Science, Art and Technology

So You Want to Buy a Painting

Teacher: Patricia A. Riley
School: Lincoln Park High School
Suggested Grade Level: 12
Title: So You Want to Buy a Painting?
Subject: Chemistry
Time: 6 days

Index
Background
Objectives
Materials
Procedure

Day 1: Introduction to Unit
Day 2: Student Self-Guided Tour
Day 3: Lesson Plan—Creating Paintings
Day 4: Lesson Plan—Authenticating Paintings
Day 5: Preparation of Team Backboard
Day 6: Student Presentations

Vocabulary List
Assessment
Teacher Resources
State Goals and Chicago Academic Standards

Background

Students pretend that they want to buy a painting by Vincent van Gogh, Claude Monet, or Jackson Pollock, but know that no one makes such a major purchase without first researching the artist and his works and methods of authentication.

Students study selected paintings by van Gogh, Monet and Pollock during a self-guided tour of the Art Institute. They conduct library research into the lives of these three artists and their artistic styles. Students also research the chemical and physical methods for determining the authenticity of a painting. Upon returning from the self-guided tour, the class divides into groups of four. Each student makes three paintings, one each in the style of the three artists. They should try to use subject matter and style typical of each artist. At least one of these paintings will be considered “authentic” and at least one a “copy.” After completing their works, students swap their paintings with the other members of their group, and each student must determine if the painting they have been given is “authentic” or a “copy” through a series of chemical tests. Each group of students then presents its findings before the class in the form of a poster.

To complete this project, students should have had some prior experience with modern methods of instrumental analysis, including mass spectroscopy, ultraviolet-visible spectroscopy, infrared spectroscopy, X-ray diffraction, and gas chromatography. Many of the chemical methods used to determine the authenticity of a painting involve these techniques.

Objectives

Research physical and chemical methods used in authenticating paintings (e.g., ultraviolet fluorescence and spectroscopy, infrared spectroscopy and reflectography, X-ray diffraction, microscopy, pigment analysis, and gas chromatography)
Compare and critique intrusive and non intrusive methods for authenticating paintings.
Determine the authenticity of a painting through chemical, ultraviolet, and microscopic paint-chip analysis
Select procedures and materials, collect and organize data, and draw conclusions in order to authenticate a painting

Student will also

Understand pertinent vocabulary (style, pigment, Impressionism, Post-Impressionism, Abstract Expressionism, Pointillism, palette, primary color, secondary color, and perspective) and the lives and works of artists Vincent van Gogh, Claude Monet, and Jackson Pollock.
Compare and contrast the painting styles of van Gogh, Monet, and Pollock
Prepare three separate small paintings, one each in the style of van Gogh, Monet, and Pollock. At least one of these paintings must be “authentic” and one a “copy.”
Determine the “authenticity” of a painting through knowledge of the artists’ styles, palettes, and techniques.

Materials

Red, green, yellow, blue, black, and white acrylic paints
Red, green, yellow, blue, black, and white fluorescent paints
Brushes
Tweezers
X-ACTO knife
Small test tubes
Microscope
2” x 3” pieces of foam board, canvas board, cardboard, or heavy paper
Pb(NO₃)₂, crystalline lead chromate
K₂CrO₄ potassium chromate solution
Ultraviolet light source
Microscope slides

Procedure

Day 1: Introduction

Explain that each student has just inherited a great deal of money and wishes to buy a painting by Vincent van Gogh, Claude Monet, or Jackson Pollock but does not know whether the particular paintings available are authentic. What would the students need to know in order to make a wise purchase?
Have students research the lives and works of the artists, research methods to authenticate such works, consult experts, and examine known works by the artists.
Show slides of various paintings. Invite discussion of the images by asking open-ended questions, such as: How does the painting make you feel—energized, agitated, warm, happy, or something else? What kinds of brushwork, lines, and colors do the artists use? How do the artists move your eye around the paintings? What is the focus of each painting? How do you know?
Divide the students into groups of four and hand out copies of the Student Self-Guided Tour. Explain that each team is expected to visit the Art Institute, either after school or over the weekend, by a certain date. Give teams time to decide on a date for their visit.
Homework: To prepare for making a major purchase, students conduct library research.
1. Define the art terms on the vocabulary list. (Use an art dictionary or encyclopedia. These terms may have different meanings in everyday life.)
2. Find out as much as possible about the life, times, and work of the three artists. There are books available in the public library and a vast amount of information online.

