By: Kendra K.
Hello everyone, I am here to talk about a now-common material that many cosplayers use: EVA Foam!
EVA foam is a light-weight, durable, and cheap foam material, which can serve as a great alternative to other materials, such as Worbla (a thermoplastic used often for props and armor). Foam can be used for armor pieces, props, and more: the possibilities are as endless as your creativity! If you make sure to work carefully during the building process and cast a careful eye to painting, you can achieve really clean finishes, mimicking the look of metal or other interesting textures. EVA foam comes in a variety of sizes and styles, so make sure you do a bit of research before you dive in!
There are three main different types of EVA Foam:
- High Density
- Floor Mats (diamond or cross pattern)
- Craft foam
For the following build, I am using a high-density foam which comes in a variety of thicknesses. Floor mat style foam and craft foam, generally are available in limited sizes, but can serve their own purposes. Just keep in mind that floor mat foam is thicker and sturdy, while craft foam is thin and great for detailing.
I find the best way to tackle a new project is by drafting up patterns. Paper patterns can help you come up with a shape, and when you cut it and lay it flat, you will find that foam is flexible to creative a huge variety of different shapes to suit your needs.
I just mocked up two patterns where you can see the use of darts and odd shapes. Another advantage of using patterns is that it allows you to map out where you want to cut in order to save material for future use.
The easiest way to go about cutting the foam is using a sharp X-Acto blade. The foam is relatively easy to cut through by hand, but the blade can dull quickly. Regularly switching to a new blade may be needed to make your life easily and ensure your foam has a clean cut.
Alternatively, if you have access to power tools, you will find foam is very quick and easy to slice through. I personally use a band-saw when I need multiple pieces to be identical, as I pin several layers together. Just remember to get supervision if you are new to power tools!
See below for the different results of different tools and blades:
For further shaping, you can cut the edges on an angle in order for pieces to lay fatter against each surface. This can also help you achieve a desired shape and appearance.
For the next step: glue. While many cosplayers would consider the hot-glue gun to be the best friend of the craft (and it is), you’ll get the best results with EVA foam by using contact cement. Contact cement helps create a permanent bond that is still flexible and is relatively fast drying. You can pick this glue up at most hardware stores.
When working with contact cement, you will need to make sure you are protecting yourself properly. Make sure you are using a quality respirator and working in a space with good air flow, as the fumes from contact cement are toxic.
To apply the glue, you will want to brush on a thin & even layer that covers the surfaces you wish to attach and wait 5-10 minutes for it to dry (read the instructions on your bottle of contact cement!). When the surface is no longer tacky, that is the ideal time to press the glued edges together. If you don’t wait long enough, the glue will still tacky and that can prevent the edges from sticking.
Keep in mind that contact cement is not forgiving, so there is little room for error once both surfaces have dried sufficiently and are touching. You will need to be extra careful at this step.
To finish off, the last important tip I can give, is to remind you to carve the foam to smooth out your desired shape. This can take some practice to get the hang of it, so feel free to practice on scrap pieces. The simplest way to carve your piece is going back to your trusty X-Acto blade and cut the foam in small pieces, building towards the end result.
The foam can be sanded as well, which will reduce any bumps or rough areas that need to be fixed. You can sand by hand or by using a dremel (I highly recommend a dremel, as it saves a lot of time, protects you from pesky hand cramps and gives a great result).
Once you have your desired look, you will finish off this part of the project by heat sealing the foam. To do so, you will need a heat gun or another high temperature source. This closes the cells in the foam that you may have created through the cutting and sanding process. Heat-sealing foam is important as it adds the final step of smoothing the surface, which is key if you continue to seal and paint the foam.
Many cosplayers prefer this material over other types, as it is lightweight and relatively inexpensive, but each technique has their own advantages. I hope you feel you better understand EVA foam and feel equip with a few techniques to help you get started, armed with this bit of insight on EVA foam.
Good Luck and Happy Cosplaying!