DENVER — During the fire at Notre Dame Cathedral, policemen and other city leaders formed a human chain to save artwork from inside the building, according to Paris Mayor Anne Hidalgo.

Many of the precious pieces have since been moved to safe locations within the Louvre Museum. It is still unclear how much charring, smoke damage and water damage they may have from the fire.

“I feel pretty confident that stained glass — as an example — will be able to be recovered. Metal sculptures very likely, stone sculptures it’s anyone’s guess what degree the soot can be extracted, particularly if parts of the stone are porous at this point,” said Sarah Melching, Silber Director of Conservation at the Denver Art Museum.

At DAM, a team of specialists called conservators perform the delicate work of preservation and restoration of art in the museum’s collection.

“Part of what we do is a restoration. So if there’s a loss to, say, a painting that was water damaged and some of the image material went away, then we would stabilize it first and then, in conversation with the curator, decide to what level we would restore that missing area,” Melching said.

The conservation team is made up of individuals with training in chemistry, art history and studio art. They are experts at performing chemical tests and procedures, matching colors and performing intricate maneuvers on works of art.

Those are the same skills conservators in Paris will employ when beginning the restoration process of the works from Notre Dame.

According to Melching, the next few days are critical in the preservation of the art that has been saved from the cathedral.

“Within 72 hours, that’s when mold can start to form and that’s kind of a crucial time frame that you want to address for things that are particularly water damaged,” Melching said.

Books, papers and photographs can sometimes be saved from mold by wrapping and freeze-drying the items. According to Melching, conservators may also place items under vacuum to extract moisture.

Soot and smoke will likely be the other big problems facing French conservators.

“There are various kind of chemicals that we can use to clean surfaces,” Melching said.

Some works may simply require clean water and soft cloths. Others may require further bleaching to remove stains. They can also employ a dry cleaning method using a soot sponge, which is similar to a dense cosmetic sponge.

“I think the outcomes will be mostly positive,” Melching said.

It is too early to estimate how long restoration of the Notre Dame artworks may take. Some pieces with little damage could be finished within a few weeks. Others may take substantially longer.

“These are long-term efforts,” Melching said. “I remember when the library in Leningrad burned in 1987. Recovery efforts are still ongoing.”

More information about art recovery efforts can be found here.