The Thermoplastic Theorie
Published on Dec 7, 2010
Today I want to show you something new. Last time I experimented a bit and became acquainted with some nice, new thermoplastic materials: Fossshape, Kobracast and Polystyrol. You also saw my Wonderflex and Friendly Plastic projects, and I guess it’s a good time to compare all materials with each other. So… let’s start!
Here you see all of them. I used a hot air blower for my work and despite all of them being thermoplatic they have different attributes and are suitable for different functions.
The first material I want to show you is Wonderflex.
If you know my costumes you also know Wonderflex and maybe you already worked with it. As you can see it has two different surfaces. I prepare the left for a part you can see later, because you need less work (I use Gesso for this step) to get it smooth. Now you can order a smoother Wonderflex from Dazian and mycostumes and it needs a bit less work then the old version. This material is also a bit elastic, but you need a lot of force to extend it, so it’s only possible with smaller parts. You can reheat it as often you want and you need no glue to connect different Wonderflex parts with each other. So, it’s a really nice material for huge armor and also for smaller parts. Here are some facts:
Thickness: ca. 1mm
Elasticity: 30%
Need of heat: ca. 10 seconds
Time to work with: 1 or 2 minutes
You’ll find a lot of tutorials and progress pictures at my tutorial page or in my last projects of my blog. This is an expample what you can do with Wonderflex:
 The next material I want to introduce is Friendy Plastic.
You can buy it in form of pallets, sheets or strips. It’s very hard and white when it’s cold and you can activate it with heat. I use the pallet form, put a bit of it into a metallic ladle and heat it with my hot air blower at the backside. When it’s transparent it’s hot enough and you can work with it. It’s better to use gloves, because it’s very hot and gluey. So put some water on your fingers and then sculpture every shape you need. But take care: If you need a big or thick form, it’s difficult to reheat it and work a second time with it. It becomes transparent at the outside at first and then the heat moves into the rest of the shape. Unfortunately the other layer will deform and collapse and the inner part is still hard. So, be sure what you do and know that you’ll mostly have no second chance without to redo it completely a second time!
Friendly Plastic is a really great material if you also work with Wonderflex. You can combine it, add plastic details, correct bad, bumpy parts of your armor or sculpt little parts.
Shop: You can order it from mycostumes, cosplaysupplies, eBay and many other shops
Thickness: –
Elasticity: Like a chewing gum!
Need of heat: ca. 20 seconds for pallets
Time to work with: 1 or 2 minutes
 Now we’re coming to Kobracast.
Maybe you know it from medical bandages, but it’s a very special material which will be used for threedimensional work for movies, theaters etc.. It’s quite similar to Wonderflex, but also completely different. At first, it’s better to heat it with hot water and to use gloves. It sticks a lot on your fingers, despite not as much as Wonderflex on other Kobracast parts. The main difference is that is very lighweight and it’s very elastic. So, if you’ve always worked with Wonderflex, you’ll get a complete new application with Kobracast. It’s a perfect material to create masks and organic forms and you can also use it for armor. But just as with wonderflex you have to use a coat at the parts which will be seen later. Kobracast is also very new for me, so I cannot show you so much. But you find some really nice samples here.
Shop: You can order it from mycostumes or from
Thickness: ca. 1mm
Elasticity: ca 80%
Need of heat: ca. 3 seconds
Time to work with: 30 seconds
This way my first time I worked with:
Now it’s Polystyrols turn:
You can find Polystyrol in home depots or hobby stores (… at least in Germany) in different thickness and colors. The sheets are very hard and solid and they aren’t elastic, don’t glue at each other or are very well to form. But if you need a clean, smooth surface or just a solid and stable base, this material would be the right choice. It’s works also very well for easy armor or weapon parts or if you just have to build something… square or technical. However it’s a bit difficult to work with. You need a hot of heat for a very short time period to work with and you have to take care that you don’t use too much heat.
Thickness: ca. 0.3 – 5 mm
Elasticity: –
Need of heat: ca. 15 seconds
Time to work with: 5 seconds
And the last one is Fossshape.
Unfortunately I’m still not able to tell you so much about this material, because you need a steamer to work with it and I still have to buy one. It’s a bit like a fleece made out of thermoplastic thread. I already saw a lot of very awesome things made out of Fossshape, so I wanted to inspire you a bit, even it’s not my own work. So, please take a look:
You can order Fossshape from DazianFabrics. And I hope’ll be able to show you my own results soon! :)
So, I hope you liked my little material introduction a bit and find some inspiration and help for your own project!
So, and as you saw in the pictures above I’m working on a new armor part, my left Demon Hunter pauldron. Here is a little making of for you:
After my little presentation you see that I used a lof of the thermoplatic materials above: Kobracast for the basic form, Friendly Plastic for the teeth, Polystyrol for the white smooth sheets and Wonderflex for the details. Now I create a clean, nice surface with some help to paper mache and try to sculpture a real looking texture for my horns. You can find more informations on my facebook progress page if you’re interested. And because there are soooo many guys who are asking me about my paper mache technique I also made a new video tutorial. Don’t forget to acitvate the subtitles! :)
And now… I hope I could help and inspire you a bit!
Be busy and keep creative. Bye bye and see you guys later! :)

