Advancements in additive manufacturing materials and procedures have helped in the production of complex architectures. Improvements in the printing speed and precision have made additive manufacturing a preferred method for rapid prototyping and scalable production. The movement toward environmentally friendly manufacturing techniques and materials has catalyzed the development of biodegradable and recyclable 3D printing filaments. This chapter describes the fundamental principles of ecomaterials design for 3D printing and the possible applications of 4D printing. It will discuss recent advancements in the aerospace and automotive sectors and examine concerns about microplastics in the environment and their impact on health. It will highlight materials used in 3D printing filament blends, including polyhydroxyalkanoate and polycaprolactone, and their role in minimizing the environmental impacts of additive manufacturing. The chapter will conclude with a look at the future direction of ecomaterials for 3D printing, focusing on the trends in their development and progress toward closed-loop material cycles and scalability. It will also highlight the advances in construction, healthcare, and engineering. The methods detailed in this chapter introduce sustainable materials and techniques in additive manufacturing. Further comprehensive information can be found in the references attributed to this chapter.