Introduction: Creating Costume Armor With Wonderflex

This Instructable will guide you through the process of creating lightweight and durable armor for costuming using a material called Wonderflex.

While 90% of the armor in this tutorial will be comprised of Wonderflex, it's important to know that the best results come from using a myriad of materials. Wonderflex is a very capable material, but there are certain limitations to what you can accomplish with it. I'll also be using other materials to accent and enhance the appearance of the basic forms, and these will be called out and linked when appropriate.

In the images above, all armor parts except the helmet were made from a mixture of Wonderflex and Apoxie sculpt. If you're interested in the construction of the helmet, check out my other instructable detailing how to make helmets from videogames!

Step 1: What Is Wonderflex?

Wonderflex is a low-melt thermoplastic (activation temperature of 150°-170° F) with a woven fiber backing on one side. It sort of looks like very thick plastic duct tape. When heated, the material can flex and stretch into curves, including some basic compound curves as well. Due to the woven grid backing, Wonderflex can only do slight compound curves. You could make a radar-dish type shape but it would be very difficult to get it to make a tight dome.

Wonderflex is also self-adhesive, meaning if you heat up two sheets and press therm together, they will bond to one another as they cure. The more you heat the material up, the stronger this bond will become. I prefer to use a heat gun but you can also microwave smaller pieces if you prefer.

It is available in three thicknesses (.35, .45, and .69") and is shipped/sold in rolls. I buy mine from The Engineer Guy here in Atlanta, but there are plenty of distributorsonline who also sell it.

Even the thickest of their available products is still pretty thin for very good results, so you'll see in later steps I often double or triple layer the material to make curves smoother and cleaner.

Step 2: Recommended Tools

We'll skip the common stuff that most people will probably have laying about the house: sharpie markers, rulers, a well lit workspace. For working with Wonderflex specifically, I'd suggest the following:
  • Heat Gun
  • Trauma Scissors - these have a serrated edge which makes cutting even 3 layers of Wonderflex quite easy
  • Hand punch - Wonderflex doesn't take well to drill bits. For clean holes, a hand punch works best
  • Roller - for layering sheets together
  • Bucks & Forms - these can be anything that resembles the shape you're eventually trying to make. Wonderflex works best when stretched over or pushed into a mold or form. If you want to make rounded parts, glass jars or buckets work. More complex parts require more complex forms. More on that later.
  • Sanding sponges - for smoothing out texture on the material; more on this later as well.
  • Polyester filler & filler primer
  • Soldering iron or heat gun
  • Proper safety equipment - respirator, gloves and goggles for any sanding or painting, and the respirator isn't a bad idea when heating the material either!
For adding accent parts, I like to use a material called Apoxie Sculpt. Apoxie is a 2-part clay with a 45 minute work time that sets overnight and cures very hard with almost no shrinkage. It sands wonderfully as well, so even if your sculpts look rough you can always clean them up later. When working with Apoxie, it helps to have some clay tools to get the material into the desired shape, though this isn't 100% necessary. I've included a shot of a few of my sculpting tools for reference.

Step 3: Patterning Your Armor

A solid project always starts with solid blueprints. There are numerous ways to go about getting these, and with videogames being 3D modeled in the first place, a savvy builder can extract game files into 3D models which can be manipulated in a ton of programs.

A friend of mine was able to pull the game files from Skyrim into a series of 3D models I could rotate and view in Photoshop. I used these to take still screengrabs of the armor from head-on angles, then traced the patterns into flat shapes in Illustrator. This took some tweaking; the initial blueprints I made were often too small when wrapped around a curved shape, so they needed to be modified here and there.

I have a duct tape mannequin I made of my torso which makes projects like this much, much easier to work on. After printing out a set of armor templates, I'd loosely tape the parts together onto the form to approximate the shape of the armor. If pieces needed to be adjusted, I'd make alterations to the pattern, then print out a new piece.

Paper is a good analog for Wonderflex. While Wonderflex can take some gradual compound curves, it generally doesn't like to make any sort of "dome" type shape without darting or trimming it in order to do so. In the first photo, you can see how the seam line in the middle of the chest allows an outward compound curve, since the two facing edges are convex shapes. If you can build elements like these into your patterns, you'll save yourself a lot of frustration when trying to shape the Wonderflex later on.

