“I sometimes feel like a monkey in a zoo,” says Esther van Duijn, one of eight conservators restoring Rembrandt’s 1642 masterpiece “The Night Watch” in a glass chamber in Amsterdam’s Rijksmuseum, as the public looks on. “I’m mostly worried that I’ll drop my scalpel and everyone will see.”

Operation Night Watch — as the museum is promoting the process — is now in its sixth year and has just moved from the research phase to the beginning of the removal of the varnish added in the mid-1970s. The project is “putting our profession on the map”, says van Duijn. “We will reach a point when all the things we want to remove are removed and what you see is mostly Rembrandt, 400 years old. We try to work with the idea that the public has a right to see the painting. We have art so people can look at it.” But is she happy they are also looking at her? “No,” she smiles. “That’s something else.”

In the years since Rembrandt painted it, “The Night Watch” — which depicts a company of civic guardsmen and measures a monumental 363cm by 437cm — has become a national symbol for the Dutch. It’s impossible to overstate its significance to the Rijksmuseum. Not having it on view would be like the Louvre without the “Mona Lisa” or Oslo’s Munch Museum minus “The Scream”. It is a crowd-creator as much as a crowd-pleaser.