View Full Version : Making Foamboard Keyblades - Tutorial

04-19-2008, 12:05 PM
You can make nice-looking Keyblades out of foamboard and Sculpey, which is what I used for Riku's Soul Eater sword here (http://www.cosplay.com/photo/1437613/). [Different angle here (http://www.cosplay.com/photo/1786486/)] So I thought I'd post a tutorial of how I made it.

I made a mini-Soul Eater for the progress photos, so please forgive the imperfections! The photos have explanations on them and are generally more detailed than the text here.

Keyblades made with this method:
Way to Dawn (http://www.cosplay.com/photo/2237434/) (made by TheWestWind)
Soul Eater (http://i128.photobucket.com/albums/p177/Akakioga/P1000911.jpg) (made by Ayame Uchiha)
Soul Eater (http://s738.photobucket.com/albums/xx29/spencercook8/?action=view&current=Photoon2010-09-15at1821.jpg&newest=1) (made by spencercook8)

If you make a keyblade using this tutorial, send me a PM or link to pictures in this thread if you want - I'd love to see what you created!

NOTE: This method doesn't provide the sturdiest results, and it does take a lot of time and fussy work. Nor is my way the only way to do things (especially since I still consider myself a newbie when it comes to this sort of thing ^-^) A lot of people have suggested good ways of adding more durability and support, so be sure to read their posts too!

large sheet of 0.5 cm thick foamboard
Sculpey of any color (I used almost 1.75 pounds) - paperclay and Fimo work, too
large sheet of normal paper
waxed paper
acrylic paint
hot glue
exacto knife (electric knives/hot wire cutters have been suggested also)
pencilLet us begin! ^-^

1. Make a template of the Keyblade on a big sheet of paper. Usually, it takes a few tries for me to get it right, so I don't like to draw on the foamboard right away.
2. Cut out the paper template, lay it on the foamboard, and trace around it.http://www.cosplay.com/photo/2106035/
3. Cut out the basic shape.Make sure you cut through all layers of the foamboard. Be careful not to pick it up until it's completely cut out or the weight of the board will bend the skinny parts of your prop, and that's not much fun to fix.
4. Draw the details onto the foamboard shape with a pencil.

5. Cover the foamboard with large sheets of waxed paper.Make sure there's lots of overlap on either side (you don't have to cut it to shape!) Tape the corners down to the table so it doesn't move. The waxed paper is so that you can move the Sculpey off your foam and into your oven without deforming its shape (as well as not staining your foamboard!)
6. Grab your Sculpey and, on top of the waxed paper, model the parts that you want to be 3D.Make sure you do a set for each side and try to keep them as thin as possible, or you'll risk bending/breaking your foamboard. And unless you have a REALLY big oven, you're going to have to split the Sculpey into several parts. Use a knife to cut the longer parts into smaller pieces; make nice, straight cuts that'll fit together nicely when you glue them later on. Then take the waxed paper off the foamboard (with the Sculpey pieces still on it). Put it on a baking sheet.
7. Follow the instructions on the package for baking the Sculpey.Watch the oven carefully to make sure that your waxed paper's not burning! When the Sculpey is cooled, peel off the waxed paper.
8. Using a hot glue-gun, carefully glue all the clay pieces to the foamboard.Make sure they're secure! Generally, I glue around all the edges and do one stripe in the middle of the piece, too. If there's parts of the clay that are slightly raised off the foamboard, just seal the hole with a line of hot glue.
9. Paint with acrylic paint and let dry.
I used acrylics easily found at a local art store - any opaque mixable acrylic will do just fine - and a #4 fine-bristled synthetic round brush. Once you're done painting, you can do a clear coat of sealer (clear acrylic, varnish, Mod Podge, floor polish, etc) over top you want. It's an optional step (I didn't do it on mine because I was lazy) but it'll help protect the paper layer and your colors.

04-19-2008, 12:44 PM
Nice tutorial. But I think that it will be alot faster and easier if you cut with an Electric Knife. They cut foam like butter and leave a smooth finished :)

04-19-2008, 01:28 PM
Thanks for the tip! I'll modify the tutorial. ^-^

06-05-2008, 08:24 AM
Kinda bumping an old thread because it's useful and hasn't been added to the Tutorial List yet.