Step 4: Make Thicker Sheets

With your patterns sorted, it's time to transfer them to your Wonderflex. Well, not just yet. The first step isn't necessarily tracing.

One layer of Wonderflex is actually quite thin, and will not hold its own shape very well under any sort of pressure or stress. Additionally, when shaping only one layer of Wonderflex, the material will tend to wrinkle along areas where it is stretched into a compound curve. My solution to this issue was to laminate several sheets together before shaping my parts.

For larger areas like the chest and back sections, I laminated three sheets of Wonderflex together by heating them with my heat gun, then rolling them together with the rolling tool seen in step 2. If you don't have one of these, a rolling pin or similar rounded item will work, but you might want to test it out first to make sure the heated Wonderflex doesn't stick to it. My roller has a silicone drum, so this wasn't an issue.

For other parts that aren't as wear-intensive such as the shoulder armor and thigh plates, I only used 2 laminated sheets to make the initial blank piece of material for the part. These were eventually strengthened later on though, after the base shape was finished. More on that later!

Recall that Wonderflex has 2 different surfaces: a smoother side, and a side with a woven texture to it. I found that the smoother side adheres better when heated up than the woven side, so avoid laminating two woven sides to one another if possible, as this will make a weaker bond.

Step 5: Basic Compound Curves and Cutting Out Parts

After you've laminated sheets together to make your blanks, its time to cut out the patterns.

I found that its much easier to cut the shape out of the piece AFTER it has been shaped to the proper curve. If you cut the piece first, then stretch it over a form to make it curved, you end up with something that will be distorted from the original intended pattern.

In pic 1 you can see a "blank" panel. This piece was made by taking a 2 layer laminated sheet of Wonderflex, then heating it over a buck. I used an old resin casting I had sitting around from a previous project for the shape, but pretty much any non-porous and heat resistant material will suffice. If you're after a large compound curve like this, look at large PVC pipe fittings - their gradual curves and high temperature resistance will make them excellent bucks for use with Wonderflex. In order to keep the Wonderflex from sticking to my resin buck, I covered the piece in tin ducting tape (pic 2)

For more simple shapes, like the curved pieces in pic 6, I heated laminated sheets of Wonderflex and draped them over the side of a bucket to cool.

A tip about getting the shape to cool faster: I kept a 5 gallon bucket filled with ice water next to my workbench. After heating a sheet, I would stretch it over the desired form, then submerge it into the water. Wonderflex takes about 5 minutes to cool fully in ambient air, but with this method I had a rigid sheet in seconds (pic 5).

Once you've got the shape you're after, take one of your paper patterns and trace it over the shape. I use small clips to make sure nothing moves around while tracing (pic 3). You may need to dart your pattern in order to get it to conform to the curve on the part in some cases.

After tracing your pattern out, just follow the lines! I have a pair of trauma scissors that I find work very well with Wonderflex (they have a slight serrated edge and are meant for cutting through many layers of cloth quickly - don't ask where I got them because I have no idea!) though an exacto knife works well also.

Step 6: Heat, Shape, Bend, Repeat - More Complex Curves and Shapes

There are some parts of this armor which won't conform to a readily available form or shape. The shoulder pauldrons and leg bracers are mostly even symmetrical curves, but pieces like the shin guards and breastplate will require a bit more ingenuity.

Hand shaping Wonderflex is possible, but the results will be a little lumpier than what can be done with a proper shaping buck. With parts like this, patience is key. Unlike the previous step, you'll want to trim out these pieces in flat form first, then pull them into shape gradually (pic 1)

Starting with the shin guards, I shaped the basic form over a mannequin leg (pic 2). While this gave me a pretty decent base form, the result had small wrinkles and the edges were quite wavy. In this instance, its best to shape a small part of the Wonderflex at a time. Concentrate on one area, heat it and shape it to your liking, then dunk it in the ice water bucket to cool off rapidly. Note the dart added at the bottom front section of this part, which was made in order to flare out the area around the boot. Add these as you move along when needed, then fill in the resulting gaps with more Wonderflex.

