3D printing technology has been becoming more common and diverse for various researches and developments. Here we focus on 3D printing of soft-matter, especially introducing the latest progress of our 3D gel printing. We are developing various 3D gel printers, including bath-tub type, dispenser type and brick-building type. These printers can 3d-print finger tips for robotics, medical models for surgery, and fun foods for playing and nursing. The minimum and maximum dimensions of 3D printed objects depend on both the type and the materials used in printing. We will discuss what we need to study for leading Soft-matter 3D Innovation.