Out of curosity, do you think that this would be possible with some sort of air-dry clay?

I don't know any particular brand off-hand, but it seems to me that if one could get through this without having to try and fit a keyblade-shaped piece of clay into an oven, it would be a major bonus.

06-05-2008, 09:55 AM
Thanks! ^-^

I'm pretty sure air-dry clay (like paperclay or something) would work just as well as oven-bake, as long as it's paintable and not too heavy. You make a good point!

06-05-2008, 09:59 AM
It may sound stupid (and perhaps due to misunderstanding the language) but I don't understand this step:
5. Cover the foamboard with sheets of waxed paper. Tape it down so it doesn't move. The waxed paper is so that you can move the Sculpey to your oven without deforming its shape.
I don't understand, do you put your foam togheter with the paper and sculptey in the oven?? (cause I always thought dat foam would catch fire!)

06-05-2008, 10:03 AM
Ooooh, sorry, I guess that wasn't very clear! ^^; Thanks for pointing that out!

What I did was tape the corners of the waxed paper to the table I was working on, with the keyblade foam underneath - not the foam itself. Just the paper and Sculpey go in the oven, not the foam. Sorry about that! Hope this explanation made more sense.

06-05-2008, 03:39 PM
But doesn't the paper get burned?? Or is wax paper totally different from usual paper (I'm sorry, some terms in English,I find difficult to understand)

06-05-2008, 03:46 PM
Yes it is different. Wax paper has a wax (or wax-like substance) in it that raises the temperature that it will burn at, as well as make it so things rarely stick to it. It is often used in baking (be it clay or cookies) as a liner for a sheet pan.

06-05-2008, 03:49 PM
Ow that^^ doesn't it look alot like aluminium??

06-05-2008, 03:53 PM
That would be aluminum foil.

http://en.wikipedia.org/wiki/Wax_paper is what ShadowWarrior mentions.

06-05-2008, 04:14 PM
OOW THAT o_O oh my god I feel so embarrased now >.< we have loads of that in our bakery oh my god! >.<
You see this is what happens during the examens ^^ Thank you for your patience!!

06-05-2008, 04:53 PM
It may sound stupid (and perhaps due to misunderstanding the language) but I don't understand this step:
5. Cover the foamboard with sheets of waxed paper. Tape it down so it doesn't move. The waxed paper is so that you can move the Sculpey to your oven without deforming its shape.
I don't understand, do you put your foam togheter with the paper and sculptey in the oven?? (cause I always thought dat foam would catch fire!)

I think she means that the wax paper is there so you can easily transfer the Scupley pieces to the oven. You need remove the waxpaper from the sword and Scupley pieces and put the sculpey pieces in the oven. Simple enough and makes sense to me.

If you were to put the Scupley pieces on the sword without the waxpaper, then it would be a hassle trying to scrape the pieces off, thus ruining its shape. With the waxpaper, simply pull it off the sword and take the pieces off. Waxpaper is a good non-stick surface.

06-06-2008, 03:59 AM
Simple enough and makes sense to me.

Yes indeed it is simple, now there are more sentences so I can get the point^^. English isn't my first language, although I can understand it pretty good, I sometimes have problems with some words or have grammatical problems. But it all makes sense to me now, and I want to thank all the above for being so patient and explainable (is that a word? >.<)

Thank you very much

06-15-2009, 10:37 AM
Oh man.. I'm so nervous to try this out xDD

06-15-2009, 11:17 AM
A few questions: By foamboard, you mean the pink or blue insulation stuff, right? You can hot glue stuff right onto the foamboard? Do you need to prep it or anything before you glue and/or paint?

06-15-2009, 11:48 AM
No, foamboard (also known as foamcore) is actually quite a bit different. It's a relatively thin layer of high-density foam sandwiched between two pieces of coated cardstock.

Picture here. (http://www.comade.com/Raw_Materials_-_Prison_Industries/Images/Products%20Page/foamcore_s.jpg)

Because it's basically just covered in heavy paper, you can hotglue it and paint it with acrylics, no prep necessary.

06-15-2009, 08:52 PM

That riku keyblade is too awesome for words, especially since it's made of foamboard and Sculpy.

