Defined as "a common material used to construct prosthetics. It involves a latex base, a foaming agent, and a gelling agent. Standard foam latex must be cooked in an oven in order for it to set." I will not be able to work or experiment with foam latex during my Advanced Makeup course,so instead I did some research and have compiled basic information useful when working with foam latex.
When doing research for various projects I have found the FX Wikia community to have some helpful, concise information. I have also used more books for this project than I normally do, I find that sometimes material and information is hard to find online but books can offer something of a foundation. For my foam latex research I found The Techniques of Three-Dimensional Makeup by Lee Baygan at my university's library. This was the only text that had information about foam latex.
I have found it somewhat difficult to find precise information as to how to use foam latex because I think a lot of the process is specific to the brand/type of foam latex that you are using and instructions come included with those products, but the Monster Makers have a fairly good step-by-step for making latex masks, but the general concepts are the same. They also sell kits for working with Foam Latex. FX Warehouse is another good source for any/all supplies needed for makeup purposes.
The first step is to make a sculpture out of clay. This can be done on a flat or rounded surface, or you can use a life cast to sculpt on. Monster Makers suggests using oil-based clay (probably because it does not dry out).
The next step is making a mold from the clay sculpture. The first part of this process involves creating a dividing wall around the sculpture; If you are creating a mask that goes all the way around the head, you should pick a place where the mold will split in two. If you are creating a mask similar to the one above you should only need to create a dam for the plaster.
Once the dams or dividing walls have been created, mix and pour your plaster. You can use industrial gypsum as Monster Makers suggests, or another product of equal durability. When the plaster has fully cured and dried, separate the pieces and clean out the mold, remove any clay that is inside.
Then, an optional skin of liquid latex is applied into the mold by coating the mold with latex or by pouring a large amount of latex into the mold and then pouring off the excess.Next, the two pieces of the mold should then be bound together for the pouring process. If you are using a life cast, the "head" should go inside the mold so it can form the inside of the mask. Molds should also be prepped with mold release (specific to your brand of foam) prior to mixing the foam latex.
The next step, mixing and pouring the foam latex, depends a lot on the specific instructions to the supplies that you are using. I found a PDF of the Monster Makers instructions for pouring/running the foam latex, but again, the instructions will vary from product to product. Once all the parts are carefully measured and/or weighed, mixing can begin. Most sources suggest using an elecrical mixer for better consistency. Finally the molds can be filled. This should be done carefully to make sure the foam runs into all the deepest parts of the mold. There is an alternative method of injecting the foam into the mold through an escape hole (better for LARGE molds) created during the mold-making process. Once poured, the pieces of the mold should be held together tightly by standing on them or pressing down with your hands while jelling, the first step in the curing process. You will know if your foam has jelled by poking some of the protruding foam with your finger - if your finger leaves a deep impression and no liquid comes out, the foam has jelled.
Once jelled, most foam latex also requires being baked at a low temperature (Monster Makers says 160 degrees F) to cure although some products such as Kryolan's two-part cold Foam System do not require baking. One source, Makeup FX suggests using an oven that is dedicated to this process and will not be used for food.
You can also buy foam latex appliances from costume/makeup sources such as The Grimm Brothers, Mostly Dead, and the FX Warehouse.
The application process is similar to the latex, gelatin, and silicone processes I have been working with. The appliances can be glued to the model with various materials including spirit gum, liquid latex, and pros-aide. After the piece is applied, some sources suggest coating the appliance with a thin layer of liquid latex. The piece can then be powdered and makeup can be applied.
For more information you can search any of the links provided in this post or check out other online sources such as the Stan Winston School of Character Arts which has some helpful videos and tutorials. You can sign up for a free trial before giving money to the program or you can simply buy their dvds or a digital copy of the videos.