Art historical research continually uncovers new secrets. These include painted-over details, encrypted symbols, revolutionary working methods or even previously unknown details from the life of the artist himself. And of course, this is not to mention the countless theories and legends that surround many a work.

Technological advances have continually brought new insights. In recent years, the examination of paintings using X-ray machines in particular has allowed new insights into art; these naturally include works by great masters, as can be seen in a few selected examples:

(1) Artist: Jan van Eyck

Medieval painter Jan van Eyck’s masterpiece, the Ghent Altarpiece , contains one of the most famous “secrets” previously hidden under a layer of paint. The central panel of the altarpiece, also known as the Adoration of the Lamb , depicts a mystical lamb symbolising Christ, whose head has been reworked at least once – for example, to appear more “mystical” it had its eyes at the front of its skull (like a human, not an animal). However, this was later painted over with a “normal” sheep’s head.

(2)Professional secrecy

Many have wondered why Van Eyck suddenly changed his style to realistic representation. Contemporary theories include the use of lenses and curved mirrors, which made it easy to copy the image onto the painting surface. One such mirror can be found in the background of Van Eyck’s “Marriage of the Arnolfini”. Although many reject this theory on the grounds that it is an invention of the Renaissance, it is likely that such practices were already widespread during the artist’s lifetime, but were kept secret – as a professional secret.

(3) Artist: Michelangelo

Michelangelo Buonarroti, who described himself as a “sculptor, not a painter” of the Renaissance, gave art history several secrets to discover with his famous frescoes in the Sistine Chapel. Since some of the works were so high up that it was difficult to see any details, the artist allowed himself to include some not-so-subtle details.

It is now widely known that his depiction of God in the Creation of Adam, with his surrounding cloud of angels, closely resembles a cross-section of a brain. Since the Renaissance was also a time of anatomical research, many assume that the image was designed this way on purpose – although the interpretation of the context is still debated.

Another painting in the chapel depicts Pope Julius II as the prophet Zacharias with two angels, although Michelangelo famously disliked him. However, a closer look reveals that one of the angels is making a vulgar hand gesture (known as “the fig”) towards the Pope, which today would be comparable to the middle finger.

It is therefore not surprising that the figure in the wall fresco The Last Judgement , interpreted as Julius II, has to suffer in hell.

This fresco was also a painted-over work of art for a long time: Michelangelo painted all the figures completely naked – which was not well received by many of his contemporaries. During his lifetime, Daniele da Volterra was commissioned to add at least a minimum of clothing, which immediately earned him the nickname “braghettone” (“panty painter”). It was only during the last restoration that efforts were made to return it to its original state – a literal “revealing” that also revealed much lighter colors.

(4) Artist: Rembrandt

Rembrandt Van Rijn’s Night Watch is also affected by such a color change. The painting depicts one of Amsterdam’s riflemen’s guilds, but they do not patrol at night. Over the years, additional dirt caused the already dark painting to become a night scene, so that despite the darkness, the work should actually be called “Day Watch”.

Closer examination using the latest technology has also revealed a sketch underneath the painting that was later painted over. This supports several theories about this that were lacking proof until recently. However, it is not the only Rembrandt work that has been painted over; his Portrait of a Man also hides an unfinished painting under its layers of paint.

(5) Artist: Van Gogh

Of course, some “secrets” can be seen with the naked eye if you know what you are looking at. The “brain” in Michelangelo’s Last Judgement is not the only prominent example, although it is perhaps the most famous. Van Gogh’s Starry Night , for example, represents the principle of turbulent flow, according to researchers. This physical principle describes the random, varyingly large and rapid turbulence in the movement of fluids and is still an unsolved scientific problem, but the painting comes incredibly close to previous models.

As with most artists, there are also paintings by Van Gogh that have been overpainted – especially by Van Gogh, it should be said. Canvases were expensive and money was often tight, so the artist later painted over some of his student paintings with still lifes and landscapes. Later paintings were also overpainted: A dark portrait of a woman appeared under his grass background and Wild Vegetation was hidden under the ravine.