06-15-2009, 10:09 PM
Thank you very much! ^-^

06-17-2009, 09:00 PM
How much Sculpey did you use on the handle. I'm really thikin of using this method for my keyblade. Awesome Soul Eater by the way.

06-17-2009, 09:45 PM
Hmmm, I can't remember exactly. I think the pieces on the handle were a bit thinner and flatter than the rest, though. I kind of cheated and wrapped it in black linen tape, cuz I broke it in the process xD Thanks for the compliment! ^///^

06-24-2009, 11:39 PM
I'm in the process of making a mini-Soul Eater and taking photos as I go. Hopefully they'll help to explain my random and crazy methods ^-^

I don't have any for the Sculpey molding part yet, but everything up to that point now has some captioned pics.

07-07-2009, 09:40 AM
So do you shape the 3-D parts with Sculpey on top of the foamboard, with a layer of waxpaper in between..? And the Sculpey goes on top of the wax paper and they both go in the oven? ..eh heh I'm having a bit of trouble with that part. ^^;

07-07-2009, 10:01 AM
Yes, pretty much exactly what you said! ^-^ The waxed paper and Sculpey go in the oven so the foamboard doesn't have to.
The paper makes it easy to take the clay off your board and makes sure none of your pieces will bend out of position. (Precise fit and shape is quite important). The paper won't burn.

It's raining over here today, so maybe my mum won't mind me turning on the oven to finish with the rest of the pictures. I'm terrible at explaining things in writing >_<

07-07-2009, 10:26 AM
Thanks, I totally understand now!
Don't worry, your a good explainer. :P

09-15-2009, 04:53 PM
Sorry for totally bumping this thread like months after, but I have to say this is an amazing tutorial. I used it to create Riku's second keyblade, Way to Dawn.
Here is a working pic (http://www.cosplay.com/photo/2227100/)

And here (http://www.cosplay.com/photo/2237434/) is the pretty much done. I should have sanded it most likely, but as usual I was pressed for time -_-. Also something to note is that the sculpey can get pretty heavy if you use enough of it. My key blade is kinda unbalanced, though the wing and the long blade part contribute to that. I also would definitely not be able to use it roughly as mine is pretty flimsy and it bends slightly if I hold it in the air sideways(Even reinforced with popsicle sticks). Probably a design flaw on my part, but yeah, haha

I wouldn't have had a single CLUE on how to make this if it wasn't for this awesome tutorial, so thank you for posting it sooooo much!

09-15-2009, 08:55 PM
I'm curious
What was your material cost?

09-15-2009, 08:56 PM
@TheWestWind: Oh, I don't mind at all, haha!

Wow, that looks great! Thanks for taking time to post photos! ^-^

The bending-while-holding-sideways thing is an unfortunate side effect of thin handles, long blades, and foamboard not being the sturdiest thing in the world, sadly (mine did the exact same thing; don't worry, it's not just yours) If I ever end up making another keyblade, I'm going to see if I can find some way to stop that from happening.

You're very welcome! I'm glad it was helpful!

@hayashiox: This is just a rough estimate. I think it was about $6 CAD for the foamboard, $8 CAD or so for the box of Sculpey, and probably around $7 CAD for the paint. I had all the other stuff (paintbrushes, exacto knives, etc) already.

09-16-2009, 10:31 PM
Is foamboard another name for craft-foam or foamies? I'm not quite sure what it is... o.o;

And how many layers of the foamboard was used?

09-17-2009, 09:55 AM
@Baku-Bug: Nope. Craft foam is a lot thinner, foamier, and more flexible. Foamboard (also known as foamcore) is a fairly thin layer of dense foam between two pieces of coated paper. Here's an example of what it looks like. (http://www.comade.com/Raw_Materials_-_Prison_Industries/Images/Products%20Page/foamcore_s.jpg)

I only used one layer, but you could easily use two or more for extra stability and dimension.

09-21-2009, 02:01 PM
Ugh, sorry for bumping and double posting >_< (Such bad forum etiquette on my part, tsk tsk)
Just wanted to mention that it finally got cold enough here to be able to turn on the oven, so the Sculpey steps now have photos as well ^-^

09-22-2009, 02:32 AM
I've been thinking about using this technique, but am concerned about durability. Has anyone tried putting a coat of fabric strips and glue (basicly a fabric mache coat) to strengthen the foam board before putting on the sculpty/air drying clay? Also, have you had experience with the clay shrinking at all while drying/baking?

