<p>If your model is hollow but able to hold its own shape, you could use an expanding foam to fill it in order to make it solid.</p>
<p>Be extremely sparing as if you use too much it could burst out of the seams.</p>
<p>From context you seem to know your way around 3D modelling software, so you could simply make a crude version of your mask in the software and then ask someone at your nearest makerspace to help you to 3D print it, and then wrap the foam around the 3D print as a surface finish.</p>

CC BY-SA 4.0
2023-05-15T12:21:18.360Z
I think a 3d-printed form is the way to go.  It doesn't have to be printed in one piece (you'd need a big printer).  You could use PLA (which is often the first choice of filament), even if heat-forming the foam over the top, as EVA softens quite a lot cooler than PLA.
Chris H
CC BY-SA 4.0
2024-04-19T22:16:46.213Z
@ChrisH This would make a good answer. I don't know much about 3d printing, but the contour lines from the 3d image above look like a great starting point for a basket armature.
rebusB
CC BY-SA 4.0
2023-05-14T15:17:15.597Z
2023-05-14T15:17:15.597Z
Aaargh Zombies
<p>This video contains a similar project to make horns from EVA foam, including methods to make it sturdier.</p>
<p>Their primary method is to use layering\laminating, and to ensure that the seams are solid. Overall, their process is optimized for strength.</p>
<p><a href="https://www.youtube.com/watch?v=2sCRCFy5Nbs" rel="nofollow noreferrer">https://www.youtube.com/watch?v=2sCRCFy5Nbs</a></p>

CC BY-SA 4.0
2024-04-21T06:55:05.310Z
2024-04-21T06:55:05.310Z
Aaargh Zombies
<p>I made a plan for my mask to make a template pattern out of in a 3D modeling software, as seen below. The blue model is for scale.</p>
<p><a href="https://i.sstatic.net/NDM5h.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/NDM5h.jpg" alt="![A 3D model of the mask I plan to make, with a picture of its planned pattern on the side" /></a></p>
<p>It's pretty big, and the only foam I have right now is 2mm thick, so I'm worried that it won't be very sturdy, especially in the horns. So, I'm wondering, is there a good way to support it? I was thinking either cutting out more foam or a different material to go inside of it like in the next image, or make a wire skeleton. Would I have to try and get thicker foam instead?</p>
<p><a href="https://i.sstatic.net/Ldtz7.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Ldtz7.png" alt="Different flat shapes lodged inside of the model." /></a></p>
<p>To note, I also plan on making a sword prop that I have the same issue with, and I'm hoping that I'll be able to use the same method.</p>

CC BY-SA 4.0
2023-05-14T13:36:45.970Z
How are you planning to form your foam into shape and join it? That will affect how you can reinforce it. It also looks curved in 2 dimensions so I'm not sure how you'll achieve that
Chris H
CC BY-SA 4.0
2023-05-14T15:18:09.877Z
Have you ever made something similar, if so, could you please upload a photograph so that we can get an idea of your process.
Aaargh Zombies
CC BY-SA 4.0
2023-05-15T04:46:09.727Z
@ChrisH I've updated the image of the model to show the seams I've marked it with. I plan on joining them together based on the edges of the seams, and as you can see they're curved to follow the shape. I also plan on using a heat gun.

I also have to clarify that I'm more worried about it getting squished or dented and less about it being able to stand, as I'll be wearing it to a crowded area.
That1TVHead
CC BY-SA 4.0
2023-05-15T04:46:18.213Z
@AaarghZombies This is going to be my first time using EVA foam, so I don't have any photographs at the moment.
That1TVHead
CC BY-SA 4.0
2023-05-15T05:50:25.613Z
EVA softens nicely with heat, so that's good. But getting even heating through even a thin piece with a heat gun will be hard. Foam is a good insulator so the middle will warm slowly even if you heat both faces, and it won't be easy to avoid overheating. You might find it better to use an oven. You've also got to consider the joins. I wonder about laminating the 2mm foam with overlapping pieces on the inside. The inner layer doesn't have to be complete in all the fiddly bits. But this structure should probably be formed onto something to hold its shape while it cools
Chris H
<material-selection><costume-design><foam>
How would I go about making this 2mm EVA foam mask sturdier, and what should I use?
That1TVHead
# How would I go about making this 2mm EVA foam mask sturdier, and what should I use?

