Every picture tells a story. But some pictures are keeping secrets or even telling lies. How can you tell if a picture really is what it seems?

Ask an art detective. These art conservators, restorers and curators rely on a sharp eye, a deft hand, a bit of sleuthing and a lot of chemistry to suss out the truth. They utilize a host of scientific methods and materials — from carbon dating and X-ray technology to UV lighting and chemical solvents — to solve a wide swath of mysteries, whether it’s attributing a work to the right artist or pinpointing the age of a painting or validating its authenticity (or lack thereof). In some cases, art detectives discover paintings hidden beneath other paintings.  

Take the case of the “Lost Princess,” featured in Traces: Revealing Secrets in Art and History at the William Rolland Gallery at California Lutheran University through Feb. 21. On exhibit are two images: one of an unremarkable painting of a woman and the other an extremely valuable portrait that was hiding beneath it. 

The painting belongs to the Carnegie Museum of Art in Pittsburgh, where experts thought something about it was “off” because the woman’s complexion and build were incongruous with her Renaissance dress. The museum deemed the portrait a fake and decided to get rid of it. But something about it nagged at the museum’s curator of fine arts, Louise Lippincott, who thought that the woman’s dress was spot-on for the period, even if her face wasn’t. 

Using X-ray technology on the painting, the art conservator Ellen Baxter discovered another face hiding beneath the woman’s visage. Using chemical solvents and a delicate touch, the painting of the woman’s face was removed to reveal a 16th-century portrait by Alessandro Allori of Isabella de’ Medici, a noblewoman known as the Princess of Florence.  

It is believed that in the middle of the 19th century, the owner of Isabella’s portrait altered it to reflect Victorian standards of beauty. With a stroke of a brush, gone were Isabella’s pale complexion and high forehead (which were de rigueur during the Renaissance). On the canvas were another woman’s sun-kissed skin, soft curls and a more slender face, hand and throat. Gone too was the urn that Isabella was holding and the faint halo above her head. (The urn, a symbol of Mary Magdalene, and the halo were used to suggest that Isabella was a pious woman. A futile gesture, for legend has it that the unfaithful Isabella was killed by her jealous husband.) The artist who painted over Isabella’s portrait left her original dress intact, unwittingly (or wittingly) leaving a clue to the painting’s true identity. 

Today, Isabella de’ Medici’s portrait is fully restored and infinitely more valuable than the painting that had covered it for hundreds of years. Needless to say, the Carnegie kept it and now guards it jealously.

It is often small, incongruous things that can tip off an art detective. “Sometimes you don’t need great technology,” explains Rachel Schmid, curator of Traces. “You just need a good eye.” 

Another case in point, also featured in the Traces exhibit, is the portrait of art dealer Earl Stendahl. One day, another art dealer named George Stern noticed that things about the portrait seemed off: A label had been scratched off, a piece of canvas was missing and, most curious, there was an official stamp of the Guy Rose Memorial Sale of 1926 on the back of the painting. Using infrared reflectography, another painting was discovered beneath Stendahl’s portrait. An art conservator painstakingly removed the painting of Stendahl to reveal “Rising Mists” by noted California Impressionist Guy Rose — a painting that had been lost for years.  

Discovering the truth about a work of art often begins with someone’s keen observation.

“The first step is to analyze it with your eyes and then we can continue to ask questions about it,” says Schmid. “The first question is, what do you want to know about a piece? What are you looking for? What information do you want to know, because there are so many different tests that can be performed on a work of art. It all depends on what answer you’re trying to achieve. Are you trying to decide if this is the correct artist? What time period it’s from? Is there another painting underneath?”

With all the scientific methods and technologies available, Schmid says, “You can tell a lot about a painting by its pigment.” Take white, for instance. For centuries, white paint was made with lead, which is now known to be toxic. Today, white paint is made with safer pigments. A clear sign of an artwork’s age is whether it was painted with lead-based or non-lead-based white paint. An art detective can often tell a painting’s age by shining a UV light on it because lead-based paint will fluoresce (glow) brightly.

Visitors to the Traces exhibit can get an art detective’s eye-view on several works of art. There are UV flashlights and safety glasses available to give visitors the opportunity to find evidence of hidden secrets in the artwork.

The exhibit is presented in partnership with CLU’s chemistry department and will be a focal point in the new Chemical Investigations of Art class, co-taught by Dr. Katharine Hoffmann and Robert Dion. “It will center around the questions a chemist can answer about a work of art,” says Hoffmann. Students will get the opportunity to perform some actual techniques used by art detectives to solve art mysteries. The rest of us can play art detective for the day, but it may change the way we look at art from now on.  

Traces: Revealing Secrets in Art and History through Feb. 21 at the William Rolland Gallery at California Lutheran University, 160 Overton Court, Thousand Oaks. For more information call 805-493-3697 or visit rollandgallery.callutheran.edu.