09-22-2009, 08:19 AM
Oooh, that's a good idea, with the fabric strips. I must try that sometime! I'm sure it would help a lot with the durability.
I don't think I've ever had Sculpey shrink on me after being baked.

10-12-2009, 04:35 PM
When you say electric knife do you mean like a carving knife they use to carve meat and stuff??? LOL. sorry for the stupid question, I was just a bit confused :)

10-14-2009, 01:34 PM
Yup, pretty much! I don't actually use electric knives (it was a suggestion to put it in) but yeah, the ones that you use for food prep. ^-^

10-15-2009, 02:44 AM
Ahh okay! Thanks for clearing that up ^_^ lol.

10-15-2009, 08:32 AM
help!!! i love this thread and cut out Oathkeeper for my 1 year old (since i had to make it for him its alot smaller than normal)
the smaller parts around the hand are flemsy (i used foam board)
what can i do to reinforce it so it wont just snap!!!

thanks for any advice!!

10-15-2009, 10:43 AM
looks like people are saying use Gesso, anybody have luck with that?? i want to paint the keyblade tonight and finish my sons costume!

10-15-2009, 11:05 AM
What you should have done in this tutorial was inserted a few skinny dowels just to
let it have some support.

10-15-2009, 11:22 AM
urgggg too late now i cut it out already... its pretty small so the smaller parts on the design are extreamly week...

10-15-2009, 11:25 AM
Yeah, I know just giving you a heads up.
Well you could use paperclay. it's about $5-$7 dollars
and it dries pretty hard. i've used them to make handles and such.

10-15-2009, 11:30 AM
im going home at lunch to take ref. picture then that might help to show what im talking about

10-15-2009, 11:32 AM
Oh okay. Well that would help :]

10-15-2009, 03:14 PM
ref pictures of my process so far (excuse the others i just didnt want to put up 4 links when they are all in my gallary):



10-15-2009, 03:54 PM
Oh yeah! You're the one making the Brian suit. :] But anyways... Yikes! Oathkeeper and foamboard?! Is it already covered in something?

10-15-2009, 05:57 PM
no... i havent started it.. just the paper then layer of foam then paper! thats how it comes

11-07-2009, 05:56 AM
Sorry for commenting now after ages of you starting this board but I just thought it was a very nice tutorial.
I'm wondering what size of foamboard you used...?
Like, A3, A1 ect

I can get A3 for about 5 but then A1 is 20 which is quite out of my price range really.
I'm making Roxas' keyblade, Oathkeeper for my next convention [london mcm in may]

-I live in the UK by the way though you may have guessed that by my pricing of things in pounds

11-07-2009, 12:20 PM
no... i havent started it.. just the paper then layer of foam then paper! thats how it comes

Okay, I looked at your photos, it looks like you don't have enough room to put in dowels for support, and it's going to be really flimsy as is. I would suggest cutting out a matching one, and sandwiching it between coat hanger sized wire. That way you won't have too many hard edges for your son to hurt himself on, but it will have SOME structural stability. Good luck!

11-10-2009, 07:53 AM
@ThirteenthHour: I can't remember exactly the dimensions, but it was pretty big. Probably around B1 size. But wow, 20 for a tiny little sheet of A1 foamboard? That seems odd - over here you can get a nice big B1-sized sheet of foamboard for, like, $7.

Oh, and if you're making Oathkeeper, you may want to take a look at some of the suggestions other people have made in this thread for increasing stability ^-^

11-20-2009, 10:51 AM
How long is your actual Soul Eater?

11-20-2009, 10:58 AM
I made my Way to the dawn out of foam core and dowels and it's pretty sturdy ^_^!

11-20-2009, 06:00 PM
Art/Craft shops in the UK really suck. They have to import in all the stuff that I seem to want so it costs ridiculous amounts of money :[

Anyway, i've got some A1 foamboard and cut out my keyblade - going to use coat hanger wire for strengthening it :D

11-23-2009, 12:26 AM
@Manaih: It's 48 inches, so I guess that would be 4 feet? I'm 6'1", so I had to make it a pretty fair length to be proportional.

