Drawing a simple line can create fun bokeh too, and this ballpoint pen is the perfect tool for the job! :D

From Wiki:
A ballpoint pen is a writing instrument which dispenses a viscous ink from an internal reservoir through the rolling action of a metal ball at its point. This "ball point" may vary in diameter, and may be made of brass, steel, or tungsten carbide.

Originally conceived and developed as a cleaner and reliable alternative to quill and fountain pens, ballpoint pens are now the dominant writing instrument. Millions are manufactured and sold every day, worldwide, with low-cost and ubiquity assuring that there's always a ballpoint pen within reach.

This so-called "invention that changed the way we write" has also influenced the way art is made; some professional artists use ballpoints to create fine artwork. A popular disposable model has gained recognition for its industrial design as part of the permanent collection at New York's Museum of Modern Art. Designer ballpoints are also produced for the high-end market by pen manufacturers, and prized by collectors.