Worbla is amazing and great for many things, but it’s very thin and flimsy when heated and shaped on its own. As such, when making armor and other pieces that need to have a smooth look, Worbla is often backed with foam. The sandwich method is the most commonly used and is mentioned in many tutorials. It can be sometimes replaced with the folding method, especially for pieces that do not need as much strength.
For everyone just starting out, we’ve broken down the steps here.
1) Have your pattern.
(Not sure how to make a pattern? We have a video tutorial for that, and you can also check out Kamui’s books!)
2) Trace it onto your foam and cut it out.
Not the most imaginative design, I know.3) Trace it out onto your Worbla, about ¼ an inch bigger all around. Cut it out twice, flipping the pattern for the second time. Remember that Worbla has a shiny side that has glue – you want to have those on the inside around the foam, so they need to mirror one another.
4) Heat your bottom piece thoroughly. It’s important to heat it completely so that it sticks to the foam evenly. If you’ve never heated Worbla before, it’s a good idea to practice this on a small test piece to get the feel for it. Worbla will change in colour and get a bit darker as it heats and activates. It will be ready when it’s completely floppy and tacky to the touch.
The darker piece has been heated and is ready to use.Once heated, press your foam securely into the Worbla, leaving that ¼ inch excess visible. Go slowly, and don’t be afraid to reheat if you’re working with a big piece.
5) Once your bottom piece of Worbla is attached, time to heat the top. Heat your second Worbla piece completely and press it over the foam and Worbla ‘bottom’, working from one side to another, making sure the Worbla is pressed firmly to the foam all over.
Now you can press the edges of Worbla together to seal everything together, then trim them. You can use tools to make this easier – wooden or metal tools for sculpting work well, but I find a plastic keycard from an old con hotel is a great multitool.
I forgot to document this on the first piece, so here’s an example from another.
All those edges get mushed together and the seam disappears.
Trim the excess, leaving a few millimeters around the outside edge. If you cut too close to the foam there’ll be nothing to hold the edges together and you’ll have to patch it.6) The reason you need to make sure everything is well and fully stuck is because now you can now heat your whole piece and shape it. If everything isn’t stuck down, you’ll get air bubbles. If you get air bubbles, follow this process to get rid of them.
Small pieces can be heated with your heat gun, but large pieces (such as armor) may be best to heat in the oven to heat evenly. Turn your oven to the lowest setting and lay the Worbla on a baking sheet on some baking paper. If the oven is preheated, you’ll only need a few minute – keep an eye on your Worbla!
7) Curious to the difference between straight Worbla and Worbla+foam? Look at the picture below. The right is a single piece of Worbla cut from the same pattern. This look works well for thin pieces that need an organic look – feathers and leaves for instance – but makes armor incredibly difficult.
If you need to create depth in a piece you can layer individual pieces of sandwiched Worbla ontop of one another, but that can consume a LOT of worbla. Another way to add depth is to layer your foam first, and then sandwich ontop of it.
You can see I decided to add the center pieces separately, to help emphasize their lines. Foam and Worbla layered like this can look ‘soft’.
Voila! You have now mastered the sandwich method of Worbla use.