Cosplay Props 101: Using Clay (polymer, foam, and paper clay)

clay 101 for cosplay props (paper clay, foam clay, polymer clay)

Clay is my favorite type of material to use for my cosplay props. It’s a beginner-friendly material, and it’s fairly cheap compared to many alternatives. You also don’t need to work with a pattern like you do with most other cosplay prop materials. In general, clay is also the best type of material to create organic shapes and textures (such as wooden props, antlers, or anything from nature).

Clay is great for beginners because if you make a mistake, it’s very easy to squish everything up and try again. It’s not like materials that need to be cut and glued together. Most types of clay are also non-toxic, so you can use them indoors. It’s also a material that can be created as its own individual prop, or it can be molded on top of other materials.

There are many types of clay you can use for cosplay, but the three that I’ve had experience with are paper clay, foam clay, and polymer clay. Each of these will be used in different circumstances, depending on the type of prop you are creating.

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Using paper clay for cosplay

Paper clay is one of my favorite materials to use for cosplay props (find it on Amazon). This kind of clay is great because it air dries, but you can also re-wet the clay to continue molding it. This means it’s great for any kind of structure that you’re building on top of another material that can’t be heated. It also means you’re not limited to just a few hours of working time and can work on molding your prop over the course of multiple days and weeks.

However, paper clay can be a little fragile. If you drop something made of paper clay, there is a good chance it will crack or break. It’s a little hardier than something like a ceramic dish, but you do want to make sure you’re careful with props made from paper clay.

Paper clay can be used for both small detailed props (like hair clips) and large props (such as staffs). If you use it for a large prop, I recommend creating a base shape with a filler material like styrofoam, cardboard, or aluminum foil. Then cover the base shape with a layer of paper clay so you can mold the details and easily paint it. This keeps the paper clay from becoming dense and heavy.

paper clay wand
Paper clay is especially useful for building on top of other materials, such as wooden dowels.

When to use paper clay

Paper clay is pretty versatile. You can use it for just about any kind of prop since it’s fairly lightweight and easy to use. In general, I would use paper clay when: 

  • When your prop is too large to fit in the oven. Any large prop that can’t be baked is a good option for paper clay.
  • When you need to build off of other types of materials. If you are building the head of a staff on a wooden pole or building off of a cardboard or styrofoam base, you can’t bake the prop. Paper clay can be used because it will air dry.
  • When you can’t finish the prop in less than 2-3 hours. Since you can add moisture to dried paper clay to make it moldable again, it’s ideal for making any kind of prop that will take multiple sessions to create.
paper clay staff
I used paper clay to mold the bird carving on the top of my staff for my cosplay. Underneath the clay is a base shape made out of aluminum foil.

How to use paper clay

All you really need to get started with paper clay is some water. When you take it out of the packaging, paper clay will be a little dehydrated and difficult to work with. You’ll want to wet your hands and knead the clay for a couple of minutes to get the water soaked through. Then you can begin molding it just like any kind of clay.

While you can do a lot with your hands, it is also helpful to have a set of clay tools available. You can use these to create detailed textures, roll the clay flat, smooth out the surface or add other details to the clay. Play around as much as you like until you find the tools that suit your purposes. The best part about paper clay is until you seal it with primer, you can always go back and redo anything you don’t like.

Using paper clay on top of a filler material. I often use paper clay on top of other materials, like styrofoam or aluminum foil. To do this, I will roll the clay out until it’s about ¼ inch thick, then drape it over the material that I used for the base shape. I’ll wrap the clay around the surface, molding as I go until it’s fully covered. Then I can mold any details on the surface of the clay.

Keeping the clay moist. If you need to continue working on paper clay props for multiple days, it’s best to leave a damp cloth over the top of the clay to keep it from drying out completely. It is still possible to give moisture to completely hardened paper clay and make it moldable again, but it takes a long time and a lot of water, so if you’ve got a project that requires more time, make sure to give the clay some basic moisture. If it’s small enough, you can even seal the clay in a container or ziplock bag to keep the moisture from leaking out.

The importance of priming your finished prop. After you’re happy with the shape of your clay, you need to let it dry completely and then prime it before painting. The primer will help to seal the surface of the clay so it won’t start to soak in moisture from humidity and paint. Adding 2-3 layers of primer can also help to add strength to the clay structure, making it a little let breakable.

How to make DIY paper clay

I will usually just buy paper clay to use for my props, however, it is possible to make your own at come (using paper!). If you need a budget-friendly clay to use, this is probably going to be the best option for you. Combine hot water and shredded paper and leave it overnight. Then stick it in a blender to create a paper pulp. After that, you’ll add flour and mix it together until you get a clay-like texture.

foam clay horn
Foam clay can be used on top of EVA foam to create a more natural or organic appearance. For example, you can create the ridges on ram horns with foam clay.

Using foam clay for cosplay

Foam clay is kind of like plastic clay (find it on Amazon). It’s a little rubbery and moldable, but when it dries it behaves similarly to EVA foam. EVA foam is a common material used for cosplay prop making. It’s excellent for making lightweight props, jewelry, and armor. However, the flat pieces of foam plastic are not great for creating organic, natural shapes. 

