Materials Included In Kit

Additional Materials Required

Safety Precautions

The oil paints and solvent used in this activity are considered nontoxic. Wear chemical splash goggles, chemical-resistant gloves and a chemical-resistant apron. Wash hands thoroughly with soap and water before leaving the laboratory. Follow all laboratory safety guidelines. Please review current Safety Data Sheets for additional safety, handling and disposal information.

Disposal

Please consult your current Flinn Scientific Catalog/Reference Manual for general guidelines and specific procedures, and review all federal, state and local regulations that may apply, before proceeding. The excess diluted pigments should be transferred to a glass bottle with a vinyl backed screw cap for storage. The oily water remaining in the pans should be blotted thoroughly with paper towels before the remaining water can be poured down the drain. Do not wash the pans with soap! Allow the pan to air dry and save it for future marbling. The paper soaked with diluted oils should be bagged and closed to minimize odors in the room. It may then be disposed of according to Flinn Suggested Disposal Method #26a.

Lab Hints

• Enough material is provided in this kit for 30 students working in pairs or for 15 groups of students. This laboratory activity can reasonably be completed in one 50-minute class period. The prelaboratory questions may be completed before coming to lab, and the Marbling Paper Worksheet may be completed the day after the lab.
• To produce additional marbled papers, repeat the process. If different colors are desired, the surface of the water may be cleaned by using a piece of newspaper or paper towel to pick up the remaining colors. It is not necessary to empty the water out of the pan and start over.
• If a thin film of pigment is used, the marbled paper will be dry to the touch within an hour. However, because of the nature of the oil paints, they may not be completely dry for several days. After the marbled paper has dried, it can be folded and used for stationery or as a picture.
• When paper gets wet, it wrinkles. To smooth the marbled paper, allow it to dry a week or more. Sandwich the marbled paper between two clean sheets of paper. Iron the paper on a flat, heat-resistant surface—ensuring that the iron is not hot enough to scorch the paper.
• If desired, the diluted paints can be set up by the teacher ahead of time and stored in air-tight containers, however, letting the students prepare the “thinned” or diluted paints may increase the variation and creativity of their designs.

Teacher Tips

• This activity may be used to demonstrate viscosity, intermolecular forces, polar and nonpolar molecules, surface tension, etc.
• Have students research various paper-marbling techniques from different countries and time periods.
• An extension of this activity is marbling fabric. Natural fibers such as cotton or silk generally give better results than synthetics.
• Many marbled images and patterns may be found online. For example, visit http://marbleart.us/Examples.htm (Accessed October 2009).
• A video of this lab activity, Marbling Paper with Oil Paints, presented by Steve Long, is available for viewing as part of the Flinn Scientific “Teaching Chemistry” eLearning Video Series. Please visit the eLearning Web site at http://elearning.flinnsci.com for viewing information. The video is part of the Classroom Fun video package.

Answers to Prelab Questions

1. Why do the oil paints flow over the surface of the water and not roll up into spheres?

   Oil is nonpolar and nonpolar molecules do not have strong intermolecular forces to attract each other or other molecules. They easily slide over the surface of the water because of the high surface tension of the water.

2. What is the purpose of Turpenoid Natural in this laboratory activity?

   Turpenoid Natural thins out the oil paints resulting in different viscosities and patterns of the paint.

3. Why do people marble paper?

   Historically people marbled covers or the inside of books to enrich the look. People continue to marble paper today to create customized designs.

Sample Data

Observations

Describe the observations after adding the diluted paint to the pan of water.

The diluted paints spread over the water while staying on the surface. The more dilute the paint, the thinner and further it spreads. Colors mix and create many patterns.

Answers to Questions

1. Explain why the paint added to the pan of water spread out and floated on top of the water without mixing into the water.

   The paint and Turpenoid mixture (nonpolar) is not miscible with water (polar). The water molecules are more attracted to each other than to the nonpolar molecules of the paint. The surface tension on water is very high which helps support the weight of the “floating” paint.

2. Predict what would happen if water-based paints were used instead of oil-based paints in this activity.

   If water colors were used they would mix directly into the water and the colors would also mix since they would have mainly the same polarity. This would give a mottled appearance without an easy way of extracting the colors onto paper or other media.

3. What might happen if a drop of dish soap were added to the paint/water mixture? (Dish soap contains long-chain molecules with both a polar end and a nonpolar end.)

   If dish soap, which has both polar and nonpolar ends, were added, it would break down the surface tension of the water and the two distinct layers—oil paint and water—would no longer exist.

4. Attach the dried marbled paper product to this worksheet. 

   Student results will vary. If desired, students can be asked to create certain marbling patterns.

References

Special thanks to Eric Meier for sharing his images. See http://www.freewebs.com/chromatictransport/aboutme.html (accessed October 2009).

Introduction

Many people have heard the old adage that oil and water don’t mix—well, thank goodness they don’t! In this lab, which combines chemistry and art, you will use the properties of oil paints and water to create colorful, customized paper patterns.

Concepts

• Intermolecular forces
• Solubility and miscibility
• Surface tension
• Viscosity

Background

Paper marbling is a method of transferring color from the surface of a liquid to paper that dates back to the 12th century. The Japanese technique is called sumi nagashi or “ink-floating.” There are many marbling techniques that involve different types of materials for both pigments and the liquids. In this particular activity, oil-based paints thinned with an organic solvent will be floated upon untreated water. Artists’ oil paints generally contain inorganic pigments mixed into an organic linseed oil binder. Linseed oil, which is a triglyceride containing unsaturated fatty acids, “dries” by creating crosslinks between molecules. The crosslinks are formed when double bonds in the fatty acids open up and connect with adjacent molecules. This forms a film or skin that seals in the inorganic pigments. Light is needed for this slow cross-linking or polymerization reaction to occur. The thinner the layer of linseed oil, the faster the oil paint dries because the crosslinks form more quickly.

