Thermoplastics are all the rage for cosplayers in the convention circuit right now. You may have even heard of some these fun names: "Friendly Plastic", "Wonderflex", and "Worbla". But how do they work? What's the difference between Worbla and Wonderflex? And how do you even start using something like this?
Let's start with a brief overview of Wonderflex and how you might use it in your costume-making, using an example. Here is a very simple piece of armor I made out of Wonderflex, it is a back plate (quite literally a plate you wear on your back):
So how do you even begin to make something like this? Well, if you know how to use scissors, Sharpies, a hair dryer, a paintbrush, and a ruler, then you have all of the skills you need!
Wonderflex starts in a rolled-up sheet. When you heat it up you can bend it into shape, then cool it fast (dunk it under cold water) and it will harden and hold its shape. It also sticks to itself so you don't need to use a glue gun.
You can form structure of your armor piece by sandwiching a piece of craft foam between two pieces of Wonderflex (this is the same process for Worbla armor). Start by creating a pattern on butcher paper, then trace that pattern onto sheets of craft foam. Then trace each piece of foam onto Wonderflex (twice), leaving about 1/4" extra around the edge (like a "seam allowance" if this was fabric). Heat up both pieces of Wonderflex with your heat gun until they are all soft and floppy, then sandwich the craft foam between the Wonderflex. You can fold the excess edges over to the back side of the armor piece and press them down. Mold it into the curved shape you want by pressing it against your bold, then cool it quickly under cold water.
After you have built the piece, you can prime it and paint it. In the images above, you can see how I primed it with gesso and wood glue. Then I sprayed on a black primer and silver spray paint. Then I did a black wash and dry brush with black acrylic paint. Lastly, I added white line details for highlights to give it some pop and character.
Wonderflex is a little cheaper than Worbla, but in my opinion it is more difficult to work with (not as forgiving). With Worbla, you can use all of your scraps by melting them down and molding them like hot clay - you can't do that with Wonderflex. Worbla stretches and can be molded into bra cups, but Wonderflex can't stretch much because it has a fabric structure. Wonderflex is slightly stronger in a single or double-layer though because of that fabric structure. It's also smoother in texture than Worbla.
So these are my two recommendations. Use Wonderflex for:
- straps/loops for affixing D-rings to thermoplastic armor (recommend using 2 layers)
- large structures that require a lot of plastic which you want to do as cheaply as possible (like the armor piece above)
- thin, delicate items made with a single flexed sheet, like custom masks.
Stayed tuned for Worbla armor!
Where can you get Wonderflex? I bought mine at cosplaysupplies.com