Fused filament fabrication (FFF, widely known by the commercial term FDM) is the most widespread additive manufacturing technology in both hobbyist and professional settings. The process is based on the extrusion of a thermoplastic filament — heated to its melting point inside a nozzle — which is deposited layer by layer onto a build platform, solidifying in air to form the final object.
Its popularity stems from a combination of operational simplicity, low cost of both machines and materials, and a mature ecosystem that ranges from classic PLA and ABS to engineering polymers such as PETG, ASA, Nylon and composites loaded with carbon fibre or metal. Machines span a range from compact consumer desktops to industrial systems with large build volumes and advanced temperature control.
The main limitation of the technology lies in the visibility of layer lines and the need for support structures for overhanging geometries — factors that often require a post-processing stage for aesthetic applications.
