CHICAGO, Aug. 25, 2026 — Some of the world’s brightest colors don’t just reflect light, they create it. Scientists and museum conservators are now uncovering why these luminous pigments fade and how to preserve them for future generations. The findings could help protect artwork while informing the development of longer-lasting phosphorescent materials for a variety of applications, from fashion runways to airport runways.
The researchers will present their results at the fall meeting of the American Chemical Society (ACS) during the “Chemistry Behind Art and Art Conservation” symposium in McCormick Place. ACS Fall 2026 is being held August 23-27.
“Artists have always been attracted to bright, emissive colors. They allow you to do exciting things that you just can’t do with a regular pigment on the artist palette.” — Gregory Smith
Most paints and dyes are seen because they bounce visible light back to our eyes. Fluorescent and glow-in-the-dark pigments are different: They absorb light and give it back as a vivid glow. This produces the attention-grabbing visual effects found in pop art, fashion, traffic signage, and the glowing stars that many people stick to their bedroom ceilings as children.
Over time, however, these bright materials break down. And as the colors become duller, the artwork loses some of the oomph that was initially intended. “For artists, the effect isn’t simply cosmetic, because they intentionally use these colors for their visual impact,” says photochemist Sarah Schmidtke Sobeck, Professor of Chemistry and Dean for Faculty Development at The College of Wooster.
“Artists have always been attracted to bright, emissive colors,” says Gregory Smith, Senior Conservation Scientist at the Indianapolis Museum of Art at Newfields. “They allow you to do exciting things that you just can’t do with a regular pigment on the artist palette.”
And because fluorescent and phosphorescent materials attract attention and improve visibility, they’re also important parts of safety signs and markings. By understanding how these materials break down over time, Sobeck and Smith want to help manufacturers develop products that stay brighter longer, such as luminescent paint for airplane runways.
The duo has spent years studying daylight fluorescent and phosphorescent pigments through a collaboration that began 10 years ago when they met at a cultural heritage science conference in Maine. Their work initially centered on testing the emission of light from samples in the Indianapolis Museum of Art at Newfield’s Stephen Sprouse collection , which features fashion with bold fluorescent colors and attention-grabbing designs.
For Sobeck’s presentation at ACS Fall 2026, she will share new findings from her studies of glow-in-the-dark phosphorescent pigments. For this research, Sobeck and colleagues first identified what the materials are made of. Then, the researchers examined the pigments’ photophysics — how they absorb, store, and emit light — and how the processes change as the materials age.
The team found that many phosphorescent materials contain inorganic compounds and mineral-based pigments and differ significantly from the organic dyes commonly used in fluorescent colorants.
New studies on a white pigment powder called lithopone will add another dimension to the ACS presentation. Eleanor Fleming, an undergraduate chemistry major in Sobeck’s lab, will use photography to track how long phosphorescent materials containing lithopone continue to glow after being charged by visible light.
One of the most surprising initial findings is that prolonged exposure to high levels of humidity can play an equally important — and sometimes greater — role than prolonged exposure to ambient light in breaking down phosphorescent pigments. This information will “inform improved storage and exhibition conditions for artworks containing this pigment,” says Sobeck.
Earlier studies of fluorescent pigments from the Sobeck lab revealed that the compounds responsible for enhancing brightness, called optical brighteners, degrade faster than the pigmentary dyes themselves. As a result, colors appear to darken even when the pigment molecules remain intact. Wooster alumna Georgia Hopps-Weber, a double major in chemistry and art history, helped uncover these unexpected results.
These results also highlight why conserving modern artworks can be challenging. Conservators restoring fluorescent artworks must match colors under both visible and UV light, while the pigments themselves continue to change over time, making long-term restoration difficult.
The researchers also see their innovative collaboration as an opportunity to share with their students how chemistry combines with nearly any discipline.
“I’ve been able to establish a lot of different opportunities for students who are pursuing double majors in art history and chemistry, or chemistry students who are really interested in seeing how they can apply their studies to different real-world scenarios,” says Sobeck. “It shows how chemistry and art can come together to answer important questions.”
The research was funded by the Indianapolis Museum of Art at Newfields and the Hamburger Endowment for Collaborative Projects and Program Development at The College of Wooster. The DayGlo Color Corporation provided sets of pigments for analysis.
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Title
Glow in the light & dark: Investigations of the photochemistry of emissive pigments used in art
Abstract
Modern materials present unique challenges for art conservators due to limited studies of their properties and long-term stability. Synthetic chemistry has introduced a range of new dyes and pigments—originally developed for commercial and industrial applications—that have since found popularity in art. Daylight fluorescent materials, such as products manufactured by the Day-Glo Corporation, and glow-in-the-dark “phosphorescent” pigments begin to appear more prominently in art in the mid-20th century, though earlier pigments exhibit related emissive properties. This talk highlights ongoing studies into the chemical composition, spectral properties, and stability of these emissive artists’ materials. Our research focuses on how the unique photochemistry of these pigments influences viewer experience and informs considerations for museum exhibition and storage. Special attention is given to its relevance within the museum’s Stephen Sprouse Collection.