Researchers study how to preserve glow-in-the-dark and fluorescent art from fading
US researchers have found that humidity is a major factor in the degradation of glow-in-the-dark phosphorescent pigments used in art, information that will help museums improve conservation practices. The research, which includes a collection of designer Stephen Sprouse's work, aims to support long-term preservation of such art and fashion pieces.
At an American Chemical Society (ACS) meeting, researchers presented findings on how fluorescent and glow-in-the-dark pigments used in art and fashion change over time. The work is led by photochemist Sarah Schmidtke Sobeck of The College of Wooster together with Gregory Smith, a conservation scientist at the Indianapolis Museum of Art, who have collaborated for the past decade.
The pair previously published a two-part study on the composition, spectral properties, and light stability of daylight fluorescent artists' pigments. That work found that the optical brightener compounds responsible for the vividness of fluorescent pigments degrade faster than the underlying dyes themselves, meaning colors can appear to darken even when the pigment itself hasn't broken down. This creates a challenge for conservators, who must match colors under both visible and UV light while accounting for the fact that the pigments continue to change subtly over time.
New research into phosphorescent pigments
In her talk, Sobeck described the team's newest work, which extends their research to phosphorescent, glow-in-the-dark pigments, with particular focus on the museum's collection of designer Stephen Sprouse's pieces. Early findings show that these materials differ markedly in composition from fluorescent colorants: rather than organic dyes, phosphorescent pigments rely on mineral-based pigments and inorganic compounds.
One notable discovery is that humidity plays as significant a role in the breakdown of phosphorescent pigments as prolonged light exposure — possibly even more so. This insight will help the museum refine how it stores and exhibits such artworks.
The project's next phase will focus on lithopone, a white pigment powder, examining how long phosphorescent materials containing it continue to glow after each exposure to light.