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  1. Hallo Kamui!
    Deine Kostüme sind großartig und auch vielen Dank für deine Anleitungen! Ich habe gesehen, dass du auch mit Worbla’s gearbeitet hast und da ich mich auch demnächst an diesen thermoplastischen Sachen versuchen wollte, habe ich eine Frage: Welches der Materialien (insbesondere meine ich hier Wonderflex, Kobracast und Worbla’s) wird am härstesten bzw. am wenigsten flexibel? Und bricht es dann schnell?
    Danke im Voraus! Es ist wirklich super, dass du dir die Zeit nimmst, anderen auf die Sprünge zu helfen.

  2. Thank you for a wonderful and inspiring blog! I came here following a search for how to carve expandable foam, and had no idea I would stumble upon such a beautiful place. you are very talented! It is wonderful to see someone who takes their time and loves the art they create. I look forward to seeing more.

  3. u are a god!

  4. Thank you so much for your wonderful comments, guys! I just love you! :)

    Hm… man kann es sicher auch selbst herstellen, aber frag mich nicht wie. Google hilft da sicher weiter! :)

    Sorry, I have no idea how many I used. Maybe 2 hand full of this stuff? And it’s better to paint it with a base color at first, but then you won’t have any problems. :)

  5. Hi Kamui !

    I love what you do, you give me lots of great ideas !

    How many “Friendly Plastic” did you use to make tooth for your skull pauldron ? And can you then easily paint Friendly Plastic ?

    Thanks you in advance for your answers !

  6. Gibt es denn keine Alternative das ”Magische Papmache’ aus der Tüte selbst herzustellen?
    Es ist ja recht teuer.. und ich habe mal im Kunstunterricht gesehen dass meine Lehrerin einen ausrangierten Mixer benutzte oO

    Danke für deine tollen Videos! Die geben deinen Tutorials nochmal mehr Einsicht in deine Arbeit

  7. I’ve been one of those people that had no clue about paper mache, yet it’s such an inexpensive and easy to use method. I shall no longer fear to use it!

  8. Throughly enjoyed…..informative and well done. Anxiously await for when we can see more about your experiences with FOSSHAPE. And please let any of your followers and admirers know that if they want a couple of free swatches of either FOSSHAPE and or WONDERFLEX to contact me and Thermoman would be glad to accomodate

  9. Thanks for this post! Maybe now I can be brave enough to try make some armour from something other than cardboard :’D

  10. Great post! I’ve worked with some of these materials before, but it’s nice to see them compared with each other. The video was also really helpful. Thanks!


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