Cheating the Chest Plate

by · July 2, 2015

If you’ve ever built armor for a cosplay, then you’ve likely had to build a chest plate of some form or another. Although there are multiple ways and materials to build a chest or breast plate from, some are harder and more costly than others. You could use EVA foam, but this can be very time consuming and has the potential to rip or break easily. You could use a thermo-morphic plastic like Worbla, but that becomes very costly, especially if you don’t know how to work with the material. Sintra is an option, but requires a lot of skill and patience to make the proper curves, especially if it’s a breast plate. Lucky for you, we’ve discovered a new, easier, cheaper, and less time-consuming way to make a chest or breast plate, thanks to the idea and methodology from our friends at Caliston Armory: Use a hanging mannequin.

Yes, I mean one of those plastic half people molds that stores use to display their clothing wares on. You can find them at display stores and online. We found ours at Advance Display, located locally in Salt Lake City. These cost about $10, and range in size and form. We recommend purchasing a white one, as it will make the patterning step a lot easier. Zabracus went with the “plus sized” one (it’s average sized, not plus). Although the pictures in this represent a female hanging mannequin, the same steps apply to a male hanging mannequin.

Step 1: Mannequin preparation. First you’ll need to cut off the neck, arms/shoulder bells, and the bottom of the thighs. We suggest using a circular band saw for this part. This allows you to hold the mannequin up to your body and figure out where you’ll want to draw your patterns. Next draw a horizontal line across the waist near the belly button, and then a Vertical line perpendicular to it, splitting the mannequin in half from the belly button up through the center of the clavicle.

Step 2:Pattern. Using a pencil to draw the structural design of your armor on one half of the mannequin. Next, you’ll want to trace that design onto tracing paper by taping the tracing paper to the center line you have drawn onto the mannequin. If you need to cut pleats/darts into the tracing pattern to go around the breasts, do so and tape them using either clear tape or masking tape. Next, cut that pattern out and flip it to the other side of the mannequin and trace that pattern onto the mannequin itself in pencil, on the anatomical side. Once it is traced to perfection, turn the mannequin over, and trace the lines with a black sharpie. This is done easiest over a light box or light source of some nature so that you can see your pencil lines through the other side (which is why we said to get a white mannequin!).

Step 3. Cutting. We suggest using a circular band saw for this part. It is possible to cut through the mannequin with a hot knife, but that will take ages, and the toxic fumes will likely give you cancer. When you cut on a band saw keep outside of the mannequin face down (this is why you trace the pattern to the inside) to prevent the saw from snapping your mannequin. Cut out all your parts carefully.

Step 3: Sanding and Fitting. The cutting will likely leave some messy and pointy edges, so you will need to sand those down. I recommend getting your hands on a dremel tool with a #80 flap-sanding bit, but it is possible to use just sand paper. Make sure to put the armor pieces up your body every now and again to make sure you have proper movement and that it fits properly. You’ll likely need to modify the shape here and there, which can be done using the tracing and cutting methods again.

Step 4: Details. As soon as you’ve made your armor fit around you perfectly, you can start adding details. If you are adhering other materials to the mannequin pieces, the adhesive we have discovered that works best so far is contact cement like Barge or DAP Weldwood. PVC glue does not hold, hot glue will not hold well, and super glue/gorilla glue hold ok. After you have the perfect design, you can of course start painting! You will most definitely want to prime it first, though. We suggest sanding down the paintable area a bit first, to help the primer catch better. You’ll also want to do a few coats. Zabracus used Plastidip as her primer, and it seems to have worked well thus far. After primer comes paint, then after paint comes a finish of some nature. (note: if you plan to rivet any strapping and need to drill holes through your mannequin, do that prior to Plastidipping).

Step 5: Admire. Your new chest/breast plate armor has now been created! Rig and fit it to your costume in whatever way best suits your purposes, and enjoy your sexy and anatomically “perfect” armor body.