By varying the relative amounts of the oil pigments and water, the effects of surface tension, solubility, and density also change, resulting in unique color patterns on the paper. Molecular compounds consist of molecules—groups of atoms held together by covalent bonds. The physical properties of a molecular compound, including its solubility, depend on the polarity of the molecules. Molecules are classified as polar or nonpolar based on the nature of the electron sharing among the atoms in a molecule. Polar molecules tend to exert stronger attractive forces than nonpolar molecules. The polarity of a compound determines the types of intermolecular attractive forces between molecules and is an important factor influencing solubility of solutes and solvents. The rule of “likes dissolve likes” means that nonpolar solutes tend to dissolve in nonpolar solvents and polar solutes tend to dissolve in polar solvents. Oil paints are nonpolar molecules. Water, the universal solvent, is very polar with strong intermolecular attractive forces including hydrogen bonding. The strong attractive forces of water leads to other properties such as surface tension.

The action of surface tension will be seen as different color oil paints are placed on the water. Molecules on the surface of a liquid are attracted inward by those molecules immediately below the surface layer. The surface contracts under these attractions and acts as though it has a “skin.” The amount of energy required to break through this “skin” on the surface is considered its measure of surface tension. Water has a fairly high surface tension. The surface tension of water is the reason that water (polar) will bead on a nonpolar substance such as a leaf. The two opposing surfaces will respond by reducing the surface contact with each other—the water will form a sphere. The sphere has the smallest surface area of any shape with the same volume. It is this surface tension property that allows certain insects to walk on water and objects that are denser than water to float on the surface of the water. Nonpolar oil paints will flow over the surface of the water like a drop of gasoline will spread out on a puddle.

In this lab, adding different amount of paint thinner to the oil paints will produce mixtures with different viscosities. Viscosity refers to the resistance to flow of a substance. Two main factors that influence viscosity are molecular shape and intermolecular forces. For example, maple syrup has a higher viscosity than water and an organic solvent like hexane has a lower viscosity than water. The more paint thinner that is used to dilute the oil paints the lower the viscosity of the diluted paints will be. The viscosity will govern how the diluted paints will spread over the surface of water. The different physical properties of oil paints and water produce the ability to marble paper.

After the diluted oil paints have been applied to the surface of the water, they may be manipulated to produce a variety of patterns. Some historical examples include stoning, combing, and swirling. Stoning is a technique where large amounts of paint are held together, giving rise to a pattern that looks like stepping stones. Swirling is where the colors are mixed with a fine pointed object—historically a feather. Combing uses special combs or rakes to produce design patterns with the colored paints. Different combs give different effects and with a comb the pattern is repeated by as many teeth as the comb has. Below are some examples of stoning, combs and combing patterns, and swirling as well as combinations of the three.

Double rake (Bouquet Peacock)

Experiment Overview

Diluted oil paints will be floated onto the surface of water to produce a variety of patterns. The paint images will then be transferred onto paper to create unique marbled paper designs.

Materials

Prelab Questions

1. Why do the oil paints flow over the surface of the water and not roll up into spheres?
2. What is the purpose of Turpenoid Natural in this laboratory activity?
3. Why do people marble paper?

Safety Precautions

The oil paints and solvent used in this activity are considered nontoxic. Wear chemical splash goggles, chemical-resistant gloves and a chemical-resistant apron. Wash hands thoroughly with soap and water before leaving the laboratory. Follow all laboratory safety guidelines.

Procedure

1. Fill the 8" x 8" aluminum pan with at least one inch of water.
2. Prepare the diluted oil paints by squeezing a small 5 mm portion of paint from a tube into a small paper cup.
3. Add approximately 3 mL (one pipet-full) of Turpenoid Natural to the paint and mix carefully and thoroughly using a wooden splint. Test the mixture by placing a few drops in the pan of water. If it spreads too much, add more pigment; if it does not spread or sinks, add more solvent. (This is NOT an exact science—the variations are part of the charm.)
4. Cut the paper to fit the size of the pans used. Legal size paper cut in half works well (see Figure 1).
   {12839_Procedure_Figure_1}
5. Place layers of newspaper around the work area.
6. Use the pipet to gently float different oil paints onto the surface of the water. The water should be covered with a very thin film of paints. If the pipet is used to “shoot” the paints onto the water layer, the paint mixture will sink. Note: The most common error is to place too much pigment on the surface, creating a thick pigment layer.
7. Use a pipet tip to make swirl patterns in the paint, if desired.
8. Fold up about an inch of the paper to make a convenient handle for dipping or skimming the paper across the water. The paper that is skimmed across the paint mixture should be about 7" x 7¼" (see Figure 2).
   {12839_Procedure_Figure_2}
9. Hold the paper by the handle and touch the paper to the marbled surface in a rolling motion to minimize the formation of air bubbles. The bubbles will produce white spots on the paper. A quick, smooth motion will produce nice results with minimal problems.
10. Use the handle to quickly lift the paper off the surface of the water. Note: Do not let the paper go under the water or remain in contact with the water too long.
11. A second paper may sometimes be floated in the same pan without adding more pigment, resulting in another marbled paper with lighter colors and a more delicate pattern.
12. Place the marbled paper face-up on paper towels to dry.
13. Consult your instructor for appropriate disposal procedures.

Student Worksheet PDF

12839_Student1.pdf