Liquid latex is a mixture of natural latex rubber and ammonia that comes in liquid form and dries into flexible, stretchy rubber. Perhaps the most common and well-known commercial application of liquid latex is its use in theatrical effects. Liquid latex has a wide variety of uses in make-up and special effects, ranging from simple wounds and gluing to complex prosthetics capable of transforming an actor's experience.
Latex serves as a glue for prosthetic make-up pieces (e.g., fake noses and ears) that is flexible and dries quickly but is easier to remove than spirit gum, the other leading prosthetic glue. To use, simply coat the underside of a prosthetic piece in a layer of latex for a secure hold, or space out a few dots of liquid latex on the piece for a light hold and easy removal. The only problem with this use of the latex is that the latex will build up over time on porous pieces, so it's not as good for long runs of a show unless replacements are made regularly.
Stippling is a technique that uses latex to create the effect of wrinkled skin. If done well, it looks good enough to stand up to the scrutiny of a movie camera or close photography. To create stippling wrinkles, stretch the skin with your fingers, then apply a thin coat of latex to the entire area. Do not release the skin until the latex is dry (this takes a couple of minutes) and you have coated it with powder to keep it from sticking to itself and peeling. When released, the skin will have fine wrinkles. Apply make-up over the top of the latex.
Use latex to create large skin wounds that you can peel off and reuse. Soak strips of paper towel or toilet paper in latex and lay them on the skin. Arrange them in the shape of a wound (this is not difficult; they will naturally look wound-like) and let the latex dry. Finish the wound by dabbing thick stage blood into the recesses of the latex wound. If you like, you can also make a paste of black food colouring and flour and dab it into place to look like dark scabs or burn marks. Be sure to prepare the skin by greasing it with petroleum jelly and shaving hair, if possible. Otherwise, removing it later will be painful.
Latex casting is done by pouring liquid latex into a mould and letting it set, much like using a gelatin mould. The finished product will be smooth yet flexible and stretchy. For stage make-up, artists create their own moulds by taking a plaster cast of an actor's face, building the desired features on the face in clay, then making a negative impression (a new cast) of the clay pieces.
Sculpting with liquid latex is much like doing paper mache art, only with latex in the place of wheat paste and gauze or paper towel in the place of newspaper strips. Dip strips of paper towel in latex, then wrap them in layers around a mould to create a sort of "sock" in the shape of the mould item. Mold items can be made in any shape and size. As long as they are non-porous or wrapped in a non-porous material (such as kitchen cling film), the latex will peel away cleanly.