Additive manufacturing has advanced rapidly since its origins in the 1980s. While some processes are now commercially viable, others remain experimental. A key ambition has been to combine multiple materials in a single part, enabling novel properties and overcoming traditional limitations of fabrication and assembly. Multi-material additive manufacturing offers a potential step change across industries, though scaling from lab to industry remains a challenge. This work explores the enabling technologies and science behind metal multi-material additive manufacturing and proposes how the research community can advance these innovations for meaningful industrial impact.</p
