Plastic Defence is a documentary about illegal 3D printed firearms in Europe and the decentralised network behind them. These guns are robust, they don't blow up in your hands, and they're untraceable. What's more, they're being made in people's bedrooms. Popular Front got access to the network designing and building these downloadable rifles. It goes by the name "Deterrence Dispensed". Its members are determined to give untraceable DIY firearms to the world. We spent time with the founder of the movement—a man known as JStark.

• Documentary