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Oxidation Paintings

Wide, landscape-oriented painting on a gallery wall, protected by stanchions.

Andy Warhol's Oxidation (1978) hanging in the museum's 5th floor gallery. When more hands-on conservation begins, the painting will be relocated to a smaller gallery where visitors can watch as work progresses.

In the summer of 2020, fluctuations in gallery climate triggered a chemical reaction in this painting that visibly changed its appearance. It’s a development that prompted a deceptively simple question: What happened? Thanks to a generous grant from the Bank of America Art Conservation Project, museum staff are hard at work finding answers. The examination and analysis of the Oxidation paintings in our collection will contribute to proper stewardship, preservation, and treatment of the nearly 100 other works worldwide.

Watch: Origins of the Project

Museum staff including Amber Morgan, director of collections and exhibitions, Rikke Foulke, conservator of paintings, and Aaron Levi Garvey, chief curator, discuss Andy Warhol’s Oxidation series and the origins of the Bank of America Art Conservation Project.

A Field Trip to the Forensics Laboratory

In the field of paintings conservation, mockups are an essential tool to better understand the materials an artist has used and the techniques they have applied. Since original artworks cannot be used for testing, mockups act as stand-ins. There are many benefits to this approach. Primary among them is that a mockup can be subjected to rigorous conditions created to replicate the altered appearance of the original while preventing further damage to the artwork being studied.

In records, materials, and audiotapes from The Andy Warhol Museum’s archives, staff identified the materials and processes Warhol used to make his Oxidation paintings between 1977 and 1978. Museum staff procured vintage metal powders identical to the originals in golden and copper-toned alloys and acrylic medium of the same manufacturer to replicate paint that Warhol would have used in the Factory in the late 1970s. In August the newly made paint was applied to modern commercially prepared 8” x 8” canvases. Volunteers copied the oxidation process by consuming Vitamin B, as was done in the Factory, and then a pipette was used to apply drops of urine to the prepared canvases. In these photographs, you can look through the results. A select few were delivered to the RJ Lee Group, an industrial forensics analytical laboratory, for testing.

While museum staff await the results of the analysis by the scientists at RJ Lee Group, you can browse the image gallery below to learn more about this field trip to the forensics lab.



Between the 19th and 21st of December 2023 a video camera recorded an image every 30 seconds of the preparation and reaction of a mock-up Oxidation painting.  Filming began when a canvas was prepared with metallic paint according to the protocol of Warhol’s Factory in the late 1970s.  Factory assistants mixed metallic powder with water then added the mixture to acrylic medium.  Application of two layers of this custom paint is seen in the first few moments of the film.  Preparation of the urine also followed Factory protocol by consuming Vitamin B.  Urine was applied with a dropper and seen in the next few moments of the time lapse video.  The rest of the footage captures the irregular and unpredictable reaction of the metallic paint to urine.

The standard pH of urine ranges from 6 – 7.5. and typical constituents of urine include water, urea, chloride, sodium, potassium, creatinine and sulfur.  Any of these materials may influence the outcome of oxidation.

Funding for the conservation of this artwork was generously provided through a grant from the Bank of America Art Conservation Project.