@hugginsseller: I took a peek at your WtD. Looks really nice!

@ThirteenthHour: Ah, okay, that makes sense. Coat hanger wire sounds like it could work pretty well for some extra support. Good luck! ^-^

11-23-2009, 10:49 AM
Shadow Warrior - Thanks a lot :]

12-18-2009, 10:08 PM
I know this thread has been going on for awhile...but what kind of paperclay did you use? or would it not matter?

I'm just slightly nervous, for I shall be making my first keyblades (yes, as in more than one...my friends are also taking part for our first real cosplay) so I just don't want to mess anything up and I want to make sure that I'll be able to make it okay and all that fun stuff.

01-02-2010, 08:32 AM
@justxsunshine: Aaaak! Sorry it took me so long to reply! D: I used Sculpey, which is oven-bake clay, but any kind of clay that's moldable/paintable/gluable and dries hard will work just fine ^-^

06-02-2010, 03:34 PM
When you say electric knife do you mean like a carving knife they use to carve meat and stuff??? LOL. sorry for the stupid question, I was just a bit confused :)

I believe what was actually meant was a "hot wire foam cutter" or etc.etc.foam knife, or one of the various names thereafter. It is a device in which a current is passed through a wire, which is used to cut the foam. This is typically used on polystyrenes, so i'm unsure of how it will interact with the craftboard covering the foam... because it's the heat of the wire that creates a smooth, melted edge to the foam being cut. It's likely you'll end up with brownish, burned paper... or even a small fire. Until someone tries it, i'd suggest having sand nearby to pour on it if it catches flame (never put out a fire involving electrical equipment with water). Here's a link on how to make one, since they can be a little harder to find as unmounted: Hot Wire Cutter (http://club.cycom.co.uk/hotwire/Hot_wire_cutter_for_polystyrene_foam.html)

I'm going to be trying this tutorial for a few of Aqua's keyblades, and will borrow a camera for pictures, especially during process, as i'll be experimenting with a few techniques i've come up with to possibly strengthen the overal stability and durability.

06-02-2010, 09:00 PM
Cool! I'm really looking forward to seeing what you come up with - I'm sure they'll turn out awesome ^-^ And thanks for the clarification on the hot wire cutter! Like I say, I've never actually used one so I put it in on a suggestion.

06-03-2010, 01:19 AM
Would Crayola Model Magic work as well as the Sculpey? I know Crayloa Model Magic is light so that would help with the breakage.

06-03-2010, 02:38 AM
How exactly would you insert wooden dowels for support? Prop making newbie here, sorry. >.>

06-03-2010, 06:44 AM
@Narnian: I imagine Model Magic would work fine as well. I'm not sure how sturdy it would be, but it definitely would be lighter! ^-^

@Rakoku: If it's thin enough, you should be able to stick it carefully through the foam itself, between the paper layers. You could also try sandwiching a thicker one between two separate sheets of foamboard although that might make a weird bump in the middle, not to mention a thicker prop in general.(And that's all right! Everyone's a newbie at some point. I'm still one myself ^-^)

06-04-2010, 01:32 AM
Ok, that's what I thought. Thanks! ^^

06-07-2010, 02:27 PM
*updated experience note*
Okay, just had some unfortunate experience that I thought I'd share with people. Crayola Model Magic is great in that you can smooth it with a bit of water so that you don't have those annoying cracks and creases when you have to use multiple additions over the drying process (and it does start to dry VERY fast)... if you aren't careful about where that water goes during the smoothing though... well let's just say that i've got to start over because of warped and beaded paper that got wet.

06-12-2010, 02:46 AM
Great suggestion! I didn't know that about Crayola Model Magic. Cool! How did it work? Sorry your paper warped.

