An extinct variety of manganese blue paint is one of the many inextricable ingredients of Jackson Pollock’s 1948 masterpiece Number 1A, according to the authors of a paper published in the journal Proceedings of the National Academy of Sciences (PNAS). The nearly nine-foot-wide canvas, splattered with paint that evokes an expansive celestial atmosphere, is a mainstay in the teeming galleries of the Museum of Modern Art in New York.
Using a technique called Raman spectroscopy to study the molecular makeup of the painting’s pigment, the paper’s five authors—from Stanford University, City College of New York, and MoMA’s conservation department—identified manganese blue, a synthetic paint popular in the 20th century before being phased out in the 1990s due to environmental concerns related to its manufacture.
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“It’s really interesting to understand where some striking color comes from on a molecular level,” Stanford chemist Edward Solomon told the Associated Press. Artists use the striking color to which he referred; it is used as well in other applications, including coloring cement for swimming pools.
A description of the paper from PNAS distills the finding into intriguing if inscrutable terms: “Excited-state exchange interactions create multiple absorption features that filter nonblue light. This highlights the ability of molecular inorganic pigments to leverage ligand field effects to create multiple visible absorption features and lattice electrostatics to fine-tune the color.”
The discovery stands to help conservation efforts around a painting that will hopefully be the source of further study for a very long time. As MoMA conservation scientist Abed Haddad told Artnet News: “It offers insights into the development of the artist’s practice and to contextualize the work within the oeuvre and understand trends in the manufacture and use of certain colorants over time. This knowledge can be critical for developing effective strategies for display, since many pigments are sensitive to environmental factors such as intense light, ultraviolet radiation, and fluctuations in humidity.”