Charles Le Brun's painting of Everhard Jabach and His Family was finished in 1660. Now that it's 2015 and hanging in the Metropolitan Museum of Art, my favourite museum in New York, it was in need of a little bit of, um, reviving. The Met guides us through as it restores the giant piece of art and shows the steps the artwork needed to shine again.
It's explained all in the video below but the steps were pretty complicated and involved removing the varnish, laying the painting down, structural work, turning the painting over, re-stretching, varnishing the painting again, inpainting and spray varnishing the work. It's an involved process, but you can clearly tell the difference from beginning to end.