Pic 3 has more details added, but you can see the result of gradually shaping the material. There are still some wrinkles, but we'll tackle those and smooth them out later on in the process.

Step 7: Heat, Shape, Bend, Repeat Part 2 - Really Big Curves and Shapes

In pic 2 you can see my method for shaping the back and chest sections. Since these parts are far too large to fit into my ice water bucket, I started by heating the entire sheet on top of a damp towel. This was then carried over and draped on top of my duct tape torso form, then covered with a second towel soaked in ice water and left to cool.

This process was repeated several times - remove the damp towel, heat a specific area, form to shape, then re-apply the cold towel -  until the shape in pic 1 was achieved. It took several passes and stretching of corners and edges to get to this point, and we still have a lot of wrinkly areas to sort out, but it's getting closer.

In pic 3, you can see the front chest plate after shaping. I cut out small darts along the arm and neck areas in order to pull the shape in tighter along these edges and make the resulting curve more even. These were then covered with thin strips of Wonderflex to reinforce the seams (pic 6). If your armor needs to be smooth in these areas, you can fill in these darts from the back side to have a seamless finish.

Much like how the small bumps were massaged out of areas one small spot at a time in the previous step, you can do that again here to remove wrinkles in the surface of the larger armor parts. For this I filled a bathtub full of ice water (fun!) but you could let the Wonderflex air cool if you're not in a hurry.

After the parts are shaped to your liking, it's a good idea to put them back on the mannequin and make sure all your seams still line up (pics 7 & 8) Don't worry if things aren't perfectly smooth now, you're just trying to make it so no imperfections or surface variations are deeper than 1/8" or so - we can fill small dents and divots like that in later on in the process.

Step 8: Add Raised Details

Wonderflex works very well for large surfaces and broad shapes, but for more defined areas and crisp details, you'll need to switch to a different material.

My preferred go-to is a 2-part epoxy clay called "Apoxie Sculpt." All of the raised details on my armor, with the exception of the neck guards on the shoulder armor, were sculpted from Apoxie. 

In pic 3 you can see how rough my initial sculpt was. On the shin guards this had the added benefit of hiding the seam line between the two Wonderflex halves and making things look like one continuous piece. The nice thing about Apoxie sculpt is that you can sand it, much like bondo, after it has cured. This allows you to sculpt like a completely inept third grader (like me!) but still clean up your mess when things are cured!

Pics 4, 5 and 6 show the Apoxie as well as some details added with sintra (the black semicircle) and styrene (the smaller white semicircle.) For these parts, the Wonderflex was heated and adhered to the part directly, then the seam between the two parts was filled with superglue in order to make everything very rigid. I also added raised details around the perimeter of the armor with thin strips of Wonderflex, which were heated and pressed onto the base shape.

An important thing to note is that Apoxie Sculpt comes in many different colors. I accidentally purchased some of the "white" color, which seems to be a bit fluffier and harder to get defined edges out of than some of the other colors. In pics 7 and 8, I'm using the "natural" color, which is my preferred one to work with.

For rivets on your armor, my preferred go-to are furniture tacks. Places like ACE hardware sell them in various sizes and in hammered or smooth textures, and they work great. Pre-drill the holes, cut off the pointy end of the nail on the back, and super glue them into place (pic 10)

Step 9: Sanding and Smoothing

Grab your respirator and make sure to do this in a garage or outside; things are about to get dusty.

With the sculpting, shaping and fake rivets complete, it's time to start making things smooth in preparation for paint. The first step in this process is to grab some rough grit sandpaper and start smoothing out the rough Apoxie sculpt accents. Depending on how good you are at sculpting, this might be a very short or a very long process (pic 2)

Once all the Apoxie clay is smoothed out, get some high build filler primer (typically found at auto parts stores) and give all your parts about 3 even coats, allowing a few hours of dry time between coats (pics 3 & 4). This will build up a thick layer of primer on the surface which will start to fill in the fine texture of the Wonderflex. Pic 4 shows all the little bumps and ripples we'll be smoothing out soon.

