Whether it's for Cosplay, a LARP, sci-fi convention or Renaissance festival, creating your own wearable armour can add greatly to a costume. Metal armour can be difficult to work though, requiring skills that can take years to develop, along with the weight that you have to carry around with you during wear. Plastic armour, however, can give you the armoured look you want, from ancient Roman to futuristic Storm Trooper, all with a simple vacuum forming process that results in a lightweight wearable armour ready in minutes.
Create a model for the armour in the size and shape desired using a material that can withstand slight heat and pressure. Clay, wood or a high-density form are good materials to mould into the shape desired. Any details placed into the model will transfer to the armour through the vacuum forming process, so be as ornate as you wish.
Attach a vacuum cleaner with a hose to the suction hole of a vacuum forming machine large enough to hold your armour model. A vacuum forming machine uses the suction from an attached vacuum cleaner hose to draw a sheet of heated plastic over a model, recreating the shape of that model in the process. You can purchase one from arts supply or hobby shops, or build your own from the instructions listed in the Make Projects site in the resources section.
Place the model onto the centre of the former platform.
Attach the polystyrene sheet that you're using to make the armour onto the forming frame, using the clamps around the frame top, or stapling it in place around the plaster perimeter. Place the frame onto a baking tray and then into a preheated oven set to broil. Watch the plastic as it heats until it begins to ripple with waves. Wait a few more seconds for the waves to dissipate and become level again, then pull the frame from the oven while wearing an oven glove. The total heating time should be about 90 seconds.
Place the frame onto the vacuum former, over the model, pushing the plastic over the model until the frame is flat against the former platform. Turn on the vacuum cleaner to draw air from the former, pulling the plastic tightly over the model. The plastic will harden in place over the model, conforming to its shape.
Turn off the vacuum, then remove the frame from the former platform. Pull out the staples with a staple remover then pull the plastic from the frame. Cut excess plastic from the armour using a pair of sharp scissors or a hobby knife.
Attach straps to the inside of the armour after forming, for stringing the armour onto your body using an adhesive such as super glue. Test the adhesive on a piece of scrap plastic before use to make certain it won't melt the armour, as some adhesives contain solvents that can melt right through certain plastics when applied..