varnish

Following five years of research using techniques such as digital imaging and artificial intelligence, eight restorers will begin "Operation Night Watch" by removing the varnish from the painting - in full view of the public, within the glass-enclosed space in The Night Watch Room.

The varnish, applied during a 1975-76 restoration, will be removed using microfibre cloths and cotton swabs.

And in 1990, a man sprayed acid on to the painting - although, this time, thanks to a guard's rapid intervention, only the varnish was damaged.

The artwork was coated with a dark varnish and accumulated dirt over the years, giving the false impression it depicts a night scene.

Its pieces, including the beer cans, are made of acrylic paint on aluminum and varnish, and could be found in unexpected corners at LAM.