For small imperfections and divots that the filler primer won't cover, I'll use spot putty as a filler (pic 14) this stuff is only meant for imperfections smaller than 1/16" thick. For this armor, you'll want it as thin as possible - very thick spot putty will crack when the armor flexes. If there are small parts to cover, you can apply it in spots like in pic 5. For the chest and back, which had a lot of small dents and the texture of the Wonderflex was very apparent, I did a skim coat over the entire surface before sanding back down. Using a sanding sponge for this technique will make sanding along the compound curves easier (pic 15)

If you have some areas with deeper imperfections or larger dents, you can use a polyester filler. My preferred filler for this is a product called Dolphin Glaze by UPol. This particular filler has a bit of flex and give to it, which will allow for the fact that Wonderflex isn't completely rigid. You can see this filler used in the back area along the sides, where there were still some small wrinkles from the initial shaping process (pic 9). The filler here is still at most 1/16" thick, but it helps smooth out the surface considerably.

After the filler, do a couple more coats of filler primer to see if you've missed anything. You may need to repeat this step a few times to make sure you've gotten all the divots and dents you want to fill in. If you're going to have some very heavily weathered armor though, you can leave it a bit rougher.

A tip about the edges of Wonderflex: sometimes while sanding or trimming, you'll get fuzzed edges from the woven fibers sticking out of the sides. A quick pass with a hot knife or soldering iron will melt these back into the rest of the material and clean the edges of your armor up considerably (pics 10, 11, 12)

Step 10: A Little Extra Damage

Since this is armor we're making here, it doesn't need to be perfectly smooth and clean unless you're fresh out of training. A little scuffing and scraping will make your parts look much more realistic.

Making gouges in Wonderflex is quite easy, just drag a hot knife or soldering iron across the surface and melt the gouge into your part. Make sure to wear a respirator when doing this, since I don't think vaporized Wonderflex is good for your lungs!

This technique may leave you with some blobs of melted material on either side of your cut mark. Just trim these away with an exacto knife before painting to clean up the edges.

Step 11: Base Coat Your Parts

In the world of videogame armor, there are all sorts of colors to choose from. The Skyrim armor I was making called for a warm brownish-silver color to simulate the "iron", but this technique here can be applied to gold, bronze, silver or any other metallic shade.

Layering is key. One color of paint will be just that: a single color, flat and boring. I start off by painting my armor with a base coat of medium silver, then build up coats of darker gray and bronze spray paint by lightly misting passes of spray paint over the surface until I get a nice mottled texture and color. The variations in the base coat will show through even once your piece is weathered and finished, so make sure to put in the time to do a good job! (pic 1 & 2)

I've found that Rustoleum hammered paints are extremely durable and even have a good amount of flex to them, which will prevent cracking in your paint job after you've worn your costume multiple times. You can see the paints I used on my armor in pic 4.

In order to make painting your armor easier, I suggest having or making a PVC painting rack (pic 5). This is shown with a different set of armor I was working on, but the concept is the same. In pic 3 you can see a bunch of masonite sticks which were hot glued to the backside of the armor pieces. These were clipped to the paint rack to make things easier to paint, instead of just laying them on the ground on a piece of cardboard. The hot glue won't bond to the Wonderflex if you use low-temp, but it is strong enough to hold the piece during paint until you need to snap off the paint stick.

Step 12: Weathering: Acrylic Paint

Weathering, much like the initial base coat, is a multi layered process. The first passes of this will be done with acrylic paints.

Starting out, mix up some dark browns and blacks (using brown or black straight from a tube has a tendency to look kind of grayed out and not as vibrant as mixed colors. Art school, woo!) and brush them into the cracks and seams in your armor. I like to keep a damp paper towel nearby, and wipe the excess paint away from the seams before it dries, leaving only the paint in the seams behind (pics 1, 2, 3).

If you'd like to see a version of this in action, I use a similar technique when weathering my handheld props. Here's a recap video of a process where I weathered a rifle from Mass Effect:

If you're only after dirty but otherwise well kept armor, you can skip a lot of the rest of this tutorial. A little bit of drybrushing along the edges of your parts to accent highlights and you'll have a well weathered piece of armor (pics 8 & 9 - these are vacuumformed pieces, but the painting technique is similar)

For the Skyrim armor, I needed some pretty heavy rust spots in certain areas. This armor is old and worn and very neglected. If you're after this sort of look, then read on!

