Foam Latex Research

Foam latex is a popular from of prosthetic appliance because it gives a high amount of performer comfort. Materials such as silicone do mimic the texture and appearance of human skin a lot more realistically, but silicone has no breath-ability and an actor wearing silicone appliances will perspire a lot under the prosthetics when worn for an extended period of time. Gelatin, being another option, may start to melt. Foam latex is also a lot lighter than the other two options so a full-face appliance will likely weigh less than an ounce and when applied, it is almost undetectable by the actor wearing it. Although foam latex is the lightest and most comfortable appliance to wear, it is probably the most difficult material to work with overall.

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Problems

- Foam latex is opaque. Silicone and gelatin can be coloured intrinsically to be semitransparent or translucent, similar to real human skin. Therefore to create the idea of translucency, the appliance has to be painted with numerous transparent layers of pigment, most often with an airbrush, to look like real skin.

- Foam latex requires a heat cure in an oven and it can't be a normal kitchen oven.

- Foam latex gives off toxic fumes during the heat cure

- Foam latex is time and temperature sensitive, meaning it has to be watched closely, can go wrong very easily and can turn out different between each batch.

- Foam latex can shrink, the thicker the foam the more it shrinks

- Foam latex is delicate so rarely survives removal in one piece at the end of the day meaning there needs to be fresh appliances every day for the performer.

History of Latex

- Latex is a natural liquid that comes from the hevea tree grown in Malaysia, Thailand, Indonesia and the Philippines and other tropical countries

- The tree is tapped and a small amount of latex (a few ounces) is collected from each tree before the cut on the tree congeals and heals itself. Each tree is only tapped once every two days.

- Over 95% of all natural latex is concentrated by a method called centrifuging. The result is a high quality product containing 60-65% solids.

- The remaining latex, which is less than 5% of the worlds production, is concentrated by another method called creaming were ammonium alginate is added to the raw latex, causing separation. The watery 'serum layer' is drained from the vats, leaving a higher concentration of latex.

- As latex is a natural product, its composition is dependent on different environmental conditions. The hevea tress and the latex are affected by how much rainfall there is in a given season, how many sunny days, how young the tress are etc. Therefore the quality of rubber varies from season to season, year to year and month to month.

- These fluctuations can be very difficult for makeup effects because the latex will behave differently every time. For this reason when GM foam purchases creamed latex it calibrates its own latex base. It adjusts the pH balance, then conditions the latex with additives and finally makes a special blend with other types of latex. This means GM foam can carefully control the cell size, foam volume, flow and gel time.

Debreceni, T (2009) Special Makeup effects for stage and screen. Oxford: Focal Press (pg. 169-72)