Mona Lisa replicas and reinterpretations
After restoration, the Prado's "Mona Lisa" revealed details covered by previous restorations and layers of varnish.
Furnishings and fabrics were enhanced, as well as landscape and facial features.
It is anticipated that such revelations may offer further insight into Leonardo's original.
Experts at the Louvre reportedly supported the Prado museum's findings.
The Prado replica was subsequently transported to the Louvre in 2012 to be displayed next to "Mona Lisa" as part of a temporary exhibition.
Two nude paintings bearing similarities to Leonardo da Vinci's original were part of a 2009 exhibition of artwork inspired by "Mona Lisa".
Displayed at the Museo Ideale in Leonardo's hometown of Vinci, near Florence, some believe one of the paintings – dating from Leonardo's time – to be the work of Leonardo himself, and it has at times been credited to him.
Other experts theorize the painting, one of at least six known to exist, may be just another copy painted by "followers" of Leonardo.
Scholarly dispute persists as to artist, subject and origin.
The nude in question, discovered behind a wall in a private library, reportedly belonged to an uncle of Napoleon Bonaparte, who owned another of Leonardo's paintings.
Facial features bear only vague resemblance, but landscape, compositional and technical details correspond to those of the "Mona Lisa" known worldwide today.
Mona Lisa's Revenge
The Mona Lisa tries to unleash a beast in the gallery basement, which she refers to as her brother. This creature is locked up in a vault and can only be released by using a puzzle box key. This key is destroyed by Harding who, despite his admiration for La Gioconda, cannot allow her to unleash the beast on the world. Luke, Clyde, and Rani have to try to solve the problem without Sarah Jane as she is now trapped in a painting. The Dark Rider captures Clyde and takes him to the vaults along with the Mona Lisa and Harding. As Mr Harding has destroyed the original key, Clyde is encouraged to draw another, that the Mona Lisa can bring to life as a replacement. This is done and the key is used, but before the beast can escape, a picture of K-9 drawn by Clyde also comes to life and fires at the beast, causing it to retreat into the vault. This sets off a chain reaction causing all the painting people to revert to being just works of art, and all those trapped in paintings to be released. The story ends with the Mona Lisa restored to her frame and Luke promising to tidy his room.Pearson Education published a simplified novelisation of this episode by Trevor Baxendale under the title "Painting Peril" for school literacy programs in September 2010.