To start, mix up some purple-red acrylic and stipple it onto areas where you'll want to apply rust later on (pics 4-7). Allow this to dry fully for a day before going to the next step.

Step 13: Weathering: Adding Rust

To make real rust on your armor, you'll need ferrous powder. I buy mine from a place called "The Compleat Sculptor" (yes, incorrect spelling is intentional!) Here's their list of fillers; the metal I use is the "Iron Powder - grey (325 Mesh)" (pic 2)

I have tried a couple different methods, but my current favorite is to take two paintbrushes, the powder, and a cup of water to apply it. First brush is saturated with regular water, then brushed over the area on your armor you want the rust to stick to. Take the second brush and scoop a small amount of powder onto it, then tap it lightly over the wet area to apply the powder. Wherever the piece isn't damp, the powder will fall away (pics 3-6).

Next up, get a disposable spray bottle (old Windex bottles work great here) and fill it with a mixture of hydrogen peroxide, vinegar, and salt. I mix these together in a 6:4:1 ratio by volume. Shake up the mixture in your spray bottle and set the nozzle to the widest mist setting, then spray lightly over the metal powder (pic 7).

Just to give you an idea of what to expect when you're spraying, initially the rust powder will make a sort of nasty yellow foam. This can be immediate, like right before your eyes, but sometimes it can take a few minutes as well. You can see this happening at about 2:58 in this video below (it goes by quick!)

This will fizzle down and settle into a nice rust texture pretty quickly (about an hour or so) but don't try to blast away this bubbling with your spray bottle! That's the chemical reaction taking place, and more accelerant will only remove the metal powder.

This kind of technique is a bit messy, and it can get away from you in a hurry if you add too much powder or accidentally blast all of the rust to an area on your piece where you don't want it. My advice is to start small, you can always add more after you've finished a coat, and a little powder will go a long way. You have spray carefully and make sure you get a spray bottle that doesn't jet out or you'll just blast away all the metal powder.

Things will look like pic 8 after spraying. You'll have some runoff which will be tinted with the color of the rust, but if that's a problem you can always buff it off with a scotchbrite pad later. Make sure to put some scrap cardboard under your parts to avoid destroying your work surface. Oh, it will also smell like hamster pee.

I let the rust cure for 24 hours before I do anything else to it, and initially it will look pretty grisly. Once the peroxide and vinegar are gone, a lot of salt is left behind, and it's not very pretty (pic 9)

A quick buff with a green scotchbrite pad will get rid of this (pic 10, 11, 12)

Step 14: Cleanup and Clearcoat

After buffing with the scotchbrite pad, you'll want to seal the rust with clear coat. I've tried several kinds but the best so far has been Krylon Satin clear acrylic. This will seal the rust, stopping the chemical reaction and preventing pieces from flaking off, and it will also darken the color somewhat. Don't worry if initially your rust turns purple when clear coated (pic 1) as the clear cures, your color will go back to its more orange hue (pic 2)

Pics 3, 4 and 5 show the progression from fresh rust to cleaned with a scotchbrite pad to final clear coat. I will sometimes follow up the clear coat with a little bit of purple or red paint on the rust spots to deepen the color a bit and keep it from being too cartoonishly orange. Pic 6 shows a contrast between darkening some of the rust with a purple wash of paint, and how it would look without any further topcoat at all.

Step 15: Paint It Black

This is a small step, but little details like this are often overlooked and they can make a good costume really great. Take flat black paint and coat the insides of all your armor. By now they're probably a crazy array of primer, paint, some rust blobs and who knows what else!

After all the clear is dried on the front, get some cheap flat black spray paint and paint all interior panels, or if you're nervous about over spray, bottled black acrylic will work as well.

NOTE: I got a little overzealous and did this before I had the armor strapping and rigging sorted. Its a better idea to wait until you've got all the snaps and screws in place before painting the inside of your armor.

Remember: if you glue onto a surface, you're gluing onto the material. If you glue onto paint, then that glue joint is only as strong as the bond between the paint and the part!

