Foam Guide

[Fallen]

Contributors: RandomRanger , Fallen

Introduction
This is a tutorial targeted at beginners to help understand what EVA foam is, the different types of EVA foam available, how and where to buy EVA foam, and some basic tips/tricks/and tools for working with EVA foam.

Index
What is EVA foam?
What are my options when buying EVA foam?
The Grand Chart
Extra thick foam
Which foam should I buy?
Floor tiles vs Rolls visual
How much foam will I need?
Health and Safety
Tools and Materials
Tips/tools and misc. for working with foam

 

[RandomRanger]

What is EVA foam?
EVA (Ethylene-vinyl acetate) foam is a closed cell foam that is popular for making armor and props for cosplay and can be purchased in various densities and thicknesses.


Update: This write up has also been turned into a youtube video

 

[Fallen]

What are my options when buying EVA foam? (US-based)

Floor Tiles
A low cost, readily available source of EVA foam is floor mats or floor tiles. Floor tiles can be found at most hardware or sporting goods stores. The tiles may have a texture on one or both sides that may need to be sanded off if no texture is desired. Although floor tiles can be purchased in varying sizes and thicknesses, common dimensions are about 24” x 24” with a thickness around ⅜”-½”

Average Cost: $0.56 - $1.56 per sqft
Typically purchased in packs of 4 for about $9-$25

Locations: Harbor Freight, Home Depot, Lowe’s, Target, Walmart, Amazon, etc.

Rolls/Sheets
A little pricier than most floor tiles, EVA foam rolls can be purchased from foam suppliers online as well as cosplay shops. Rolls and sheets are the pricier option compared to floor tiles, but come with several benefits. Rolls and sheets are usually smooth on both sides and tend to be more consistent within brand in terms of density and thickness. If your templates have large pieces to cut out, using large rolls is great because it avoids the need for surface seams.

Average Cost: $0.80 - $2.50 per sqft
Locations: TNT Cosplay, Amazon, Foam Factory, SKS Props, Joann Fabric, etc.

 

[RandomRanger]

The Grand Chart (US based)

Brand	Foam Type	Color	Sheet Dim	Thickness	Price/Sq Ft	Source
Foam Factory	3lb density		4'x6'	3/8" (10mm)	$1.29 USD	link
Foam Factory	2lb PCLE		2'x4'	1/4" (6mm)	$1.50 USD	link
Foam Factory	2lb PCLE		2'x4'	1/2" (12mm)	$1.88 USD	link
TNT	EVA-38	White or Black	2’x5’	12mm (½”)	$1.80 USD	link
TNT	EVA-38	White or Black	2’x5’	10mm (⅜”)	$1.60 USD	link
TNT	EVA-38	White or Black	2’x5’	8mm (5/16”)	$1.40 USD	link
TNT	EVA-38	White or Black	2’x5’	6mm (¼”)	$1.20 USD	link
TNT	EVA-38	White or Black	2’x5’	4mm (5/32”)	$1.00 USD	link
TNT	EVA-38	White or Black	2’x5’	2mm (5/64”)	$0.80 USD	link
TNT	EVA-50	Black	2’x2’	8mm (5/16”)	$2.25 USD	link
TNT	EVA-50	Black	2’x2’	6mm (¼”)	$1.75 USD	link
TNT	EVA-60	Black	2’x2’	10mm (⅜”)	$2.50 USD	link
SKS*	HD-Foam	Light Gray	2’x5’	10mm	$1.90 USD	link
SKS*	HD-Foam	Light Gray	2’x5’	6mm	$1.40 USD	link
SKS*	HD-Foam	Light Gray	2’x5’	2mm	$1.00 USD	link
Harbor Freight	Floor Tile	Grey & textured	2’x2’	variable	$0.56 USD	link
What the Foam	Thermoplastic + EVA	Red	1’ x 112’ (x 6 sheets)	2mm	$0.64 USD	link
What the Foam	Thermoplastic + EVA	Black	1’ x 112’ (x 6 sheets)	4mm	$0.70 USD	link
What the Foam	Thermoplastic + EVA	Dark Gray	1’ x 112’ (x 6 sheets)	6mm	$0.74 USD	link
Yaya Han*	EVA	Black	2’ x 313’	2mm	$1.95	link
Yaya Han*	EVA	Black	2’ x 313’	5mm	$2.55	link
Yaya Han*	EVA	Black	2’ x 313’	10mm	$3.75	link

* These brands almost always have a sale and/or coupon code to use. Prices are without sales and/or coupons

 

[Fallen]

Extra thick foam
There is also extra thick foam which is useful for making props.
TNT Cosplay makes some: EVA-38 Extra Thick 24” x24”, Black
18mm - $2.49 sqft
24mm - $2.74 sqft
36mm - $4.00 sqft
48mm - $5.25 sqft

 

[RandomRanger]

Which foam should I buy?

