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Echoes and Impressions

Adapted from a Portland Public Schools Arts project
Inspired by the exhibition Volcano! Mount St. Helens in Art

Download the PDF or follow the instructions below.

A compression fossil is formed when plants or animals are placed under physical pressure by layer upon layer of sediment that eventually hardens into rock. It’s very common to find fossils formed this way along rivers and lakes where fine sediment quickly encases an object before it has time to decompose—like during the Mount St. Helens eruption. In a process known as carbonization or distillation, a plant can be reduced to a carbon film that displays the exquisite details of the fossil.

Fossils are like a snapshot in time. They provide evidence of events in nature and of the lives of plants and animals. In this project, we invite you to create your own fossil-like artwork from natural materials outside your home. Or, as an alternative, consider using an object inside your home. What kind of fossil might be left by a meaningful event in your life?


  • air-dry clay or paper clay
  • metallic paints or markers
  • natural materials (leaves, twigs, etc.)
  • paintbrushes (if using paint)


Step 1:
Take a nature walk around your neighborhood. Gather leaves, flowers, twigs, stones, or other natural materials to use for making clay impressions. As you walk, notice the weather and the time of year. How does the season affect your materials? What other features of nature do you observe?

Step 2:
Return home with your materials and place them on a flat surface along with your clay. Form the clay into balls about three to four inches in diameter. Then, flatten the balls into disks, smoothing the edges. Press one of your natural materials into the clay disk.

Step 3:
Apply marker or metallic paint over the surface, including both the natural object and the top of the clay disk. The marker or paint does not need to be evenly spread.

If you’re using paint, use the dry brushing technique: Dip only the tip of your brush into the paint, then dab it with a paper towel, so the brush is not very wet. Then, use short, quick brushstrokes in different directions.

Step 4:
Remove the natural materials from the clay. Leave the clay to dry.

Optional Steps
Step 5:
Once clay & paint are fully dry, apply a contrasting color of paint as a wash, 50% paint and 50% water. Wipe the surface so the paint stays in the impression or details of the “fossil.”

Step 6:
Draw the finished “fossil” in your art journal. Label the drawing with information about the plant or rock.

Alternate project: Instead of using a natural material, choose an object that represents a meaningful event in your own life to turn into a “fossil.”

Inspired from a project on

Portland Public Schools art teachers developed this project for the HeART of Portland: A PPS K-12 Arts Showcase, which would have been held at the Portland Art Museum in spring 2020. The teachers took inspiration from the exhibition Volcano! Mount St. Helens in Art and from a project on, pictured above.