So, I feel as if I’m getting somewhat obsessed with thermoplastics, but that’s okay by me!
What does it look like?
Kobracast is a thermoplastic version of Plaster of Paris bandages! No, seriously, check this out!
You might be able to notice that it has some fine wires going through it. Made up of a flexible knitted polyester fabric along with a thermoplastic, Kobracast is a lot like plaster of paris bandages, or simply plaster bandages. The difference with Kobracast is that you don’t get the flaky problem you do get with plaster. Furthermore, once you’ve heated it into place, you can keep doing this.
How does it take shape?
Much like with Worbla, you shape Kobracast with heat (Hence it being a thermoplastic). I used my trusty old heat gun for the job, however I’ve noticed a lot of people mention that this isn’t the most effective way, due to how sticky Kobracast seems to get. It’s said that Kobracast is best worked with boiling water (So bring yourself some tongs of some sort to lift it back out of the water!)
Much like Worbla, once the material has been heated, it becomes rather floppy and easy to shape. For my Oscar Kass mask, I blew up a balloon and by heating individual strips of plastics, applied them to the balloon directly. This is much in the same principle as doing a papier mache mask when you were a kid, but hey – If it’s effective, why knock it?
I mentioned how Kobracast is brilliant at structure. With all of the little holes in Kobracast, it’ll be quite a pain to paint. Instead, you’ll want to give your Kobracast creation another layer. From the application stage, I was able to make a perfect base for my mask. I’ve even worn the mask whilst wearing the robes, so I know this is the right size. Now that I’ve created the base, I just have to apply a layer of something else. I’ll use Worbla, as now that the base building stage is finished, Worbla will form quite nicely around the Kobracast.
Worbla is effective for a big area, as well as finer detail, however I found it wasn’t that good as a base structure. It was scratchy and solid with little elasticity once it had hardened. Kobracast however, seems to retain some of its elasticity once it’s hardened.
Kobracast, much like Worbla, is self adhesive. However, I have noticed that it gets really sticky on the fingers too in comparison to Worbla which really didn’t suffer that problem. That’s why people advise using hot water, pulling it out with some form of tongs or tweezers and then flattening it on a surface and brushing it down. I’ll be trying this in the future, as I didn’t get a perfectly smooth finish as a result of lapping pieces.
What detail can we do with Kobracast?
Kobracast can be sanded and it’s best used as a base. You might even want to consider using papier mache over the shape. If you have some way of making a mesh for a shape to begin with, then applying Kobracast over the mesh, that might be your best bets.
Kobracast is quite light, thus it’s perfect for making masks… Such as my Oscar Kass mask.
But I will have to show you my much improved mask… Another time!
What did you think of Kobracast? It’s somewhat cheaper than Worbla, but at the same time, you don’t really get a sheet as big as you do with Worbla. The flexibility makes it perfect for a base, which can then be covered with another material.
Granted, all of these plastics are not cheap overall. The roll in the first picture cost £14.00, but you get a 10cm x 280cm roll. Compared to Worbla, which for £30.50, you can get a 75cm x 100cm roll of, it’s hard to tell which is truly better value. I’d argue Kobracast is possible just that bit better value, but again, combined these two make a fantastic material to use for anything that you need to have sturdy.