Too Much Salt

It was in November, almost 36 years ago when the wife and I traveled to Italy for our honeymoon. Our first four or so days were spent in the Eternal City, Rome. We visited the Vatican on at least two different days. On one occasion we were in the Vatican Museums, and had the opportunity to visit the Sistine Chapel. We had a tour guide for the museums and the Sistine Chapel. The Sistine Chapel is known for its Michelangelo ceiling frescoes (1508-1512) which had just completed a 10 year restoration. They were then to clean and restore the large wall fresco (1533-~1536), also by the master Michelangelo, titled the "Last Judgement". This large fresco sits behind the altar.

The Last Judgement is famous for its depiction of the second coming of Christ and the depiction of 300 souls, some tormented, some not. When we visited the Sistine Chapel art historians were aghast at the vibrancy of colors the restoration exposed. They claimed that Michelangelo never used such vibrant colors on the ceiling frescoes. It was quite the controversy, as hundred of years of candle wax, and human activity, had coated the great work and dulled the painting, leaving many to think that such colors were not apart of the original work, but done by the restorers. They seemed to want the candle wax and soot back, or at least some of it. Why do people think that in the 1th century everything had to be dark? It was part of the renaissance, after all. Overtime, that controversy has died down, and most have come to realize that the early 16th century masters had in fact used such vibrant colors. The Last Judgement, is mainly blue and skin tones due to the sky and the naked 300 persons portrayed. As the work gets closer to the floor it becomes darker, representative of hell. 

The Last Judgement Fresco
credit: Francisco Anzola
Source: Smarthistory.org

Fresco painting is a process where water-based pigments are applied directly onto wet lime plaster and as the plaster dries the pigments, by chemical reaction are bound to the plaster. It is intricate and exacting work with the plaster and timing being important. In his book Michelangelo and the Pope's Ceiling Ross King goes into the difficulties experienced in painting the ceiling by Michelangelo and his assistants. Ross also goes into the sourcing of pigments for the ceiling. For example, a monastery in Florence was known for its pigments, and King says "Their colors--their blues in particular--were the best and most sought after in Florence." (p66) Fresco creation is a difficult art form, and perhaps someday I will reread the King book and blog about this now rare art form. I have to say, I am not sure the world has seen again a genius like Michelangelo. His variety of forms is impressive painting, sculpture, frescoes, and architecture (he completed the design for the St Peter's Dome). 

This great work of art, within the Sistine Chapel, however, is now under attack by perspiration. The National Catholic Reporter had this to say:

"The lactic acid produced through perspiration binds very easily with the calcium present on the surface of the fresco," Fabio Morresi, head of the Vatican Museums' scientific research laboratory, told the National Catholic Reporter during a press visit to the Sistine Chapel Feb. 28. "That reaction forms a salt, calcium lactate, which creates a thin whitish layer on the surface. Over time, that layer mutes the colors and softens the contrasts of 'The Last Judgment.' "

The ceiling and other frescoes are cleaned during the night, which visitors do not see, using lifts, but The Last Judgement requires special scaffolding due to its location with the altar. 

Those 1990 art critics may be happy, but most wish to see the fresco as it was intended, and the nuance and contrast of colors can make a difference in how it is viewed. More people are entering the chapel than ever before. In 2024, for example, even before the 2025 Holy Year, the chapel had 6 million visitors, up from 1.5 million ten years earlier. Further, 2024 saw an average temperature in Rome being an amazing 4.5 degrees (F) higher than the average of 1991 to 2020. People come in hotter than before and their are more visitors. The church does not wish to be seen limiting visitors to one of the world's most important works of art, and that requires it to undertake more maintenance costs.

Pope Francis (non-posed photo) in Sistine Chapel
Contemplating The Last Judgement Fresco
Photo taken Christmas Day, 2014
National Geographic cover Aug 2015

The Last Judgement is being cleaned for the first time since 1994, This cleaning process, what the Vatican refers to as extraordinary maintenance, is not as extensive as the earlier restoration which removed centuries of soot and grime, this is removing that layer by removing the salt that adheres to the face of the fresco. The process is rather simple, dipping Japanese Vatican chief curator, Barbara Jatta refers to it like removing a cataract. The cleaning exposes more of the details of the great work of art. I suspect that is not a job I would want, as, if my wife is correct, I tend to be overzealous and would wipe away the fresco. The 1990's restoration removed the cloths that put in place to cover genital areas, and take it back to the original nudes Michelangelo painted. The cloths, or drapery, were put on after he died. 

Tourists at Vatican Museum Gallery of Maps
Nov 1990, photo by author

The restoration over 30 years ago countered the effects of much of the drapery installation of the Counter-reformation, but today a different challenge remains according the news reports: "today's intervention reflects a different challenge: safeguarding the fresco in an era of climate change and mass tourism." 

To help safeguard the priceless frescoes, climate within the Sistine Chapel is highly controlled. The temperature is kept at 71 to 75 degrees F, with a relative humidity of 55-60%. Most important, CO2 levels are at a level below that of a typical office building even though 700 to 800 persons will gather into the chapel at one point in time. Yet, as much as the Sistine is climate controlled, it can only do so much with perspiring people.

Google Map air photo of St Peter's Basilica and Sistine Chapel

The Vatican has a virtual tour of the Sistine Chapel which you can view here. My wife and I were fortunate to view the remarkable artwork in the Sistine Chapel in person. I recall most of our attention drawn to the then recently completed ceiling fresco restoration. At that point in time, since it was freshly cleaned, and the number of visitors was less, and the climate not has warm the colors were perhaps as vibrant when the ceiling was opened for viewing. 

What I learned from this is that too much salt is not just bad for the body, and our ecosystem, but also for the frescoes in the Sistine Chapel. Climate change is having a negative effect on the natural habitat (number of birds is way down) and cultural treasures.