

How many times can people go through one without their poor faces looking like an orange peel?While James Beck became "embroiled in a public debate" with Gianluigi Colalucci, Ronald Feldman, a New York art dealer, started a petition supported by 15 well-known artists including Robert Motherwell, George Segal, Robert Rauschenberg, Christo and Andy Warhol asking Pope John Paul II to call a halt to the procedure and also the restoration of Leonardo da Vinci's Last Supper.

[17] An undertaking of the restoration team was that everything would be handled in a transparent fashion, that reporters, art historians and others with a bona fide interest should have ready access to information and to view the work.

Andrew Wordsworth of The Independent, London, expressed the major point of concern: There seems little doubt that the ceiling of the Sistine Chapel was in part painted a secco (that is, once the plaster was dry), but the restorers none the less decided that radical cleaning was necessary, given the amount of dirt that had accumulated (in particular from candle smoke).

As a result the ceiling now has a curiously washed-out look, with pretty but flavourless colouring – an effect quite unlike that of Michelangelo's intensely sensual sculpture.This crucial matter was also emphasised by Beck and defined in very clearly expressed terms on the website of the artist, Peter Layne Arguimbau.

Contrary to this view, James Beck and numerous artists have suggested that Michelangelo used carbon black in a wash of glue to lay on shadows and crisp dark definition, a secco.

[22] Critics of the restoration claim that this was Michelangelo's aim and that many frescoes had brightly contrasting colours laid side-by-side that were then worked over a secco to achieve this effect and that this is what has been lost by a too-scrupulous cleaning.

[21] Consistently missing from the restored ceiling is the crisp a secco detailing of the architecture: the scallop shells, acorns and "bead and reel" ornament which Michelangelo possibly would have left for completion by an assistant, when he moved on to the next panel.

The curator, Fabrizio Mancinelli, quotes the 18th-century French traveller De Lalande in saying that the colouring of the ceiling was, by that time, monotonous, "tend[ing] towards dull red and grey".

[7] He goes on to say that perceptive viewers of the Sistine Chapel ceiling have always been aware that the range of colours used was very different from that which could be seen,[25] and included the same pinks, apple greens, oranges, yellows and pale blues that were employed by Michelangelo's teacher, Domenico Ghirlandaio, one of the most competent fresco painters of the Renaissance.

The brilliant palette ought to have been expected by the restorers as the same range of colours appears in the works of Giotto, Masaccio and Masolino, Fra Angelico and Piero della Francesca, as well as Ghirlandaio himself and later fresco painters such as Annibale Carracci and Tiepolo.

The reason for employing this range of colours is that many other pigments are not usable in fresco as they have chemical properties that react badly in interaction with wet plaster.

These colour combinations, which are best described as iridescent, can be found at various places on the ceiling, including the hose of the young man in the Mathan lunette which is pale green and reddish purple.

[f] There is absolutely no doubt that before the restoration, the whole ceiling was dirtier, more muted and more monochrome than Michelangelo ever intended, but when images of the frescoes are viewed in their stained and unrestored state the subtle washes and intense definitions, described by Beck and Arguimbau,[21][22] still make their presence known, giving mass and bulk to the forms.

All the other, less intense, black lines and washes have been removed, lessening the impact of the radical foreshortening, and also robbing the great fish, the genii behind Jonah, and the architectural figures of much detail.

[sic] Proof of one single change of the artist's intent is negligence of which there are many.Richard Serrin, in an essay entitled Lies and Misdemeanors: Gianluigi Colalucci's Sistine Chapel Revisited says: The [so-called] Glorious Restoration of Michelangelo's frescoes has destroyed them forever.

The ceiling has proved a veritable beacon for our art, of inestimable benefit to all painters, restoring light to a world that for centuries had been plunged into darkness.

Pietrangeli made acknowledgement that these people spurred the team on to punctilious documentation so that a full report of criteria and methods should be available to those who are interested, both in the present and the future.