Draw out the design for your mask. Remember to include exaggerated expressions. It is also important to know what type of character you are modeling. Make sure that your model gets a good look at the drawing as she will be asked to hold her face in an expression as close to your drawing as possible.
Prepare the model's face by covering her hair with a disposable plastic shower cap and spreading a generous coat of petroleum jelly over the face, especially eyebrows and side burns. Any hair that the plaster dries to will be pulled out. Cut the plaster bandages into 1-inch-wide strips 3 or 4 inches long. Cut enough to make at least two full coats over the model's face. Instruct your model to make and hold an expression as close to the drawing as possible.
Apply the bandage to the model's face, overlapping each strip slightly. Apply the first coat up and down applying the bandage with the cloth side down and blending the plaster to create a smooth finish. Apply the second coat horizontally across the first layer. Allow the plaster to dry for 15 minutes, then work it loose from the model's face by pulling along the edges as the model scrunches her face. Tuck wadded newspaper into the back of the mask to help it hold its shape while it dries for 24 hours.
Add a coat of painter's caulk to smooth out any voids or edges on the surface of the mask. Use dampened fingers to smooth the caulk. Allow it to dry for two to three hours until it is completely dry to the touch. Layers of caulk can be used to build up areas such as eyebrows and lips to give a smooth, sculpted appearance.
Apply a coat of white semigloss latex to prime the mask surface. Paint on any design you like using acrylic latex paints. Unused house paint works well, as does acrylic craft paint. Hot-glue yarn, rope fibers or fake fur to the mask wherever you want hair. Poke a hole along the edge of the mask beside each eye and tie a heavy piece of cord to the mask for wearing.