The Instituto Cultural Cabañas in Guadalajara has invited a team of professional restorers and conservationists to spend three months working on the 52 renowned fresco murals in its famous chapel. Completed in 1939 by Jose Clemente Orozco, the works are considered the best examples of the art movement known as Mexican Muralism.
Visitors will still be permitted to enter the chapel as the six white-suited specialists from Mexico City go about their business, although some of the frescoes may be off limits or obscured by scaffolding.
Alberto Gonzalez Vieyra, the team’s coordinator, described to me in encyclopedic detail the exacting process of fresco painting, an extremely durable technique that dates back at least as far as The Toreador painting on the island of Crete (1500 BC).
The process begins, he explained, with baking natural limestone (cal) in a kiln at a temperature of 1,000 degrees Centigrade to form calcium hydroxide, which is then mixed with water in an effervescent process, forming slake lime (cal apagada).
Fresco painting involves dissolving mineral pigments in water and applying them to a layer of slake lime on the wall while it is still damp.
“The pigment gets trapped in the stone and crystallizes,” said Gonzalez. “It actually becomes stone again, That’s the marvel of the process of fresco and what makes it so durable.”
But a finished fresco, though sturdy, is not invulnerable. “Constant humidity is a fresco’s enemy,” he noted.
To illustrate this, Gonzalez pointed at a scratch at waist level on one of the lower frescoes, probably made by a young person with something sharp. Nearby were some nearly invisible splatter marks.
“That’s something sweet, probably a soft drink,” he said.
The team can take a number of approaches with this type of damage. They can do dry, mechanical cleaning, try a sponge with an aqueous solution or even paint over the marred area. To be on the safe side, the new paint is removable and is done so that it can still be distinguished by experts from the original material.
Other types of damage might be in high areas of the murals, such as damage resulting from water and mineral seepage near the roof, or fungus, bacteria or insect infestations.
“Our team consists of artists, of course, but also biologists. And we are working with an architect too,” Gonzalez said.
The restorers are not just working on the inside of the chapel. On the day I visited, workers were also crawling around its stone exterior, apparently resealing the spaces between the large blocks from which the Cabañas is constructed.
The team, which includes one woman, comes from the prestigious Instituto Nacional de Bellas Artes in Mexico City, where they receive “diplomas and continuous training,” Gonzalez said with pride.