Day 2: Student Self-Guided Tour

Students must bring their Chicago Public School ID card, which will grant them free admission to the Art Institute (students from outside Chicago will need to pay to enter), and their copies of the Student Self-Guided Tour. They must also bring pencils to write with and a hard surface, such as a clipboard, on which to write.
Students should allow at least two hours for their tour.
The completed self-guided tour homework is due the first day of school after the tour.
Homework: Study the procedures for creating and authenticating a painting. (below)

Day 3: Creating the Painting

Teams should agree upon what constitutes an “authentic” Monet, Pollock, or van Gogh. For example, one team may decide that a real Monet may be painted on canvas with fluorescent paint but may contain no lead chromate and may have no paint layers or red paint. A real van Gogh may have a different set of characteristics, as will a real Pollock. The teammates must record this information in their lab journals.
Each student makes three paintings, one each in the style of the three artists. At least one must be “real” and at least one must be a “copy.” Students are told not to worry about replicating specific paintings; concentrate on creating paintings that show typical subject matter, characteristic brushstrokes, and artistic styles of the artists.
3. For each painting, each student selects 2” x 3” piece of backing, makes a pencil sketch of the painting, and then uses the acrylic paints to give the work detail, texture, and color. They should try to convey the same feeling the artist’s work gave them. Tell them that they may layer paints or premix them before applying them to the backing. They may also apply paint heavily to create thick, textured layers.
Students use tweezers to embed small crystals of Pb(NO3)2 in the thicker areas of paint. This should be done immediately after applying the paint, since acrylic paint dries quickly. Be sure students cover the crystals with another layer of paint.
When the acrylic paint is dry students apply small dots or lines of fluorescent paint to the surface, using the same color as the acrylic paint.
Students label the backside of the painting with their name. Paintings are set aside to dry.
Students repeat steps 3–6 for their other two paintings.
Students record details of what they did for each painting in their lab journals.

Day 4: Authenticating the Paintings

Tell students to exchange paintings within their teams. No one should have his or her own painting.
To test for fluorescence, students place each painting inside the ultraviolet light viewer and turn on the UV light source. Have students record their findings in their lab journals for each painting.
To test for the presence of lead (Pb(NO^₃)₂), students use an X-ACTO knife to remove a small chip of paint from a thicker area. Students place the paint chip into a test tube with 5 mL of 0.1 M K₂CrO₄, shake the test tube vigorously several times, and look for the appearance of a yellow precipitate. Students record all observations.
To test for layering of paint, students use the X-ACTO knife to remove another chip from a thick area. Students carefully make very thin slices through the chip, place the slices on a microscope slide, and examine them under a microscope to determine whether the artist used premixed paints or layered paints.
After completing all tests on the three paintings and comparing their findings to thier lists that define what a “real” painting is for each artist, what conclusions can students draw? Ask students to explain their reasoning fully in thier lab journals.
Ask students: What chemistry-related problems did they encounter? If these were valuable paintings, which tests would have to be used with caution and why? Are there other tests they read about that could be used instead?
Ask students: What art-related problems did they encounter? What were these problems? If these were encountered with an actual painting, what courses of action would they take?
Homework: Each student writes up his or her findings and conclusions for each painting in a lab journal.
Homework: Each team is to bring a backboard for the team report.

Day 5: Preparation of the team backboard

Teams prepare backboards illustrating what they learned.
Students include the criteria for what constitutes a “real” Monet, van Gogh, or Pollock.
Students include the paintings they studied and their findings. Photos may help.
Materials provided to each team:

Colored construction paper
Scissors
Assorted colored markers
Glue sticks

Students state the chemical equations for the reactions that occurred.

Day 6: Presentation of the backboard

Each team presents its findings. All teammates should actively participate in discussion/presentation.
Students explain which chemical tests were intrusive, why these tests might be a problem, and which tests were ambiguous.
Students discuss other analytical tests that might be used, provided the necessary equipment were available?
Students explain which artistic clues were most helpful and how the styles of these three artists are similar or different.

Vocabulary List

Impressionism
Post-Impressionism
Modernism
Pointillism
spectrum
canvas
palette
pigment
style
composition
primary colors
artist’s board
oil paint
chromatic contrasts
complementary colors
improvisation
secondary colors
perspective

Assessment
Assess students individually on their lab journals and on the
completion of their Student Self-Guided Tour. Students will also receive a team grade
based on their backboard presentations.

Teacher Resources
Greenberg, Barbara R. and Dianne Patterson. Art in Chemistry: Chemistry in Art. Teacher Ideas Press, 1998.

State Goals and Chicago Academic Standards

Chemistry
State Goal 11/Chicago Academic Standard B
Chicago Framework Statements 5, 8, 9
State Goal 12/Chicago Academic Standards C
Chicago Framework Statement 1
State Goal 13/Chicago Academic Standard D
Chicago Framework Statements 1, 3

Conceptual Statements–Chicago Program of Study
Properties of Matter: Matter occupies space and has mass. Understanding atomic structure is the basic foundation for investigating matter. The identification of matter is made possible through physical description.

Supporting Ideas
Matter is classified according to its elements (atoms and molecules), compounds, mixtures, physical states (which is determined by the kinetic energy of its atoms), and physical properties (which depend on the arrangement of the atoms and their atomic structure).

Trends in physical properties and their correlation to the atomic structure of elements are found in the periodic table.

Atomic structure is determined by the number of protons, neutrons, and electrons and their spatial distribution. Atoms of the same element with different numbers of neutrons result in isotopes.

Fine Arts
State Goal 25/Chicago Academic Standard A
Chicago Framework Statement 1
State Goal 26/Chicago Academic Standard A
Chicago Framework Statement 1