If you're just starting to cosplay then it can sometimes be hard to decide what kind of materials to use. Especially if this is your first time trying to craft a prop or armor. Some materials are expensive while others are inexpensive. I'm writing this to help you make a decision on worbla or foam. Check out my simple list of pro's and cons for EVA Foam, Craft Foam, and Worbla.
1) Let's start with the most expensive of the three, Worbla.
Worbla has some awesome benefits. For example you can heat it up and shape it to anything. You can place worbla over molds to take on shapes. You can also heat it up and roll it like you would play-doh to create accent pieces for armor. The best part about worbla? If you mess up you can heat it up and flatten it back to it's original shape. So, save every scrap piece because you can make use of them. It's also very durable, just don't leave it out in the sun/heat.
Sounds pretty awesome, but Worbla has a few cons. The biggest con is that it's expensive. If you're a cosplayer on a budget the prices makes it nearly impossible to use. Another downfall? You sometimes have to add fillers to it in order to achieve a smooth texture. And, then you need to sand it for evenness. Which leads to more spending...
I think this picture shows both benefit and downfall. My husband and myself used this body form to create a breastplate. Very easy. The downfall? We then added wood-filler to and he ended up sanding on it forever to even out the texture. Which leads to the next downfall of worbla, it's thin. We could have avoided using the wood-filler by using multiple layers of worbla. But that leads back to the cost of it.
2) EVA Foam
AKA Fatigue mats. The benefits of EVA foam are that it's not terribly expensive. It can be, but follow this link for the best price I've found so far. Another benefit is that you can choose different thickness for certain projects here. You can heat EVA up to shapes as well. Which means you don't have to do a ton to get that smooth even texture for painting. It's also pretty durable over time after it's been painted.
The cons of EVA? It's thick. Depending on what you're making it can be too thick. So, you may have to buy multiple sheets in varying thickness. To create some edges you may need power tools to achieve certain looks. You may also need to sand and saw the foam by hand. But, depending on your skill level that may not be an option yet.
3) Craft foam, the least expensive of the 3.
The biggest benefit of craft foam? You can buy it almost anywhere and it's really inexpensive. You can heat it and shape it just like EVA foam as well. You can use it easily for small accents or even some bigger projects. I have used craft foam for shoulder pads and knee pads pictured below (the breasplate is Worbla). You can see Rachel's Rory Mercury on the left and my Princess Pina co Lada on the right. The shoe details are also craft foam.
But, there are cons to craft foam. The biggest being it isn't very durable unless you coat it in plasti-dip or mod podge before painting it. As a beginner I made the mistake of using acrylic paints only for small armor details only have to pain scrap off during normal wear-and-tear.
I hope you enjoyed my list of benefits and cons to these 3 awesome products. You can search for many different types of tutorials using different materials. Hopefully this was helpful in your decision of choosing materials for your upcoming cosplays. Don't be afraid to experiment and learn. Now, got forth and be awesome.