Another material that's making waves in the Cosplay Community is EVA Foam Clay. Flexible, light, and non toxic this material makes it possible to sculpt accessories or add flexible details to props without sacrificing the weightlessness of foam.
One of the best things about Foam clay is that you don't need fancy tools to use it. The most you'll need is a small cup of water and a paintbrush. I use silicone tipped sculpting tools for fine details and blending. that's it!
How do you work with it? The key to working with EVA foam clay is to keep it wet. If you are using a base of some sort, make sure you wet it first. this helps the foam clay to stick to it. From there just periodically brush on some water to keep it malleable! For a small demonstration of this technique check out my prop tutorial video here.
Other ways to use Foam clay include:
Pressing into molds: Foam clay can be pressed into silicone molds. This method requires patience though! You may need to wait a few days for it to cure completely before you can safely remove it from the mold.
Using it as a gap filler: Foam clay can be pressed into gaps or holes in builds. After it's had time to cure, it can be sanded down, carefully.
When working with your foam clay remember that while it does dry into EVA foam it should be heat treated with caution. If heated for too long it can bubble and blister.
What Kind of Foam Clay is Best?
As with most materials the best kind of foam clay is dependent on the user. There are now many different brands of foam clay on the market with a range of prices (to include a line of High density foam clay on Amazon). It may take a bit of shopping around to find a brand with a consistency that you enjoy working with.
Where to Buy
In the US, you can now find tubs of white foam clay in Michael's craft stores. Price range wise, it's usually in the middle around $14.99 per 300g tub, with the added bonus of immediate availability for the most part. Most online suppliers now carry a brand of foam clay as well:
Coscom Cosplay Supplies ($11 for 300g)
Lumin's Workshop ($13.90 for 300g)
SKS Props (Blick Art supplies) ($16.19 for 300g)
Cosplay Shop ($17.02 for 300g)
TNT Cosplay Supply ($17.95 for 300g)
My personal favorite so far is Lumin's Workshop's line (and it has more to do with the texture than it does the free mini pack of gummy bears they send with every order). You can also find some fairly decent foam clay on Amazon in a pinch.
Making Your Own!
If you are adventurous you may even want to try making your own foam clay at home!
If so you can check out Ben Eadie's video for the recipe and instructions!
Advantages and Drawbacks
EVA Foam clay is great. It's light weight, flexible and non toxic. It can be sanded, bent, delicately heat shaped, and works well with all the typical adhesives. Unfortunately, as with most materials, there are drawbacks.
Foam clay will eventually become brittle and crumbly once it's dried out completely. It also cannot tolerate the same amount of heat as regular EVA foam can without bubbling up.