Oxidations and Abstraction

Explore Chemical Reactions of Acids and Metallic Paint
Andy Warhol, Oxidation Painting, 1978, ©AWF

Using Warhol’s Oxidation paintings to explore abstraction, students produce their own oxidation paintings experimenting with the effects of acids and bases on copper-based paints.

Grade Levels:



Art, Science, Chemistry 

Suggested Time Frame:

2 class periods 


  • Students discuss, compare and contrast Warhol’s Pop Art work with his abstract paintings from the 1970s and 1980s
  • Students discuss how oxidation occurs, then hypothesize how Warhol created oxidation in his paintings
  • Using photos of abstractions found in nature, students guess what the images depict and how the abstractions might have formed
  • Students use various liquids on copper-based paint to create abstract paintings
  • Students analyze the variables in the process of creating an abstract work of art using chemical experimentation
Andy Warhol, Oxidation Painting, 1978, ©AWF
Andy Warhol, Oxidation Painting, 1978, ©AWF

About the Art:

In the late 1970s and early 1980s, Andy Warhol focused for the first time on the exploration of abstraction. While paintings he made in the 1960s with repeated blocks of imagery forming a patterned surface—and even some early experiments in the 1950s suggest a certain abstraction—his abstract works in the late ’70s and ’80s have no discernable representational imagery. With these paintings, often created in large series that included mural-sized works, the artist dives into the beauty and mood of color and texture in a way he had not done before. Yet, Warhol’s delving into abstraction is not without coy references and plays between what’s real and what’s abstract. For example, the Shadows series are abstract paintings of what is ostensibly a “real” shadow.

In December 1977 Warhol began the Oxidations, iridescent canvases made up of coppery yellows, oranges and greens. Surprisingly, the only paint used by the artist in this very “painterly” work was the metallic copper background. Warhol invited friends and acquaintances to urinate onto a canvas covered in metallic paint in order to cause oxidation. The uric acid reacted with the copper in the paint, removing components of the pure metal to form mineral salts. Some colors developed immediately while others like blue and green formed later on top of the red or brown copper oxides.  Warhol and his collaborators experimented with both pattern and coloration by using a variety of metallic background paints and by varying the maker’s fluid and food intake. Critics have made numerous comparisons between the Oxidation series and Jackson Pollack’s famous drip paintings from the 1940s and early 1950s.

Andy Warhol Quote: 


“It was just copper paint and you would wonder sometimes why it did turn green and sometimes it didn’t.  It would just turn black or something.  I don’t know what made it do that.” 

Francis, Mark. Andy Warhol: 1956-86: Mirror of His Time. The Andy Warhol Museum, Pittsburgh, and the Asahi Shimbun with the Museum of Contemporary Art, Tokyo, 1996. 
Andy Warhol, Oxidation Painting, 1978, ©AWF
Andy Warhol, Oxidation Painting, 1978, ©AWF

Discussion Questions:

  1. Compare and contrast Andy Warhol’s Soup Cans to his Shadows and Oxidations paintings. While some of the differences are obvious, how are they similar?
  2. What is the difference between realism and abstraction?
  3. Warhol created beautiful colors and forms through what some consider an offensive process. Do you think artists should be allowed to make art out of any material or process?
Petri dishes with various acids and bases that will react with the copper paint once applied
Petri dishes with various acids and bases that will react with the copper paint once applied


Canvas squares or heavy white paperPetri dishesPaintbrushes
*Modern Masters Copper Paint (water-based metallic paints contain real metal particles that will tarnish naturally over time and when exposed to the elements)Paint traysStudent Handout 1: Nature Cards 
Modern Masters Patinas (aging solutions to be used over the metallic paints. These solutions speed the aging process to create beautiful, authentic black, blue, or green patinas)Eye droppersStudent Handout 2: Acids and Bases 

* Reactive metal paints can be applied using a brush roller or paintbrush. Additional information on these products can be found at these online suppliers:



Abstraction found in nature
Abstraction found in nature


  1. Discuss where abstraction is found in nature.
  2. Print out Handout 1, cut individual cards and distribute these to the class. Ask students to guess what the photos are and to describe how the material that they see formed.
  3. Discuss acids and bases using Handout 2.
  4. Explain the basic chemical process of oxidation.
  5. Prepare the painting surface using 6" x 6" or 10" x 10" stretched canvas or heavy paper; apply two coats of copper paint.
  6. Set up various petri dishes with both acids and bases (vinegar, water, patinas) along with droppers. Paint trays and brushes can also be used.
  7. Students should experiment with the acids and bases by dropping liquid onto their copper paintings.
  8. Ask students to take notes while working and to hypothesize how they think their paintings will turn out. Which liquid do they think will work better than others? Why?
  9. Allow the liquid to dry; have students note how their paintings change over time.


Form one large abstract painting using the individual oxidations. Through discussion or writing students should:

  • Review their notes and explain how they used various materials.
  • Identify the effects of different acids and bases on the coloration of the metallic ground.
  • Evaluate whether or not the grouping of paintings is a successful abstraction. Do they evoke a sense of wonder, feeling or emotion? Are they beautiful or appealing?
  • Explain what they would do differently if they used this process again.

Chemistry Extension: 

Explore the chemistry behind corrosion. Write the chemical equations for the materials used in each painting.

Warhol Education Rubrics

Click the Warhol Rubric headers below to reveal associated rubrics to which this lesson applies.

Critical Thinking
Creative Process