06-13-2010, 12:00 PM
^^;; I feel nooby cuz I just draw on the foamboard and only use foamboard, scissors, acrylic paint, and occasionally a knife. Oh well, that's my 11 yr old on a budget way. XDD
I've made Soul Eater, Oblivion, and the Kingdom Key that way. (And it's not the most durable...My nana's demon dog destroyed the kingdom key.) And I'm hoping to do some this way. Thanks for putting this up and reading my crap! ^^;;

06-13-2010, 01:30 PM
Well, as long as it looks good the method used to make it doesn't matter so much, no? I bet yours look great - well, before the demon-dog incident, anyway ^-^

Ayame Uchiha
06-26-2010, 10:38 PM
Im using your method for a Soul Eater. Im so glad i found your tutorial! Its so simple, cheap, and yet is very durable! I cant wait to finish it. Im in the process of painting. Ill post a few pics when im done ^^

06-26-2010, 10:42 PM
Awesome! I'm glad it could help you out.
And yes, do post photos when you're done and I'll link them in the first post. I'm excited to see what you made! ^-^

Ayame Uchiha
06-27-2010, 11:02 PM
Heres the link to it on photobucket ;P I havent gotten them to cosplay.com yet, but i will soon ^^


06-28-2010, 10:11 AM
Excellent! I'll post that one for now ^-^

06-28-2010, 08:07 PM
Ah this is great. So going to use this. Thanks

06-28-2010, 10:58 PM
No problem! Good luck with your prop-making endeavors ^-^

08-27-2010, 10:20 AM
*gets shot for reviving old thread*

Sooo, potentially, this could be used for making any weapin, couldn't it? Or heck, a Shield even. This could potentially be a very versitile tutorial! Cool! I'll keep this on mind when I get called upon by my boyfriend or his friends to make props for their costumes. My boyfriend wants to cosplay as Bleach Shinigamis. D: The released forms. I had NO idea what I was going to do, but this seems like it would work, and be light-weight as well. I"ll tell him I found something!

*narrowly avoids having a tomato thrown at self*

08-27-2010, 09:36 PM
Theoretically, yes, it could be used to make a lot of things! Shields even, as long as they're pretty flat (since foamboard doesn't bend) It's not the sturdiest method in the world, but a lot of good suggestions have been made to make it more durable.

*eats tomatoes*

09-16-2010, 09:13 AM
this is my soul eater with this *very* helpful tutorial, thank you kerodohi!!!!!!


09-18-2010, 11:52 AM
You're most welcome; I'm glad it could be helpful! Thanks for the link ^-^

09-28-2010, 03:20 PM
this is awesome! Thanks for tutorial! :D

09-28-2010, 10:30 PM
Very helpful! Thanks! :3

09-29-2010, 06:37 AM
@CPQRyoko, @TheTurtleHermit: You're welcome! Glad to be of assistance ^-^

01-07-2012, 05:46 PM
ah i really like this. I'm using the *foam board with crayola magic* method for the oblivion keyblade.(of course, i decided to do this on a whim so.. well see how it works) I've cut it out, but because of the length of the keyblade and foam board, I've separated it into 2 pieces. i have the handle area and the blade area. I'm wondering how i could attach these 2 together with the most strength while still being able to hide the *glued?* area with the design found on the area where the 2 pieces connect, which is the end of the handle and start of the sword.

another thing.. how much sculpting skill do u need to do this? i suck at crafting but i do this all for cosplay :D

01-07-2012, 06:56 PM
For any of the blades that had to be made split in two, I've always sawed the ends off metal kitchen skewers or used thin wooden dowels. Just jammed those into the foam part on both pieces and shoved them together with some hot glue for added security. It's not the sturdiest, though - I used that method earlier on when I was still just making flat blades with no clay on top. I imagine it would be all right to model a solid piece of clay to go over top of that piece and hide the seam, but it would be more prone to breaking if the foamboard bent underneath it.

As for sculpting skill, I don't think you really need that much. Oblivion can be done fairly simply and still look good. Plus, I'm absolutely horrible at sculpting, so you should be just fine ^-^ As long as you have a good base to work from in terms of the outlines drawn on the foamboard, it's pretty straight-forward.

Also, if you don't mind, I'd love to see pictures when you get it done! It's always so cool to see what people have made ^-^

01-07-2012, 09:39 PM
Awesome tutorial! I'm gonna use this to make Void Gear, Vanitas' keyblade.

01-09-2012, 08:01 PM
oh thanks. haha wow my dad suggested the exact same thing