Latex masks usually begin as sculptures made of oil-based clay. The designer starts with an armature of a human head, to which he or she applies clay in order to rough out the general shape of the mask. Once the rough shape is established, the designer uses fine sculpting tools to shape the mask.
Once the sculpture is finished, it is turned into a mold. This is done by applying an industrial gypsum over the sculpture in order to create a perfect but reversed copy of the sculpture. Before the gypsum is applied, the designer places a dividing wall around the sculpture's middle, so that the resulting mold will have two halves. Once the gypsum dries, the designer removes the two halves and cleans the clay off.
To cast the mask, the designer connects the two sides of the mold and pours a special form of latex called slush latex inside. After a short wait, the designer pours out the excess liquid. The latex that remains inside will dry into the shape of the mask.
To paint the mask, the designer usually uses an airbrush, usually with a specialized type of latex paint. The designer applies a base coat first, which will be the overall color of the mask. Next, a shading coat goes on the lower points on the mask's surface and a highlight coat is applied to the higher points. Eyes, teeth and other details are painted using finer brushes. A specialized varnish is applied last.
The different parts of the masks will have seams showing where they connect. You can remove any sign of the seams using a solvent such as Bestine or Hexane, a Q-tip and a Dremel, a high-speed rotary tool, with a cotton bullet. First apply the solvent to the seam, and then buff it down with the cotton tip. Work the Dremel in the direction of the least resistance first, then change directions. Then clean it off with the Q-tip again.
Latex masks will not last forever, but there are things you can do to maximize their lifespan. Masks last longer when they are protected from perspiration, sunlight and heat. In addition, keep them away from any type of petroleum, which will dissolve latex.