Plaster of Paris is a powder made from calcium sulfate that forms a paste when mixed with water. The paste then hardens and can be used to cast items in a mold. In school, children often make dioramas, miniature representations of a scene, as a way of displaying what they have learned about a particular historical event or cultural society. Plaster of Paris is a useful, albeit messy, way of creating landscapes or casting small figures for a diorama.
Things You'll Need
- Shallow cardboard box or wooden platform
- Sponges or Styrofoam
- Thin sheets of cardboard (such as cereal boxes)
- Craft glue
- Plaster of Paris powder
- Paper towels
- Measuring cup
- Plastic containers, various sizes
- Petroleum jelly
- Drinking straws
- Ice cube tray or plastic shapes mold
- Poster paint
Landscaping with Plaster of Paris
Use sponges, newspapers and strips of cardboard to create the terrain for the diorama landscape. Ball up newspaper and stack sponges to create hills or mountains.
Create gentle slopes, river banks and waterfalls by bending strips of cardboard into the appropriate shapes. Lay out the terrain in a shallow cardboard box or on top of a wooden platform. Secure all the pieces of the terrain to the box or platform with tape and craft glue.
Cover the workspace and the floor with newspaper before beginning to work with Plaster of Paris. Cut paper towels into long, thin strips.
Prepare a small batch of Plaster of Paris according to the directions on the package. Stir carefully to remove lumps from the mixture. Dip paper towels into the Plastic of Paris mixture and lay them over the terrain to create a hard shell.
Work quickly, covering the diorama’s base with thin strips of paper towel soaked in Plaster of Paris. Allow the Plaster of Paris to dry completely before decorating the diorama.
Making Plaster of Paris Shapes
Cutting drinking straws into one- to two-inch-long pieces. Grease drinking straws with petroleum jelly.
Grease the sides of the ice cube trays or shape molds with petroleum jelly.
Prepare the Plaster of Paris mixture according to the directions on the package. Mix the paste in a plastic container. Stir carefully to remove lumps from the mixture.
Mix a small amount of poster paint into the Plaster of Paris mixture. Stir slowly to evenly disperse paint through the Plaster of Paris. Choose a paint color that is appropriate for the type of shape being cast.
Pour the mixture into the ice cube tray or plastic mold. Insert a piece of drinking straw into each section filled with Plaster of Paris. Be sure the straw reaches the bottom of the mold. Allow the molds to dry and use the straw to help remove the shapes from the mold. Repeat these steps for each new shape and color.