Plaster of Paris is an excellent material to use for making masks. Take an afternoon to make a mould of your face and you can have it to display, or pour clay into it to make a smooth mask to paint and wear. Plaster of Paris has been used to make masks for children as well as adults. While it may sound scary at first, it's never as scary as it first seems. You will need a friend to apply the mask for you.
Wait for a sunny day and bring all your materials outside. Set up a lawn deckchair to lie in while the sun dries the mask. Wear old clothing.
Tuck your hair into a shower cap. Coat your face with petroleum jelly (vaseline). Use a lot of petroleum jelly and coat your eyebrows and eyelashes thoroughly to keep the mask from pulling out hairs.
Cut a drinking straw into 7.5 cm (3 inch) lengths. Lie back on the lawn chair and put a 7.5 cm (3 inch) long drinking straw into each nostril so you can breathe through your nose.
Mix together 474 ml (2 cups) of cold water and 652 g (4 cups) of the plaster of Paris in a bowl. Stir the mixture until it is thoroughly mixed, and use a spatula or other large flat, plastic item to begin spreading the plaster of Paris. You'll need a friend to do this for you, since you can't apply the mask to yourself.
Cover the entire face and add plaster of Paris until the coating is even. Have two or three people move the lawn chair with the person in it into the sun if they are not sitting in direct sunlight.
Allow the plaster of Paris to dry for 20 minutes. Don't worry if it starts to feel warm. It will cool down again quickly. Do not move your face or the mask may crack and break.
Sit up and carefully pull the mask off your face. Move your face around by wiggling your nose and lips to help it come off.
Take out the straws and fill the inside or outside of the nose of the mask with plaster of Paris, if you wish to plug the holes.
If you need to remove the mask before it's finished, just sit up and pull it off. Wiggle your mouth and nose to help the mask break free.
Do not try this if you have any facial hair, such as a beard; it can pull your hairs out.