Short answer: whatever fits your situation best.

Long answer: For a lot of people, the cost to build is the biggest factor. When this is the case, most people buy the floor tile foam as it offers the cheapest price per square foot and still has the potential to produce a high quality (Tier 3) product. Granted, hitting Tier 3 with floor tiles won’t be as easy as it would be with higher quality foam. For example, the Harbor Freight foam is known to dull blades significantly faster than high density foam and has a textured side that is often not accurate for Halo cosplay (though this isn’t an issue so long as one remembers not to use this side or sands the texture smooth). In the realm of high density foam, the first main difference is the foam now arrives in rolls or sheets. Rolls are a plus because if your templates have large pieces, you can cut them out all at once instead of having to glue multiple tiles together, which also helps save on scrap material. Additionally, given that rolls don’t have a textured side it’s easier to avoid messing up templates, and if you mess up tracing the template you can simply flip it over and use the other side. There doesn’t seem to be too much of a difference in quality between SKS, TNT, and similar foams, the main difference lies in the density of the foam being bought (high density is more expensive). Generally speaking, the higher density the foam is, the more ‘wood-like’ it becomes, making it easier to cut, shape, sand, and fill to perfection. Foam also becomes more rigid the higher the density is, so when making a prop (e.g. shotgun, battle rifle, etc.) it is preferable to use a high density foam so that the weapon has as little flex/’flop’ as possible.

In other words: if your main concern is the cost of the costume (i.e. hoping to spend less than $50 on foam), go with the floor tiles as they are the cheapest option and can produce high quality products at the expense of taking extra effort (though beginners may not fully capitalize on high density foam’s benefits anyways). If you’ve got more money to play with (e.g. have about $100-300 budgeted for foam) then higher density foam’s your best bet, simply go with the highest density within you budget.

 

[Fallen]

Floor Tiles vs Rolls Visual

This image is to show that you can get similar quality regardless of foam type used. The trade-off is increased effort.

 

[RandomRanger]

How much foam will I need?
This obviously varies, but to give a ballpark of foam quantity RandomRanger’s (6’1”) Reach Spartan consumed about 80 sq.ft. of foam. ODST’s often require less foam than Spartans. He4thbar’s (6’ 2”) ODST consumed about 55 sq.ft. Marines often require the least amount of foam. ZP180’s DFT Marine build consumed about 20 sq.ft., and SpiderMonkey60’s Halo 3 marine used about 2 packs of Harbor Freight foam (~$16 USD).

 

[Fallen]

Health and Safety
Note: we are not medical or safety experts, this information is tentative and from our own experience via trial and error. Read at your own discretion.

EVA foam is generally considered safe and doesn’t need safety gear to handle. Most EVA foams ship with a very strong chemical odor, and in large quantities (such as enough to make a costume) can have unwanted (and unknown side effects) if it is not given time to air out before use. For example, RandomRanger’s first order of foam consisted of ~70sq.ft. of foam and not knowing it would have a strong smell he left in his apartment unventilated for three days. During this time, there was a concerningly strong smell throughout the apartment, paired with a funny lightheaded feeling and a bloody nose on day 3. AIR OUT YOUR FOAM! Stick it in the garage, put a fan in a window, do whatever you have to do to air out the foam. It took RandomRanger’s first order of foam (70 sq.ft.) three days to air out, and he let his second order of foam (~250 sq.ft.) air out in a ventilated room for two weeks while he was on vacation.

 

[RandomRanger]

Tools and Materials

Here’s our recommended list of tools, some of which are optional and their uses depend on your crafting style.

Respirator with particulate and/or organic vapor filters EVA Foam Paper or Cardstock for templates Pens or Permanent Markers Push pins or something heavy Metal Ruler Low, med, and high grit sand paper Sealant (e.g. plastidip, flex seal)

9. Blades: utility, X-Acto knives, snap-off box cutters 10. Blade sharpener 11. Self-healing cutting mat 12. Hot glue + gun or contact cement 13. Heat gun 14. KwikSeal Adhesive Caulk 15. * Rotary tool with various bits 16. * Tape

* optional

 

[Fallen]

