The video game and special effects industries lead the way in disruptive technologies for procedural 3D design, and we will explore how these techniques can be used in additive manufacturing to create customizable designs impossible in any other manufacturing process. Procedural design for additive potentially opens the door on the exciting prospect of mass customization and truly bespoke designs at scale. Several procedural techniques and concepts will be explored, each with their own capabilities. We will show how Blender can be used to create these procedural designs, but the principles explored can be used in many other CAD software packages.