Additive processes, commonly known as additive manufacturing or 3D printing, are a family of manufacturing technologies in which a three-dimensional physical object is built up through the progressive addition of material, layer by layer, starting directly from a digital model (CAD). Unlike traditional subtractive processes (such as turning or milling), which "carve" the part by removing material from a solid starting block, the additive approach deposits, melts or cures matter—whether polymers, resins, metals or ceramics—only where it is strictly needed. This radical paradigm shift drastically reduces machining waste and offers unprecedented design freedom, enabling the creation of complex internal geometries, lightweight lattice structures and organic shapes that would be impossible to achieve with conventional techniques. Thanks to these characteristics, additive processes have evolved from simple rapid prototyping to the series production of high-performance end-use components, and today find wide application in cutting-edge sectors such as aerospace, automotive and biomedical.
