This study investigates the design, processing, 3D/4D printing, and characterization of novel PETG–PBAT blends. The blends were prepared using melt mixing with three weight percentages of PBAT (10%, 20%, and 30%). Granules were obtained for 3D printing using a granule-based material extrusion method with a pneumatic system to control the melt flow. The results showed that the PETG–PBAT blends were immiscible but had proper compatibility, leading to excellent mechanical properties and printability. Tensile strength and elongation increased and decreased, respectively, with increasing PBAT content. The PBAT10% blend had a tensile strength of 36 MPa and an elongation of 51%, which is superior to other 3D printing materials. The PBAT30% sample, despite low printability, showed over 100% elongation and good toughness. Shape memory performance improved with increasing PBAT due to reduced transition temperature and enhanced elasticity. The study highlights the potential of these blends for 3D and 4D printing applications.This study investigates the design, processing, 3D/4D printing, and characterization of novel PETG–PBAT blends. The blends were prepared using melt mixing with three weight percentages of PBAT (10%, 20%, and 30%). Granules were obtained for 3D printing using a granule-based material extrusion method with a pneumatic system to control the melt flow. The results showed that the PETG–PBAT blends were immiscible but had proper compatibility, leading to excellent mechanical properties and printability. Tensile strength and elongation increased and decreased, respectively, with increasing PBAT content. The PBAT10% blend had a tensile strength of 36 MPa and an elongation of 51%, which is superior to other 3D printing materials. The PBAT30% sample, despite low printability, showed over 100% elongation and good toughness. Shape memory performance improved with increasing PBAT due to reduced transition temperature and enhanced elasticity. The study highlights the potential of these blends for 3D and 4D printing applications.