Gypsum plaster is usually called "plaster of Paris." Gypsum plaster was an important commodity in Paris for centuries because Paris is built over gypsum beds. Gypsum and lime plasters were used to stucco the exteriors of peasant huts, Mayan temples, the pyramids of Giza and most of medieval London, but now most exterior plasters are made of concrete. Gypsum plaster is usually applied over chicken wire "lath" in interior walls or, often, over a chicken wire "armature" to create sculptures or model landscapes.
Staple chicken wire to a wooden frame (armature) if you are making a model or sculpture. Staple the chicken wire to plywood, wood lathe or other base wall material.
Chuck a paint mixer attachment to an electric drill. Measure 6 cups of water into a large bucket.
Put on a dust filter face mask. Pour 5 pounds of plaster into the water.
Mix the plaster for three to five minutes using the paint mixer attachment and the electric drill.
Apply the plaster mixture for walls over the chicken wire with a plaster trowel. Hold the trowel at about a 30-degree angle. Cover the chicken wire with about 1/16 inch of plaster.
Dip burlap strips in the plaster mix if you intend to make a model or sculpture. Lay the burlap strips over the armature and smooth the finish with a paint brush or your hands.
Allow the plaster to dry.
Apply a second coat of plaster to walls holding the trowel at a 75-degree angle. Ensure that all chicken wire is covered and overlap trowel strokes to eliminate edge marks. Allow plaster walls to dry for at least one day before painting.