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 replicas and reinterpretations
Leonardo da Vinci's "Mona Lisa" is one of the most recognizable and famous works of art in the world, and also one of the most replicated and reinterpreted. "Mona Lisa" replicas were already being painted during Leonardo's lifetime by his own students and contemporaries. Some are claimed to be the work of Leonardo himself, and remain disputed by scholars.
Prominent 20th-century artists such as Marcel Duchamp and Salvador Dalí have also produced derivative works, manipulating "Mona Lisa"'s image to suit their own aesthetic.
Replicating Renaissance masterpieces continues to be a way for aspiring artists to perfect their painting techniques and prove their skills.