(6) Professional secrecy

Van Gogh enjoyed the benefits of the Industrial Revolution at the time: chemical research gave the art world around 20 new pigments, which are responsible for the bright colors of Van Gogh’s works. Unfortunately, the range of products available at the time consisted largely of toxic paints that contained substances such as lead, arsenic or mercury and were also sold as insecticides due to their effects. Today’s researchers do not think it unlikely that the paints were partly to blame for Van Gogh’s poor health.

(7) Artist: Leonardo da Vinci

Renaissance artist Leonardo da Vinci is also, perhaps more than any other, one of those whose paintings still hold mysteries for the art world. Studies of his Lady with an Ermine showed three different versions of the painting: one without an ermine, one with an ermine with grey fur and the last one with white fur. The animal was therefore added to the portrait later and would therefore have only been the “Portrait of a Lady”.

However, far more common than actual discoveries are the speculations and theories surrounding Leonardo’s works. For example, the positioning of certain elements in his Last Supper has been interpreted as the notes for a melancholic melody, but no other work has been the subject of more rumors and conspiracy theories than his Mona Lisa . Many have tried to extract secrets from the portrait, such as the reason for her “cryptic” smile or her missing eyebrows, but most of the speculations here are unlikely to fall into the realm of art historical research.

More historically relevant is the discovery of a “second” Mona Lisa , which is also said to be by Leonardo’s hand and is also older than the “original” in the Louvre. The work remained almost unknown until 2012, as it spent most of its time in private collections and was rarely exhibited. There is still debate as to the extent to which the Mona Lisa as such needs to be reconsidered.

(8) Artist: Caravaggio

Michelangelo Merisi da Caravaggio’s “Secret” is somewhat less theoretical. The painter, well known for his atmospheric paintings, created the Lute Player in two versions around 1595. The figure at the centre of both paintings was long interpreted as female. This went so far that the painting became known in Russia (where it has long been on display in the Hermitage in St Petersburg) as “Lyutanistka”, the “Lute Player Girl”.

Although many still consider the figure’s gender to be unknown, it is now widely accepted that it is a young man. Art historians have proven this with the figure’s visibly flat chest, as well as very similar depictions for which Caravaggio’s young friend Mario Minniti sat as a model, including Boy with a Basket of Fruit and Youth Bitten by a Lizard .

(9)Professional secrecy

The use of a camera obscura in baroque paintings is now widely known. Artists use a darkened room to transfer the image motif onto their canvas using a small opening or lens.

However, research has shown that Caravaggio’s paintings used light-sensitive materials. It is believed that a mixture of white paint and firefly powder was used to create a short-lived copy that could be seen in the dark and then transferred to a visible sketch – a kind of primordial photography.

(10) Artist: Vermeer

A well-hidden “secret” was also found in a work by the painter Jan Vermeer van Delft – a detail hidden under several layers of paint. His work Girl Reading a Letter at an Open Window originally featured the image of a naked Cupid in the background, which would have made the interpretation of the scene much clearer. The girl was clearly reading a love letter, while in the final version she could be reading the “emotional equivalent of a tax return.” Until now, the bare walls in Vermeer’s paintings have often been interpreted as an image of chastity; something that the subsequent change now refutes.

Art historical research in the spotlight in the coming years

These findings are only a small part of what can now be extracted from works of art using the latest technology. Constant technological progress also brings with it new examination methods and devices, which in turn reveal previously unknown secrets.

Current research methods are also far from being fully exploited. Many well-known paintings still need to be examined — for example, Rembrandt’s Blinding of Samson is currently being examined using X-ray analysis in Frankfurt.

Art historical research is therefore something that is definitely worth keeping an eye on in the coming years.

Interested?

Article for further reading:

Michelangelo’s “Creation of Adam” with a brain

Van Gogh’s “Starry Night” and Turbulent Currents

Van Gogh’s “Grasgrond” with a portrait of a woman

Leonardo da Vinci’s “Last Supper” with hidden musice

Leonardo da Vincis two „Mona Lisas”