1. Using a reference guide with visual samples of a variety of petroglyphs, have students draw the image using black glue. They can draw extra details such as dots, designs and any additional symbols using the black glue.
2. As soon as they finish their black glue outline, they can sprinkle some coffee over the surface of the rock, making sure that the glue areas are covered in the coffee.
3. Let dry and brush off any excess coffee from the surface using an old toothbrush.
Black glue ( I mixed Elmers glue with black tempera paint or you can use the ready made black glue), rocks, petroglyph images, ground coffee, toothbrushes.