Apply petroleum jelly to any exposed facial hair on the model. Cover hair on the top of the head with a bald cap or plastic bag.
Fill the water container with warm water and place it next to the model.
Set up your work area. Lay down a drop cloth to catch any plaster droppings and place your bandages and scissors close to the model.
Ask your model to sit on a stool or chair in front of you; the model should remain seated during the entire process.
Cut off two pieces of plaster bandage at the same length using the scissors. The bandage length can vary; it depends on how much of the head you want included in the final cast. Set one of the bandages aside to use on the front. Dip the other one into the water, wringing out any excess liquid. Lay the wet bandage horizontally across the top of the head, from ear to ear and extending down the neck to the shoulder on each side.
Cut and wet a second piece of plaster bandage. Use this piece to connect one end of the first bandage to the other across the shoulders.
Apply additional plaster bandages vertically to cover the back of the head, filling in the empty space formed from the first two bandages. Continue until it is three to four layers thick.
Apply petroleum jelly generously to the entire front edge of the back casting once the cast hardens. This area goes from behind one ear to the other across the top of the head and extends to the end of the cast. The petroleum jelly-covered area should extend one to two inches from the front edge of the cast and cover only plaster bandage.
Dip and apply the bandage length you cut before beginning the back casting across the top of the head, covering the entire petroleum jelly-coated area. This bandage should not come into contact with any part of the back half that is not covered in petroleum jelly.
Use a second piece of bandage to connect one end of the front half bandage to the other across the front of the upper chest, even with the bottom of the back casting. Use additional bandages to fill the front in a horizontal pattern, covering the face and neck. Leave the nostrils uncovered for breathing.
Wait until the front half dries. Run your fingers under the area where the front and back half overlap until the seam loosens. Remove the front and back half of the cast from the model's head.
Reassemble the front and back half of the cast along the petroleum jelly-covered area. Use a length of plaster bandage across the top of the head to connect the halves. Once dried, the empty cast will be ready for any desired finishing work.