Plaster Nature Collage MAterials: - heavy paper plates - collage items from nature (shells, small stones, leaves, pinecones, dried berries, etc) - plaster of paris - water Method: Collect collage items from outside. Have a big person help you mix enough plaster of paris to fill a plate. Pour 1/2" from top. When plaster sets slightly, arrange materials on top. Peel plate off when completely dry.