Lightweight and soft, yet capable of realistic organic detail, foam-filled latex props are a popular item for theatrical events, costume play and Halloween decorating. You can build your own latex and foam props using one of two methods, whether you're looking to make filled casts of existing shapes or carve your own directly from upholstery foam.
Build moulds for your latex by creating shapes (such as body parts, dead animals or creepy insects) from modelling clay. Cover the clay in a tightly wrapped layer of plastic cling wrap.
Spread latex on your mould using the disposable brushes. Apply an even, consistent coating of liquid over the mould's surface.
Allow latex to dry and add additional layers. Drying time will vary according to thickness, but allow at least an hour. Latex is fully dry when it has changed uniformly to a darker shade. Add coats until the rubber is about 1/8-inch thick in order to ensure that the latex keeps its form and texture. Turn the form over to coat the bottom in the same manner (if applicable).
Remove the finished latex sheath. Cut a slit along the edge of the latex using scissors, opening it up just enough to be able to pull it off the model form; it will peel cleanly away from the cling film.
Fill the hollow latex shape with foam. Shred pieces of upholstery foam with scissors into pieces both small enough to create small details on the prop and large enough to fill the bigger sections. Push the small pieces into every nook and cranny and try to fill the shape as tightly as possible.
Seal the open edge of the prop by using more liquid latex as glue. Let dry. (You can reopen, restuff and reseal in the same manner if the contents of the prop settle over time.)
Decorate and colour the finished prop. Use only a high quality acrylic paint (other paints may react with the latex or flake too easily). For blood, use a clear red glass-painting acrylic.
Carve a prop of the desired shape in upholstery foam using sharp, serrated knives.
Coat the foam shape with the liquid latex using the disposable brushes. Allow each layer to dry fully before adding the next. Add enough latex to fully obscure the texture of the foam.
Decorate the dried latex prop with acrylic paint. Add any surface detail and colour desired.
Avoid getting latex on any porous surface, as it cannot be cleaned once it is dry. Latex will pull cleanly away from most non-porous surfaces. Cap your latex bottle immediately after use to prevent its hardening in the bottle. Use only disposable brushes with latex.