Several famous paintings are known to cover older works by the artist that can now be detected by scientific techniques like X-ray fluoroscopy, revealing the original paintings and drawings that would otherwise be lost to history. In other cases, works of art feature cryptic clues placed by the artist, or contain curious resemblances — and some have even sparked popular conspiracy theories.
Here are 16 hidden secrets in famous works of art.
The Sacrifice to Vesta
Goya’s signature on The Sacrifice to Vesta was uncovered by scientists using terahertz radiation. Though the 240-year-old work did not include a true documentation of authorship, the painting marked a turning point in Goya’s painting career. In May 2013, scientists at the University of Barcelona bounced terahertz waves off of the work and found a centuries-hidden signature beneath layers of paint on the bottom right hand corner.
Using infrared technology, scientists discovered a small self-portrait of Caravaggio hidden in his portrait of Bacchus . In 1922, there was speculation that another image had snuck into the image. At the time, it was said that this was the result of poor restoration, and the lack of technology meant that the debate ended then and there. Thankfully, the interest was seeded, and while it wasn’t until recently that scientists were able to use infrared reflectography to uncover a comical self-portrait of Caravaggio submersed in Bacchus’ wine, we’re already dreaming up the trailer for Honey, I Shrunk the Baroque Master .
The Blue Room by Pablo Picasso
The Blue Room is regarded as one of Pablo Picasso’s earliest masterpieces. It was painted when Picasso was 19 years old and living in Paris, and is one of the first works of his early “Blue Period” of melancholy scenes dominated by varying shades of blue.
In 2014, scientists announced that they had found a hidden image underneath the painted surface of “The Blue Room,” showing the hidden portrait of a man wearing a bow tie, resting his chin on his hand, reported the Associated Press.
It’s not yet known who the mystery man could be, but it’s definitely not a portrait of Picasso himself. One possibility is the art dealer Ambroise Vollard, who hosted Picasso’s first show in Paris in 1901.
Art historians say Picasso was poor but very productive at the time he painted “The Blue Room,” so it wasn’t unusual for him to reuse an earlier canvas for a new idea.