Colorful Chemistry Creations: Make Your Own Sun Print with Color and Sunlight!
Abstract
You've probably heard of hand prints and fingerprints, but what about a Sunprint®? To make a Sunprint, place an interesting object on a special sheet of Sunprint paper, expose it to the sun for a few minutes, immerse the paper in water, and watch as a permanent image appears! Sunprint paper can be used to make beautiful and eerie prints, using just sunlight and water. Sunlight is actually a mixture of different colors of light. In this chemistry science fair project, you will test which colors of light work best to form Sunprint images.Summary
David B. Whyte, PhD, Science Buddies

Objective
Determine how different colors of light affect the brightness of a sun-print image.
Introduction
Take water, sunshine, and some creativity, and what have you got? Hours of enjoyment, making photographic-type pictures, called Sunprints, shown below in Figure 1. A Sunprint is made on special Sunprint paper, which can be used to make images of all sorts of objects. To make a Sunprint, place an interesting object on a sheet of Sunprint paper, expose it to the sun for a few minutes, dip the paper in water, and watch as a permanent image appears.

Figure 1. Sunprints of a flower and of some household items.
When you expose Sunprint paper to sunlight, and then rinse the paper with water, the areas of the paper that were exposed to sunlight appear dark blue. If there is an object blocking the sunlight, the paper under the object appears white. Sunprint paper has a light-sensitive chemical soaked into the paper. This chemical (called Berlin green) is a light-green color and it washes away when the paper is soaked in water. The chemical washes away because it dissolves in water (which means the chemical is water-soluble). When light hits the chemical Berlin green, it causes a light-activated chemical reaction. The product of the chemical reaction turns into a dark blue chemical, called Prussian blue, after rinsing. This chemical does not wash away in water (meaning it is insoluble in water). Because the Berlin green washes off and the chemicals formed by the chemical reaction with light stay on the paper when rinsed, the areas that were shaded by the objects form white images on a blue background.
Terms and Concepts
- Sun print
- Light-sensitive chemical
- Berlin green
- Water-soluble
- Chemical reaction
- Product of a chemical reaction
- Prussian blue
- Insoluble
- Light filter
- Particle
- Trial
Questions
- Based on your research, what are the primary colors?
- Why do you rinse the sun-print paper after exposing it to sunlight?
- What are some water-soluble chemicals that you can find in your kitchen? What about insoluble?
Bibliography
- Lamb, A. and Johnson, L. (2002, July). Color. Retrieved November 24, 2009.
Materials and Equipment
- Clear plastic sheet protector; available at any office supply store
- Ruler, metric
- Scissors
- Sunprint or SunArt® paper; available online from Amazon.com
- Permanent markers, chisel tip; red, orange, yellow, green, blue, and purple
- Timer
- Cardboard, 30- x 30-cm piece
- Water
- Lab notebook
Disclaimer: Science Buddies participates in affiliate programs with Home Science Tools, Amazon.com, Carolina Biological, and Jameco Electronics. Proceeds from the affiliate programs help support Science Buddies, a 501(c)(3) public charity, and keep our resources free for everyone. Our top priority is student learning. If you have any comments (positive or negative) related to purchases you've made for science projects from recommendations on our site, please let us know. Write to us at scibuddy@sciencebuddies.org.
Experimental Procedure
- Assemble the Sunprint kit and other materials.
- Cut a 10-cm x 15-cm rectangle from the sheet protector plastic.
- Label the piece "#1" with small print in the upper left corner with the black permanent marker. This represents that this is your first trial.
-
Write the following three-letter words on the plastic sheet, using the color of ink that is listed. You can use any pattern you like for the placement of the words, but keep the size of the letters the same.
- RED in red ink
- ORA in orange ink
- YEL in yellow ink
- GRE in green ink
- BLU in blue ink
- PUR in purple ink
- Cut a 10-cm by 15-cm piece of Sunprint paper.
- Following the directions that came with your Sunprint kit, make a Sunprint using the plastic sheet.
- Expose it to sunlight for 2 minutes. Use the timer to help you keep track of the time.
- Cover the Sunprint with the cardboard to stop the reaction at 2 minutes.
- Bring it inside and rinse and dry the paper.
- Look at your results.
-
Make a data table for this trial in your lab notebook with each of the colors that you used.
- List the colors in order, with the color that has the brightest letters first.
-
Repeat steps 2–11 two more times. This ensures that your results are accurate and can be repeated.
- Label the new plastic sheets in step 3 "#2" and "#3" for each new trial (a total of three trials).
- Based on your results, which colors form strong, weak, or no images? Can you see a pattern in the results? Remember, colors that form images are colors that cause the chemical reaction that forms Prussian blue.

Ask an Expert
Variations
- Try using colored lights. Which colors of light are best at forming Sunprint images?
- Is ultraviolet light required for the Sunprint reaction? Use clear items that block ultraviolet light, such as glass, to test this. You can also see if sunscreen on plastic sheets forms an image.
- Look up the wavelengths of the different-colored light. Add this data to the table.
- Add a column to your data table that has the complementary color for each color of ink you used. Analyze your results in terms of which colors are blocked by the colored ink.
Careers
If you like this project, you might enjoy exploring these related careers: