For prolonged durations of time For long periods of time, the 3D pen isn't suitable for long periods of time. It utilizes melting plastic to create your drawing. It can be heated over time, which is why it's important to allow it to cool. The most effective 3D pens need only a short time to cool so that you can resume drawing as quickly as is possible. 3D pen technology is operated by heat, and it functions flawlessly only after heating the plastic correctly so that you can draw or doodle. When you are choosing the right 3D pen to improve your creativity, cooling is essential.