(Asked by: username_0 on 2023-05-14)

I made a plan for my mask to make a template pattern out of in a 3D modeling software, as seen below. The blue model is for scale.

[![![A 3D model of the mask I plan to make, with a picture of its planned pattern on the side](https://i.sstatic.net/NDM5h.jpg)](https://i.sstatic.net/NDM5h.jpg)

It's pretty big, and the only foam I have right now is 2mm thick, so I'm worried that it won't be very sturdy, especially in the horns. So, I'm wondering, is there a good way to support it? I was thinking either cutting out more foam or a different material to go inside of it like in the next image, or make a wire skeleton. Would I have to try and get thicker foam instead?

[![Different flat shapes lodged inside of the model.](https://i.sstatic.net/Ldtz7.png)](https://i.sstatic.net/Ldtz7.png)

To note, I also plan on making a sword prop that I have the same issue with, and I'm hoping that I'll be able to use the same method.

**Tags:** material-selection, costume-design, foam

> **Comments:**
> **username_1**: How are you planning to form your foam into shape and join it? That will affect how you can reinforce it. It also looks curved in 2 dimensions so I'm not sure how you'll achieve that  
> **username_2**: Have you ever made something similar, if so, could you please upload a photograph so that we can get an idea of your process.  
> **username_0**: @ChrisH I've updated the image of the model to show the seams I've marked it with. I plan on joining them together based on the edges of the seams, and as you can see they're curved to follow the shape. I also plan on using a heat gun.  I also have to clarify that I'm more worried about it getting squished or dented and less about it being able to stand, as I'll be wearing it to a crowded area.  
> **username_0**: @AaarghZombies This is going to be my first time using EVA foam, so I don't have any photographs at the moment.  
> **username_1**: EVA softens nicely with heat, so that's good. But getting even heating through even a thin piece with a heat gun will be hard. Foam is a good insulator so the middle will warm slowly even if you heat both faces, and it won't be easy to avoid overheating. You might find it better to use an oven. You've also got to consider the joins. I wonder about laminating the 2mm foam with overlapping pieces on the inside. The inner layer doesn't have to be complete in all the fiddly bits. But this structure should probably be formed onto something to hold its shape while it cools  

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## 2 answers

### Answer by username_2 on 2023-05-14. Score: 1

If your model is hollow but able to hold its own shape, you could use an expanding foam to fill it in order to make it solid.

Be extremely sparing as if you use too much it could burst out of the seams.

From context you seem to know your way around 3D modelling software, so you could simply make a crude version of your mask in the software and then ask someone at your nearest makerspace to help you to 3D print it, and then wrap the foam around the 3D print as a surface finish.

> **Comments:**
> **username_1**: I think a 3d-printed form is the way to go.  It doesn't have to be printed in one piece (you'd need a big printer).  You could use PLA (which is often the first choice of filament), even if heat-forming the foam over the top, as EVA softens quite a lot cooler than PLA.  
> **username_3**: @ChrisH This would make a good answer. I don't know much about 3d printing, but the contour lines from the 3d image above look like a great starting point for a basket armature.  

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### Answer by username_2 on 2024-04-21. Score: -1

This video contains a similar project to make horns from EVA foam, including methods to make it sturdier.

Their primary method is to use layering\laminating, and to ensure that the seams are solid. Overall, their process is optimized for strength.

<https://www.youtube.com/watch?v=2sCRCFy5Nbs>


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