Costume Tutorials: Bone Mask
- Positive mold for your mask
- Plastic Wrap
- Clay Tools
- Friendly Plastic
- Heat Gun
- Fabric, Leather Straps, Elastic, etc.
- Paint and paint brushes
- Sealant Spray
- Heavy Duty Scissors
- Primer or Wood Glue
If you will be adding horns:
- Expanding Foam
- Cardboard or Foam Board
- Hot Glue
- Exacto Knife/Craft Knife
Step 1: Acquiring a Positive Mold
The first step is to acquire a positive mold to form your mask over. I used a combination of wire mesh and clay to sculpt one, but you can use an existing form as well if you have one. I sculpted until the mold looked pretty close to what I wanted my mask to look like in the end. It doesn’t need to be exact as you will be able to refine the shape and look of your mask later. Please note that if you plan on adding horns, or anything that will protrude significantly from the mask, it is a good idea to leave them off this initial mold as it will make it extremely difficult to pull your mask off if you add them now.
Step 2: Covering Your Mold with Worbla
Once you have your positive mold, cover it with a few layers of plastic wrap. The plastic wrap will keep the Worbla from getting stuck to your mold and make it much easier to pull off later. Once your form is covered, start adding your Worbla. I used nothing but scrap for mine, but you can also use a full piece. If you are using scraps lay the pieces over your form, overlapping them slightly, and press them down as you go.
Do this until you have a few layers’ worth of scraps on your mold. Don’t worry if your scraps go over the edge of the mold, you will trim that up later. If you are using full pieces rather than scraps, just make sure you are covering the entire mold, and use at least 2 or 3 layers, and take care to push the Worbla down into all the curves and crevices that might be on your mask form, especially around the eye holes. Make sure not to apply heat directly to your mold while the plastic wrap is still visible, the heat will rip holes in it, and you don’t want that.
Step 3: Smoothing
If you used scrap Worbla, the next thing you will need to do is smooth out any seams you might have. If you used a single sheet, you probably won’t have any seams to smooth so you can skip this step. Take your heat gun and apply heat directly to the mask. The plastic wrap will be safe under the Worbla now, so you don’t have to worry about that. Don’t be afraid to get it really hot, even if it starts to bubble a little bit. I would not usually recommend letting Worbla get hot enough to bubble, but it will actually make it easier to smooth out in this instance.
It would be a good idea to not touch the Worbla directly during this step, as it can get hot enough to burn you. Instead, dip a spoon in some water and use it to smash all the seams flat. You will have to get the Worbla really hot and push really hard if you want to get rid of the seams completely, but since this mask is meant to resemble bone, having a few lines left over isn’t going to hurt. You can also use clay tools to help you get the Worbla to shape to the form properly if you have any small cracks or other details you need to get the Worbla into.
Step 4: Removing and trimming
The next step is taking the mask off the mold. If you used enough plastic wrap, you should be able to pop the mask right off. Use this time to also trim up the inside of the eye holes.
Next, trip up the edges of your mask into the right shape. Also use this time to try it on and see if it actually fits your face. You can still heat up your mask and reshape it if you need to, just be careful and use a lower heat setting so you don’t accidentally cave it in.
Step 5: Adding Horns and Things
Now is the time to add on any details that weren’t on your original form. If you want to add horns, start by cutting the shapes for them out of foam board. Cardboard would also work for this step. Position them on the mask and then glue them on with hot glue.
After that, cover the foam board with expanding foam and let it cure. The brand I used is called “Great Stuff.” Make sure you are working on a surface that can get messy, because expanding foam does not come off anything it gets stuck to. When the expanding foam is completely cured, it should have expanded to about double its original size. It normally takes a few hours to cure, but you can speed up the process by spraying it with some water. To test it, stick a knife into it. If it comes out clean, its done!
Once it is completely cured, just carve the shape of the horn with a craft knife.
Next, it’s time to cover the horns with Worbla. I used smaller pieces of scraps for this, and built up around the base to give it a smoother transition. Do not try to smooth the seams out the same way you did for the rest of the mask. The expanding foam at the center of the horns is too soft, so doing so would just crush them. Just leave them as they are for now.
For my mask, I needed to add on a small detail at the sides, sort of like a jaw bone. I simply cut the shape out of a double-layer-thick piece of Worbla and attached them onto the mask with heat.
Step 6: Friendly Plastic
At this point, It is time to switch over to Friendly Plastic. If you are not familiar with it, Friendly Plastic is also a thermoplastic (like Worbla) but it comes in pellets rather than sheets. It is much easier to sculpt with than Worbla, and it is perfectly smooth when you’re done. However, it cools down much faster so you have to work fast or keep heating it back up. To heat Friendly Plastic, I use a bowl of hot water. I boil the water in a tea kettle, pour it into a bowl, and then pour in some Friendly Plastic pellets. Once they are all gooey, I scoop them out with a spoon and start working. You can use Friendly Plastic to easily smooth out the horns and to build up the mask anywhere it still needs some added shape. For example, the jaw bone piece and around the eye holes on mine. To shape it, use your heat gun to reheat the plastic once it is on your mask and use a combination of fingers and a spoon dipped in water to smooth it. With enough heat and pressure, you can make a perfectly smooth transition between the Worbla and Friendly Plastic.
Once you are done smoothing your Friendly Plastic, you can easily add in any extra details you might want. I added cracks around the eyeholes and at the base of the horns by simply heating the plastic back up again and using a clay tool dipped in water. I also added the ribbed details on the horns just by heating the plastic and shaping them with my fingers.
Step 7: Adding Straps
Now its time to make your mask wearable. You might need to add some cushioning to the inside so it sits up right. This will also help make the mask more comfortable. Just put the mask on your face and decide where any cushioning might need to go to make it sit where you want it to. The cushioning I used was regular cushion foam you can buy at any fabric store, but EVA foam would also work well. I added some on the forehead and under the eyes. To attach, I used hot glue.
Next is to devise a way to attach the thing to your face. I took some more Worbla scraps, made some little loops, and pressed them onto the inside of the mask at the top.
Then I strung a strip of fabric through them and tied off the edges so they wouldn’t pull back through. I then strung another strip of fabric through the first, and wrapped it through my jaw bone pieces. You can use a number of different things (leather straps, elastic, etc.), but fabric worked well for mine. Depending on what your mask looks like, you might need to get creative to make sure it stays on your head.
Step 8: Priming and Painting
The last step is to prime and paint your mask. Wood glue makes an excellent primer for Worbla and Friendly Plastic and can easily be sanded to make your finished piece extra smooth. To create the look of bone, I used a combination of white, black, red, yellow, and blue acrylic paints.
I started with a base coat of pure white, and used the red, yellow, and blue to mix various shades of browns and yellows to give it a dirty, grungy look of weathered bone. Remember, the deeper areas of the mask should be darker, and the higher areas of the mask should be lighter. Every few layers of color, I would also add in more white on top to help the colors blend. I also made sure to darken the eyeholes and any deeper cracks or crevices with black to give it depth. You’ll need to experiment to give your bone mask the look you want.
Once you are satisfied with your paint job, just add a protective sealant spray and you’re done! Since it is meant to look like bone I would recommend a matte finish, as anything glossy or satin might not look fitting on dusty old bone.