The Secrets Hidden on the Backs of Famous Artworks

To the untrained eye, it looked like just a piece of masking tape. But to Jeannette Redensek, a scholar reviewing hundreds of works in preparation for a comprehensive catalogue of paintings by German-American modernist Josef Albers, the yellowed strip of adhesive stuck on the back of one Albers work was a revelation.

The modest sliver of tape offered the final clue to determine the painting’s ownership history, and even where it had been displayed. “I knew [of another painting that] had absolutely belonged to this collector in Cleveland,” Redensek told Artsy. “On the back of that painting was a piece of masking tape onto which someone had written ‘living room.’ And so when I saw the masking tape on the other one that said ‘bedroom,’ I thought, that’s got to be it. It’s the same hand, it’s the same masking tape.” And she was right: The gentleman in Cleveland had owned both.

Redensek belongs to a distinct art world subculture—comprised of curators, conservators, researchers, and other market professionals who routinely flip paintings over—that has honed a connoisseurship of the backs of artworks that rivals the attention paid to the surfaces. “The verso of a painting can hold nearly as much information as the recto,” noted Katy Rogers, president of the Catalogue Raisonné Scholars Association and co-author of the catalogue raisonné of Robert Motherwell’s paintings and collages. Added Andrea Liguori, managing director of the Richard Diebenkorn Foundation: “Examining the back of a painting is nearly as important to us as examining the front.”

A painting’s face communicates its art historical context, but its reverse often carries the history of the artwork itself. On the backs of canvases, stretcher bars (the wooden framework holding the canvas in place), and the undersides of frames, careful examiners can often find inscriptions left by artists, last-ditch attempts to advocate for works once they’ve left the studio. Versos are also frequently marked by dealers, collectors, and museums, with notations ranging from greased pencil notes to wax seals, exhibition labels, and inventory numbers. Taken together, these markings are akin to a painting’s passport, representing its identity, travels, and even changes of address.

The artist’s notations usually serve as a means of ensuring that important information about a work—such as its title, date, and authorship—is preserved as it changes hands. But the practice is individual; some artists share more curious details or use both sides of a canvas. Artists who have continually reworked canvases may cross out bygone titles previously inscribed on stretchers, leaving hints about images cloaked beneath layers of superimposed brushstrokes.

“[The Metropolitan Museum of Art’s] portrait of Saint Philip Neri by Carlo Dolci has an inscription written by Dolci, in which he says when he began work on the piece, how long it took, and the fact that he started it on his birthday,” recalled Keith Christiansen, chairman of the European paintings department at the Metropolitan Museum of Art.

For 20th-century artists experimenting with abstraction, the backs of paintings were a convenient place to leave explanatory appendices. Richard Diebenkorn "often added arrows to his abstractions, sometimes in combination with ‘TOP’ in block letters, to dispel any confusion about a work’s proper orientation,” noted Liguori. And the Abstract Expressionist painter Motherwell sometimes left keys for deciphering multiple layers of meaning in a work’s title. On the back of a collage called The French Line (1960), which features a label from a box of French low-calorie breadsticks, Motherwell detailed every possible interpretation: “1. Painting (French) / 2. Diets (amis fidèles de votre ligne) / 3. Boats (trans Atlantic) / 4. Côte d’Azure (coast-line).”

Albers, who methodically experimented with color in his signature series “Homage to the Square,” recorded meticulous notes on the backs of more than 2,000 variations on the theme, produced over the course of 26 years. “He recorded both the name of the pigment and the name of the manufacturer,” Redensek said, grateful for these indexes that reliably differentiate between nearly identical works. “When I see the backs of those paintings, I can see that he’s changed out pigments to get a yellow ochre that’s a little darker, a yellow ochre that’s a little lighter, a cadmium yellow, a cadmium yellow light. He’s playing with very fine distinctions in the colors, and so those color notes are essential.”

Cindy Albertson, conservator of modern and contemporary paintings at the Philadelphia Museum of Art, has noticed that “[contemporary] artists, increasingly, are providing more information on the back of the artwork, which is sort of like a mini-artist interview.” On the back of a large Sean Scully painting she recently examined, The Fall (1983), the artist included assembly instructions: “This painting is top heavy so it is best to assemble it on its side. Then lay down (face up) and lift up—supporting the sides.”

What adorns a painting’s other side also differs between time periods. Older paintings with centuries of life experience wear pastiches of labels and stamps on their rears, prompting professionals specializing in different art movements to cultivate distinct expertises. “I will bet that the people in the Impressionist and modern [department], and definitely in contemporary, don’t spend nearly as much time as I have done in my career trawling through coats of arms to work out what noble family, from potentially anywhere in Europe, might have used an eagle, three stripes, and a crown on their coat of arms,” explained Jonquil O’Reilly, head of sales for the Old Masters department at Christie’s New York.

Aristocratic European collectors once embossed their paintings with wax seals bearing the family crest; canvas manufacturers would stamp their insignias on the raw material; and auction houses branded their lots with idiosyncratic alphanumeric configurations. Early 20th-century French art dealer Ambroise Vollard, for instance, typically inscribed his inventory with blue pencil. Art looted by the Nazis during World War II sometimes bears a series of stamps: one with the party’s emblematic double-headed eagle, another noting when it was seized, and others marking the checkpoints it crossed before reaching its destination.

“Just as you’re developing your eye looking at the [artists’ work],” O’Reilly added, “you also get a feel for all these different labels and collections that pop up now and again, and the different ways that people mark things.”

Understanding these markings is important to confirm a painting’s authenticity, or to increase its market value. When Robert Simon, a former co-owner of Leonardo da Vinci’s Salvator Mundi (ca. 1500), purchased the painting in 2005, he found an inventory number that identified it as part of the Sir Francis Cook Collection. “This was helpful because the head already looked very different from the image of the painting published [in a 1913 catalog],” noted Dianne Modestini, a conservation specialist and research professor at New York University’s Institute of Fine Arts who conserved the artwork, which recently broke records at auction, selling for $450 million. The Renaissance oil painting was repeatedly overpainted by restorers over the last few centuries, and reproductions of the work differ slightly over time. “[Simon] would have eventually identified it anyway, but [the inventory number] was immediately certain proof that it was the same painting.”