That’s where foam clay comes in. You can mold it on top of your foam prop to add details and build texture on top of the EVA foam base. After the foam clay dries it will still be able to bend along with the prop or armor underneath, but you will not be able to re-wet the foam clay to make it moldable again. Once it’s dry, you can’t go back.

However, foam clay is not as versatile as other kinds of clay. You technically can use it on its own to make small props, but it’s not the easiest clay to work with. It doesn’t stretch as easily as other types of clay and its rubbery texture makes it difficult to create detailed designs, but there is no substitute if you want to use it with an EVA foam prop. 

When to use foam clay

Pretty much the only time you need to use foam clay is when you’re working with EVA foam. Generally, it will be used to add texture to the surface of your props or armor. However, it can also be used to fill in gaps and smooth out ugly seams in the foam base.

scoring eva foam
To attach foam clay to EVA foam, score the the clay and EVA surfaces by creating many crisscrossing lines. Then add water to both side and press them together.

How to use foam clay

When working with foam clay, you will want to use water to make the clay more moldable. Keeping it moist will also prevent the clay from drying out too quickly. Once you’re finished, let the foam clay sit for 24-48 to dry completely before trying to paint or heat-form it.

Attaching foam clay to an EVA foam base. There are two ways of attaching foam clay to EVA foam, one while you’re molding the clay, and the other after the clay dries. 

  1. While you are molding the clay, you can score the surface of the EVA foam and the piece of foam clay on the spots they will connect (scoring means making many small crisscrossing lines). Then add some water to both sides you’re attaching and press the clay onto the foam surface.
  2. Alternatively, you can create your foam clay pieces separate from your EVA foam base and let them dry. Then glue them onto your foam to attach them after the fact.

Using foam clay with silicone molds. You can also use foam clay with silicone molds if you’re trying to get a specific shape. Simply press the foam clay into the mold, making sure to fill all the nooks and crannies, then allow the foam clay to dry. Afterward, you can glue it to your EVA foam base structure.

using polymer clay for small props
Polymer clay is best for creating small props and jewelry.

How to use polymer clay for cosplay

Polymer clay is a type of clay that needs to be baked to harden (find it on amazon). You can mold it as much as you want before baking, the clay will not dry out, but once you bake it, you cannot go back. Polymer clay also tends to keep a pretty smooth surface, so it doesn’t require as much sanding as other clays. 

On the other hand, polymer clay is quite fragile when making anything thin, and it can get expensive if you want to make any kind of large prop. You can easily get small amounts of polymer clay for less than $10, which is great for small projects. However, it can add up very quickly if you need to cover a large surface area.

When to use polymer clay

Polymer clay is best for making small props, costume details (like custom buttons and hair clips), and jewelry. Everything you make needs to be able to fit into the oven. You also should try to avoid making anything that’s more than 1-2 inches thick, since these can burn in the oven before they are ever baked through. 

Polymer clay can, however, be molded onto metal jewelry clasps and hooks and baked with the metal pieces. This makes it excellent for creating jewelry. 

If you don’t have a steady hand when painting, you can also get polymer clay in any color of the rainbow. You can create your cosplay craft with whatever colors you want right from the start.

examples of polymer clay
You can use different colors of polymer clay to avoid painting the small pieces after they’re baked. You can also use silicone molds to create detailed shapes with the clay.

How to use polymer clay

You can use polymer clay with your hands or using clay tools. When taking it out of the plastic, you may need to need it for a bit to make it more pliable. It’s best to use a silicone or wax sheet underneath your working area to keep the polymer clay from sticking to surfaces.

Baking polymer clay. You should bake polymer clay according to the directions on the brand of clay you bought. Typically this will be at around 275ºF for 30 minutes for every ¼ inch thick your creation is. Then you want to let it dry completely before adding paint or varnish.

Adding varnish to polymer clay. It’s best to use varnishes and sealants that are specially made to use with polymer clay. Many typical primers that are used with prop making react with the baking polymer clay to create a sticky surface.

Using foam clay with silicone molds. You can also use polymer clay with silicone cooking molds or resin molds. These can help you get specific or detailed shapes that may be difficult or tedious to mold on your own.

mixing polymer colors
You can combine colors of polymer clay like paint to mix different colors. Don’t forget you can also use black and white to make colors lighter and darker.

Mixing polymer clay colors

Polymer clays have the added advantage of being able to mix whatever colors you want. If you don’t have the color you need on hand, you can knead the polymer clay and mix colors together the same way you would with paint.

Simply take a portion of the two colors you want to combine and mash them together until you have a solid color. For example, combining blue and red clay will give you purple, and combining red and yellow will give you orange. It’s really useful if you need to create unique or specific colors.

Emily Joice

My name is Emily, and I have been Cosplaying Since my very first convention in 2008. Over the years I've learned a lot of new skills that have helped me become better and making cosplay and looking good for the camera.

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