Pen Holder

A tool that makes a pen easier to hold. The hole for inserting the pen is a cylindrical shape of ○ x ○. Because the whole finger can grip the pen, it is easy to hold.

The surface of the grip has bumps to make it less slippery. Thanks to the parametric design, you can choose the cross-section shape from a circle, equilateral triangle, or square, and you can create a hole to match the writing instrument you use.