Step 16: Accessories

While this falls slightly outside the scope of "Wonderflex armor" it is something you can do to really enhance the look of your project! All of the rings and buckles on my armor were sculpted first in clay or cut from acrylic sheet, then cast in resin using metallic powders to get a shiny finish.

I detail the process of cold casting a little more extensively in my tutorial about how to make a videogame helmet, and you can read more about that here. The molds shown here are simple block pour molds made in tin cure silicone. For more information about block molds, check out this tutorial by Smooth-On.

Step 17: Strapping and Rigging

Snaps are perhaps the best thing I've ever found for rigging armor. Making armor snap onto straps allows you to put most of the straps in place, then affix the armor once you've got all of the bits in place. Much easier than trying to put a strap across your arm while it's glued to a big chunk of Wonderflex.

In pics 1 and 2 you can see how the shoulder armor connects to the shoulder strap with snaps embedded into the Wonderflex. In order to mount these in place, snaps were riveted to a small square of Wonderflex, which was then heated and adhered to the inside of the armor (pic 3) You can drill these holes in the Wonderflex if you like, but if you're using leather straps like the ones shown, you might have access to a punch (pic 9) which is a much easier way to make holes in the material.

In order to anchor these straps to the chest and back sections, I used a piece of hardware called "chicago screws" (they're also sometimes called "sex screws" but let's try to be adults about this, hmm?) (pic 8) these are screws which fit into a threaded sleeve that has a smooth back. Hardware like this makes a smooth connection on the inside of your armor so nothing sticks out like a bolt head or nut, and it also won't pinch the parts of armor screwed together and add to stress or strain (pics 4 - 7)

Chicago screws were also used on the insides of some armor parts like the scalloped armor plate on the left arm. Much like the snaps, a square of Wonderflex was heated over one half of the screw, then affixed to the inside of the armor. This makes a threaded insert on the armor itself, providing a convenient rigging and strapping point (pic 6)

Lastly, the sides of the armor had D-rings inserted - a piece of leather cord holds these closed. The D-rings are held to the armor in much the same way the snaps and chicago screws are: a loop of Wonderflex was made that the D-ring sits inside of, and this was then heated and affixed to the Wonderflex armor (pic 10).

It's very convenient that this stuff sticks to itself so well, but following it up with a little superglue also at the higher stress points where the armor is rigged up is a good precaution.

Step 18: Weather the Cloth, Too!

Remember, if your armor is nasty and crusty, tossing it over a crisp and clean costume will look very disjointed. Same goes for the straps!

The rather disgusting shirt in pic 1 started life as a custom made and quite handsome piece of linen and leather, sewn for me by my friend Cathy over at God Save the Queen Fashions (Cathy also made the pants, fur parts, and all the leather straps I riveted and snapped into place!)

This was weathered with coats of acrylic paint, mixed into various shades of green, brown, black and gray, applied liberally with a spray bottle and allowed to air dry for 48 hours. I also sprayed a small amount of bleach onto some spots for a bit of extra color.

The straps were treated to a similar amount of abuse, but were also scuffed up on my belt sander (equipped with 50 grit paper) to break the leather in a bit and distress the edges. With straps like these you have to be careful not to sand off the stitching though! You can more readily see the bleach spots on the leather here as well.

Step 19: Strut

Toss all your rusty armor over your stained clothes and go show it off! I wish I'd had time to do makeup appropriate to the rest of the grit in the costume, but I suppose that will have to happen next time.

A couple tips about storing your Wonderflex armor:
  • Do not store it in a position where it is being pressed down on or where there is anything flattening the shape out. It should keep its dimensions quite well on its own, but after enough time and pressure, the curved edges can distort.
  • Store it in a temperature controlled space. No attics, garages, or outdoor storage lockers. Heat will distort and damage those shapes you worked so hard on!
  • DO NOT LEAVE IT IN YOUR CAR, EVER. See "heat damage" above
Beyond that, enjoy your durable and (relatively!) inexpensive costume pieces!

If you'd like to learn more about making a helmet like the one shown in this tutorial, check out my other Instructable about making videogame helmets here.

For a write-up on the Axe shown in these shots, you can visit my website.

Thanks for reading, and good luck with your projects everyone!
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