Carol Vogel tells the story behind the Met’s re-attribution of a Velázquez portrait of Phillip IV but the best part of the story is the Times’s interactive feature that allows one to see the restored and un-restored versions of the painting as well as listen to a discussion of the works and the Met’s case for the authenticity:

When the varnish and over-painting were removed for the first time, details in the composition emerged — the delicate hands, the strongly characterized head, the simple white collar, the elaborate gold chain, the draping of the clothes — that had the unmistakable characteristics of the artist.

“The way the light played on the collar: those few deft brushstrokes were identifying traits of Velázquez,” Mr. Christiansen said.

With more discoveries came more questions. X-rays showed that the same composition as the Met’s painting is buried beneath a slightly later full-length portrait of Philip in the Prado in Madrid. […]

The Met’s painting, they believe, is a signed replica of the original Prado picture.

“It was probably an official portrait done for someone associated with the court, since ministers and courtiers were expected to own official portraits of the king,” Mr. Christensen said, explaining that painters like Velázquez would often keep a template or a tracing of a composition like this so they could recycle it.

Reconsidered, a Met Velázquez is Vindicated (New York Times)