Tips/tools and misc. for working with foam

1. Wear a respirator with a particulate filter or a particulate mask when sanding foam. Even though EVA is generally considered safe, if you’re sanding the foam it can create a fine dust that is not good for your respiratory system.
2. Use Barge if you can. Hot glue is a common low cost, non-toxic choice of adhesive for bonding foam, however contact cement (e.g. Barge) is a stronger option that makes it easier to bond foam with minimal seams. Just note that contact cement needs good ventilation and/or an organic vapors respirator (~$30 USD).
3. Keep your blades sharp! The sharper your blade is, the cleaner the cut. The cleaner the cut, the better the seams. The better the seams, the better the armor! It is highly recommended to at least have a blade sharpener on hand to keep your blades keen (~$10 USD).
4. Use a metal straight edge/ruler. These can be useful for making angled/beveled cuts, making straight long cuts, or even simply marking cut lines on the foam. These are a good investment. We’d recommend getting one around 18in long.
5. Tracing templates. Templates can be traced onto foam using a ballpoint pen. However, if you find it hard to see the pen on your foam (e.g. black foam) you could switch to a white/silver permanent marker. Note however, that foam dries markers up fast. When using a pen, be careful not to tear into the foam.
6. Buy a heat gun. No, hair dryer DOESN’T COUNT. It simply does not reach a high enough temperature to heat the foam evenly. Heat guns are needed for shaping curves into the foam, sealing it for the painting step, and various other foam tricks like scoring.
7. Use something to keep templates down while tracing (e.g. push pins, something heavy). You don’t want them sliding around while you’re tracing them.
8. KwikSeal Adhesive Caulk. This is useful for filling gaps in seams as well as smoothing out cut/fuzzy edges. Other similar options include foam clay, or air drying clay.
9. Seal your foam. Use a heat gun to seal the outer foam layer, followed by applying a sealant coating (e.g. PlastiDip, LeakSeal, Mod Podge, Flexbond, etc.) before painting
10. Craft/exacto blades work great for cutting EVA along with snap off blades. We like to keep some of both on hand, and use what seems to work best for the type of cut we’re going for. RandomRanger got a bulk craft blade set for ~$10 USD and would replace the blade once he was able to hear it slicing through, and he still has half the blades from the kit. Fallen bought quality utility knives and a handful of X-acto knives with various blades and uses a blade sharpener and honing steel throughout the build process in order to keep her blades sharp.
11. Dremel/rotary tools can be useful for smoothing out cut edges, making unique cuts, cutting out circles, or gouging out trenches. Some recommended bits are low and high grit sanding drums (e.g. 60 and 600 grit) for cutting out circles and smoothing edges, cutting wheels and stone grinding wheels (for trenches). Most accessory packs have plenty of pieces to get you started.
12. For a smooth finish, EVA can be sanded like wood. Note: the higher the foam’s density the better it will sand.
13. Shoe goo can be used behind seams to make armor super tough, just be aware that shoe goo needs a well ventilated environment and maybe an organic vapor respirator (24hr cure time).
14. Have fun, and don’t rush it!

 

[he4thbar]

Amazing write up!!!! Good job to both of you and will be able to easily help newcomers asking for help or suggestions

 

[Rock Lobbster]

Word of advice, texture backed foam does not cut smooth with a laser cutter.

 

[Sean Anwalt]

Word of advice, texture backed foam does not cut smooth with a laser cutter.

Pics?

 

[PerniciousDuke]

Great write up! I love the tag team approach.

 

[Mtbdad]

Thank you for the write up. Can't wait to start my first project.

 

[Blanc0]

This is a really useful guide. Thank you. One question, do you know if Plastazote foam make for a suitable alternative to EVA?

 

[RandomRanger]

This is a really useful guide. Thank you. One question, do you know if Plastazote foam make for a suitable alternative to EVA?

Thanks!
Unfortuantely I'm not familiar with the plastazote foam. It is closed cell like EVA which is good, but that foam appears to be made with thermoplastic polyethylene foam whereas EVA which is short for Ethylene-vinyl acetate. I'm not sure what differences that'll add up to. The names appear similiar, so maybe that's just a specific form of EVA or another name for it, and it looks similar in the images, but I can't say one way or the other if it's a substitute.

 

[Fallen]

This is a really useful guide. Thank you. One question, do you know if Plastazote foam make for a suitable alternative to EVA?

Have never used plastazote, but I've commonly seen translucent plastazote sold under the name LED foam and mostly seen white plastazote used over LEDs as a diffuser.

I know at least TNT Cosplay and Lumin's Workshop sell plastazote for LEDs. But I can't speak to how good it would be as a subsitute for EVA. However, I did come across a few cosplay blogs in a quick search that used plastazote in making props (and not just for diffusing LEDs).

 

[coffeeee]

Thanks for making this, I just have one question. Whats a good thickness of foam to use for a set of ODST armor?