Foam rubber is what often lends shape to costumes. It is very useful and an easy material to work with. This page provides some general information about foam rubber.

Types of Foam

The foam I use in fursuiting is the same stuff which is used in furniture and packing material. But there are many different varieties of foam; depending on what part of the costume you are developing, you may choose certain types of foam. Most commercial foams are made from polyurethane rubber. The differences in foams is usually in the density of the foam, as measured in pounds per material cubic foot.

When working on body padding, I like to use a medium-density open-celled polyurethane foam. This is the sort of foam which is found in cushions; because of this, you can usually find sheets of it at larger fabric stores. This foam is somewhat soft and pliable, often yellow in color. (It yellows from ultra-violet exposure; eventually, usually after several years, the foam begins to become brittle and break down.)

This foam is sometimes too soft and rubbery to carve, but it can be cut into the necessary shapes with a pair of sharp scissors (Fiskars). When used as part of a muscle suit, the foam flexes pretty well in response to the movements of the wearer.

For something like head carving, you will want to use a more rigid foam. I've had good luck with a close relative of the gray anti-static foam used to ship computer components. It is stiff enough that you can use an electric carving knife to shape it; I wouldn't want to try to sculpt a foam head with only scissors!

These are both open-cell foams. Closed-cell foams are less flexible and denser, in general. Neoprene rubber (the stuff used for wetsuits) and styrofoam are examples of closed-cell foams. The only such foam I've had occassion to use is one that is sold in small colored sheets as Fun Foam.

Working with Foam

Foam can be cut into pads to add extra shaping to a bodysuit. Heads can be carved from solid blocks of foam. Sheets of foam can be cut into patterned pieces and glued in order to create three-dimensional structure. There are lots of ways to use this stuff! All I can do is offer some tips:

When attaching fabric to foam, I've had the best luck with spray adhesives and hot glue. Heavy adhesives like epoxy will end up tearing the foam, because they don't penetrate and flex with it. Sewing to foam can result in the foam tearing along the sewn line.

However, if you want to get a really secure seam between two pieces of foam, there are specialized glues for the task. They are generally only available in larger quantities, though. One that is available and is very effective is Fastbond 100 from 3M.

Foam needs to be cut with heavy-duty scissors, such as Fiskars. Foam can also be cut with an X-acto knife, but it will quickly dull the blade. So, unless you only need to cut a small amount of the stuff, I'd stick to scissors. Cutting foam requires applying a fair amount of pressure, so be sure that the scissors are comfortable or you may get some blisters!

Polyurethane foams will deteriorate with age. This is simply due to exposure to air and ultra-violet light; it's not a process that can be easily stopped. Because of this, expect that items made from foam will start to lose their rubbery flexibility after two or three years. The foam will still be usable for quite a while beyond that before it begins to lose structural strength. The lifespan of foam is generally long enough that it's not a serious issue for fursuiters.