This is a proposal of Hanko, whose triangular handle is easy to adapt to your fingers.
Is the shape of the stamp easy to use really a cylinder? "FIT STAMP" was born from such trivial questions. The shape that gradually changes from a circle to a triangle makes it easy to pinch it between the thumb, index finger, and middle finger. You can feel a firm push, and the handle is triangular, so it does not roll when you lie down.