Place the face form on a flat surface, such as a table or workbench.
Cover the face form in modeling clay. After you have covered the head up to the back of the crown with clay, begin to sculpt and form the face into the clay. Make holes where the eyes of the mask will be located so that you will be able to see through it. Put in all the details your design requires during this phase of the process.
Apply a coat of clear water-resistant protective spray to the clay mask mold. Allow two hours for the coat to dry and apply a second coat. Repeat this step using a dull-finish spray. This step will prepare the mask mold and help the plaster used in the following steps to have a smooth finish.
Pour some plaster mix into a plastic bucket, along with water. Mix the ingredients. Use a paintbrush to apply a layer of plaster to the clay mold.
Let the plaster dry for about an hour. The drying time for the plaster is largely dependent on the temperature of the room in which the mask is being made. Make a second batch of plaster that is a bit thicker than the original batch. Apply a second layer of plaster to the mask, making the entire mold roughly 1 to 1 1/2 inches thick. Let the plaster mold dry for 24 hours.
Pull the mold off the face form and remove the clay from the inside parts of the mask mold. Pour liquid latex inside the mold, making sure the open end (which will be where you put your head into the mask) is covered with plastic wrap to prevent it from being closed up as you pour the latex.
Allow the latex to sit in the mask mold for one to two hours so that the latex begins to form the mask. After the latex has had time to sit, pour out the leftover latex into a container. Allow the remaining latex that has formed to the mold to dry for three to four additional hours.
Remove the rubber mask from the plaster mold. Use a pair of scissors to cut out the eye and nose holes. Color the mask and make the detail more elaborate by painting it. Use paint that is compatible with latex material.