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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.

Image Gallery

A detail view of Andy Warhol's Oxidation (1978).

Andy Warhol, Oxidation (detail), 1978

A detail view of Andy Warhol's Oxidation (1978).

Andy Warhol, Oxidation (detail), 1978

A detail view of Andy Warhol's Oxidation (1978).

Andy Warhol, Oxidation (detail), 1978

A detail view of Andy Warhol's Oxidation (1978).

Andy Warhol, Oxidation (detail), 1978

A detail view of Andy Warhol's Oxidation (1978).

Andy Warhol, Oxidation (detail), 1978

Watch: Origins of the Project

Museum staff including Amber Morgan, director of collections and exhibitions, and Rikke Foulke, conservator of paintings, 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.

 

Image Gallery

Rikke Foulke, paintings conservator at The Andy Warhol Museum, walks toward an office building where the RJ Lee Group is located.

On a beautiful day at the end of August The Andy Warhol Museum staff visited RJ Lee Group to hand over samples and mockups for analysis. Bryan Conley, digital collections assistant; Alejandro Jimenez, videographer from the Pop District; and Rikke Foulke, associate conservator joined the scientists in their facility.

A scientist at RJ Lee Group opens the door to a Thermotron aging chamber.

Chris opens the door to the Thermotron, an aging chamber in which the temperature and humidity can be controlled to replicate conditions the Oxidation Painting experienced in June 2020. Mock-ups can be placed in here to observe if they present similar patterns of behavior such as dripping and color change.

Two purple-gloved hands hold tweezers to place a painting fragment in place.

Chris mounts a fragment from the tacking edge of the original Oxidation Painting.

A man sits at a desk using a digital microscope.

…and then examines it with a digital microscope.

Man conducts further analysis using the digital microscope.

Consulting Scientist Mike Deible, Ph.D. mounted a sample of the metal powder used to make the paintings on the digital microscope. Original cannisters of the metallic powders are preserved in the archives at The Andy Warhol Museum. Mike is showing us that the metal powder is comprised of flakes.

Bryan R. Bandli sits behind a digital microscope, working.

Bryan R. Bandli, Ph.D. is a Mineralogist, Microscopist and Principal Investigator for RJ Lee Group. He mounted a sample of brass powder in the scanning electron microscope. Bryan is using this instrument to identify the elemental makeup of our sample: copper and zinc, which are constituents of brass metal. Soon the scientists will share analysis and digitally captured images of materials.

Recreation

For three days in late December 2023, our staff used a camera to record an image every 30 seconds of the preparation and reaction of a mock-up “Oxidation” painting using a canvas 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 this video. Preparation of the urine also followed Factory protocol by consuming Vitamin B and it was applied to the mock-up canvas with a dropper. 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.