Beginning Level Activity
In this activity students will make paint using raw umber as pigment.
1. To motivate students and give them some context about illuminated manuscripts, read Marguerite Makes a Book to the class.
2. Display an image of the Bosschaert painting or hand out copies. Tell students that the paints used to create the original artwork were made by the artist in his studio, since paint was not available for sale in the 17th century. Each color is made using a different paint or mixture of paints. Ask students to identify all the colors they see in the painting and create a chart of all colors mentioned.
3. Ask students to describe the characteristics of liquids and solids and discuss the differences between the two. Using student input and background information, write a definition for "liquid" and "solid" and list some examples of each on the board.
4. Explain what a solution is and ask for examples. Explain that paint is a solution because it is a mixture of a liquid and a solid.
5. Give each pair of students a copy of the student handout Watching Paint Dry, a piece of clayboard, a pencil, a mortar and pestle containing one tablespoon of raw umber, and a paintbrush. Ask students to examine the raw umber by looking at it, smelling it, and rubbing it between their fingers. Ask them where they think it comes from and discuss responses. Tell students that umber is a type of earth, and that many paints have different colored earths as their base. Explain that earth was the oldest material used to create paint and that it dates to prehistoric times. Ask students whether the umber is a liquid or a solid. Finally, tell students that the solid material used in paint is called the pigment. The pigment gives paint its color. Many pigments are made from things that can be found in nature, like earth, minerals, rocks, plants, and even parts of animals and insects.
6. Ask students what liquid they think needs to be added to the umber to make paint. Explain that they will be adding two different liquids, or binders—egg glair and oil—to their pigment and documenting the differences in the resulting paints.
7. Have students draw a line across the center of their clayboard and label one side egg and the other oil. Add one half teaspoon of oil to the umber in each pair's mortar and pestle. Have student partners take turns mixing the pigment and oil together. It will seem dry at first but will slowly take on the consistency of chocolate frosting or mayonnaise. (This will take about 10 minutes.) Once the oil paint is ready, have student pairs paint the entire oil side of the clayboard with the oil-based paint. Have students record the time and date on the Watching Paint Dry student handout.
8. Give each student pair a cup containing one teaspoon of umber and a clean paintbrush. Add a teaspoon of glair, made from egg whites, to the umber in each pair's cup. Have students mix it until the umber has been incorporated into a smooth mixture. (This will take just a minute or two.) Students will paint the egg glair side of the clayboard with this egg-based paint. After painting the board, students should note the time and date on the Watching Paint Dry student handout. Put the paint samples aside to dry and clean up. Mortar and pestles should clean up with soap and water. Turpentine might be needed to wash oil-based paint out of the paintbrushes (this should be done by teacher).
9. Have students monitor the paint samples on their clayboard and chart the drying time of each sample. The egg-based paint will dry very quickly; the oil-based paint will take a few days to dry.
10. Students should fill in the Watching Paint Dry student handout with their findings.
11. Discuss why the oil and egg white dry at different speeds to address the concept of evaporation. Egg-based paint dries due to evaporation, which occurs when a liquid moves into the air. Oil-based paint, on the other hand, dries by a different, slower process. (Oil-based paint dries through a process called oxidation. For more on the properties of oil paint, visit the Smithsonians Museum Conservation Institute Web site's page about "The Drying of Oils and Oil Paint".)
Intermediate Level Activity
In this activity students will make paint using charcoal black as pigment.
12. Tell students that they will be making charcoal, which they will then use as a pigment to create black paint. Explain that they will cook wood in a crucible. Have students predict what will happen if one of the crucibles is left ajar, rather than closed, while heating the wood. Students will test their hypotheses.
13. Place one or two pieces of pine in two different crucibles. Mount the crucibles over burners. Cover one crucible with a lid and leave the other ajar.
14. After two minutes, light gases will escape from around the lids of the crucibles. Once all gases have burned off, the charcoal is ready. Turn off the burners and let the crucibles sit until cool. Do not remove lids until cool.
15. Uncover crucibles and have students describe what they see in the two crucibles, comparing the two products. The crucible with the closed lid will have charcoal inside, while the crucible that had the lid ajar will have produced ash. Have students predict the reason for the different results.
16. Remove the charcoal and grind it in a mortar and pestle until it is a fine powder. Sift the powder to remove large chunks and then add oil in a 1:4 ratio of charcoal to oil. Grind, or mull, the mixture until the paint has reached the consistency of thickened cream or a heavy soup.
17. Have students research the chemical changes that happen when charcoal is created.
18. Have a discussion in class, based on the findings from the research, about why the lack of oxygen in the crucible led to transformation of wood into charcoal, and what gases were burned off during transformation.
Advanced Level Activity
In this activity students will make paint using cobalt blue as pigment.
19. Have student pairs measure out and combine the following in a mortar: 1 g cobalt (II)-chloride (CoCl2 · 6H2O) and 5 g aluminum chloride (AlCl3). Students should grind these together and place the mixture in a test tube.
20. Heat the mixture in the test tube over a gas burner for about 3 to 4 minutes. The mixture will turn blue when the reaction is completed. Empty the contents into a mortar and let it cool.
21. Add a few drops of linseed oil to the mortar and grind the mixture with the pestle until the paint is the consistency of thick cream or a heavy soup. Add additional drops of linseed oil as needed to produce this consistency.
22. Students should document the process of creating the cobalt blue paint, research the chemical reaction that occurred to create the cobalt pigment, and answer the following questions:
• What does grinding do to the compounds in the mortar? (physical change – breaks bonds)
• What does heating do to the compounds? (chemical change – re-bonds)
23. Have students use the three pigments they made to paint illustrations of the molecules used to make cobalt blue (CoCl2 · 6H2O and AlCl3).
Art-Making Activity
1. Have students use the paint they created to paint a still-life. Before they begin painting, they will warm up by sketching objects depicted in Flower Still Life by Ambrosius Bosschaert.
2. Pass out copies of Flower Still Life or project an image of the painting in your classroom. Students will use pencils to sketch three objects in the painting of their choice. Students should pay attention to Bosschaert's use of shading and overlapping shapes to create objects that look three-dimensional.
3. After students have sketched three objects, provide them with clayboard, paint, brushes, and paper towels.
4. Beginning students will create a monochromatic composition with the egg-based raw umber paint (egg-based paints are known as "tempera"). In order to create gradations in shade, they will need to use varying layers of paint. You may also wish to have them focus on painting one object like a flower on a table.
5. Intermediate students will create two monochromatic compositions—one with the raw umber and one with the charcoal black, as the egg-based paint will not combine well with the oil-based paint. They will also need to use the layering technique, as they are using one color. They should also consider leaving areas of the clayboard blank so that the color of the clayboard itself can act as an additional color. Students can create compositions that include two or three objects on a table.
6. Advanced students will create one monochromatic composition with the raw umber and one monochromatic composition with the charcoal black and the cobalt blue, as they are both oil-based paints. The oil-based pigments can be combined to create a variety of shades of blue. Advanced compositions should include about four or five objects grouped together in a complex composition.
7. Students should sketch their composition on the clayboard with pencil before they apply the paint. Students should apply thin layers of paint to the surface, starting with the lightest shade.
After paintings are complete, students should share their paintings with one another and discuss the challenges and rewards they found in using homemade paint.
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| Flower Still Life, Bosschaert the Elder, 1614 |
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