Organ printing is a novel approach in tissue engineering that uses tissue spheroids as building blocks to create three-dimensional functional living tissues and organs. This method leverages the self-assembly and self-organization properties of tissue spheroids, which can fuse to form complex structures. Unlike traditional biodegradable scaffold-based approaches, organ printing does not rely on rigid scaffolds, instead using the natural biological processes of tissue fusion to guide the formation of vascularized tissues. This technique offers the potential for large-scale robotic biofabrication of living human organ constructs with built-in vascular systems, enhancing the field of tissue engineering. The paper discusses the limitations of traditional scaffold-based methods, such as vascularization challenges and the need for precise cell placement. It highlights the advantages of tissue spheroids, including their ability to self-assemble and their potential for scalable biofabrication. The concept of organ printing is presented as a promising alternative, inspired by developmental biology principles, which could lead to more efficient and biologically accurate tissue engineering solutions. The paper also explores the use of tissue spheroids in creating vascularized structures and the challenges in achieving rapid tissue maturation without scaffolds. Overall, organ printing represents a transformative approach in tissue engineering, combining biological principles with advanced manufacturing techniques to create functional human tissues and organs.Organ printing is a novel approach in tissue engineering that uses tissue spheroids as building blocks to create three-dimensional functional living tissues and organs. This method leverages the self-assembly and self-organization properties of tissue spheroids, which can fuse to form complex structures. Unlike traditional biodegradable scaffold-based approaches, organ printing does not rely on rigid scaffolds, instead using the natural biological processes of tissue fusion to guide the formation of vascularized tissues. This technique offers the potential for large-scale robotic biofabrication of living human organ constructs with built-in vascular systems, enhancing the field of tissue engineering. The paper discusses the limitations of traditional scaffold-based methods, such as vascularization challenges and the need for precise cell placement. It highlights the advantages of tissue spheroids, including their ability to self-assemble and their potential for scalable biofabrication. The concept of organ printing is presented as a promising alternative, inspired by developmental biology principles, which could lead to more efficient and biologically accurate tissue engineering solutions. The paper also explores the use of tissue spheroids in creating vascularized structures and the challenges in achieving rapid tissue maturation without scaffolds. Overall, organ printing represents a transformative approach in tissue engineering, combining biological principles with advanced manufacturing techniques to create functional human tissues and organs.