|Madonna of the Pinks at the National Gallery|
For example, this lovely work on the side is entitled Madonna of the Pinks. A renaissance-period work it was considered a copy of a Raphael and was sentenced to a century of obscurity in a castle far away in Northumberland. Then, while getting its 100-year cleaning someone noted its masterful execution and sent it to The National Gallery for a check-out. The gallery took out its electron microscope, infrared radiogram and mass spectometer to uncover the line drawings underneath.
Voila! Turns out that both the material of the line drawing and their style was doubtlessly characteristic of the great master Rapahel himself.
The painting now owned by the National Gallery and is currently on display at an exhibition Close Examination: Fakes, Mistakes and Recoveries. The exhibition displays more than 40 such paintings whose authorship was in dispute until super-sciences were used by the Gallery's laboratory to verify the claims and counterclaims.
Have you seen the Audrey Hepburn-starrer How To Steal A Million? It was the funnest film on fake art I've seen. Here's a trailer: