General Craft Foam Tutorial

What is craft foam?

It has a lot of different names (like foamies for example) - but it is essentially a kind of open-cell foam.

It looks like this.

It comes in various size (the one I know of are sheets of 9"x12" (found at dollar store) or 12"x18" (found at Wal-Mart) or rolls of 36" x 60" (found at Jo'Anns)) and thickness (2mm, 3mm, 6mm, etc.).

 

Characteristics of craft foam

I love craft foam for a specific reason - I think it's a material that has a lot of advantages for costuming and its disadvantages can be easily overcome.

Advantages

  • Cheap
  • Lightweigth
  • Flexible
  • Can be heated to shape it (Thermoforming)
  • Non-Toxic (I point that out because more and more people out there are starting to use very toxic material for costuming - which I try to stay away from)

Disadvantages

  • Flimsy (doesn't hold it's shape - unless it's thermoformed)
  • Easy to tear
  • Rugged finish (not smooth since it's an open-cell foam
  • Doesn't breathe

 

How to overcome the disadvantages of craft foam

Flimsiness and easy to tear

These two can be taken care of by doing the same thing - and that's reinforcing your foam with hot glue.

When I build an armored suit in craft foam - you will never find a place where there is only 1 sheet thick of craft foam without anything to support it. What I usually do is that I sandwich a good amount of hot glue between 2 sheets of craft foam. Be careful when doing that - if you're using a hot glue gun you're most likely going to create "lines" of hot glue and then you stick the second sheet on top of the first. Depending on the temperature of the hot glue (if it's very hot it can warp the craft foam), the lines of hot glue could be visible on either side of the armor part. On the inside, it's not so bad, but if those lines are visible on the outside, it may ruin the smooth look you needed. By the way - those lines will not be "that" visible, but they will show... and if you're looking for the perfect smooth finish, then watch out for the temperature of your glue when applying it. You could go with a Low Temp gun (using Low Temp glue) or just make sure you spread your glue all over, not just in "lines".

But then - once you've got that hot glue sandwiched between the two sheet of craft foam, it makes the foam very very durable. If you've applied enough hot glue, it won't tear and could support a lot of weight or tension.

 

I like using hotglue to reinforce my craft foam armor because I feel it's stronger than other method - however, another method is using fabric to do the same thing. This method is part of Entropy House craft foam armor tutorial. She adds a fabric backing to her foam armor and she glues it on with regular elmer's glue. I would recommend using a fabric that doesn't strech much... you want it to strech a little bit, so the craft foam doesn't lose it's flexibility completely, but not too much, since it won't bring much support.

 

The same process can be used to make foam hold a certain shape. If - while the hot glue is cooling - you hold your foam piece in a certain shape, then once the glue has cooled down, the foam will retain the shape you held it in.

For example if you're making a bracer and you want the foam to hold the curve of your arm and wrist... then it would simply be a matter of cutting the parts of foam you need (2 of them) and glueing them together while you're holding the curve on your arm (careful though - hot glue is ... well, euh... hot) or holding the foam in a curve in your hands. Once the glue will have cooled, the foam piece will hold that shape. 

However, remember that foam can only bend "correctly" one way - so even by using the method explained here you won't be able to make foam hold complex shape unless you've cut the foam accordingly (please see my armor patterning tutorial for advise on how to do this)

 

Rugged finish

The process of smoothing out craft foam is explained at lengths in my craft foam finish tutorial.

 

Not a breathable material

Well, this one is a bit more difficult to solve than the other disadvantage. What I mean with "not breathable" is that craft foam will not let heat dissipate or sweat go through. So if you're completely clad in craft foam, you'll find that wearing such an armored suit is going to get real hot real fast. Please be very careful when wearing a full suit of craft foam armor (the same advise would applie to a full suit of regular armor) - stay hydrated as you'll be loosing a lot of water through sweating and try to stay cool anyway you can. Standing under a cool air vent is one way of staying cool, being outside if it's cool (beware of the sun though :)), etc.

However, there is something you can do to make the wearing of your craft foam armor a bit more confortable.

  • Make padding with natural fabrics - this will help soak up the sweat so the armor won't feel soggy all the time.
  • Include air vents when you can - to help circulate air in your armored suit
  • Include fans - if you know a bit about electronics, include fans inside the armor, so you get the air circulating

 

Conclusion

I think foam (not just craft foam) is one of the best costuming material out there - if you know how to use it. It gives wonderful results and is ligthweight (which is very important if you're planning to wear that costume during a whole convention day). It's also very cheap when compared to other material - helping you keeping a costume on a budget.

If you want to know what can be done with craft foam - have a look at my various galleries. If you see a costume that includes armored components, it's most likely made out of craft foam :)