Makes from the “graffiti edition” by studio Mifactori
‘O.Pen‘ is a simple but effective open design ballpoint pen with a cool feature: It supports all standard refills, not just one.
Status: Rough prototype/concept
Design info
Set stats: 3 prototypes, 20 makes, 0 products info
On parts & builds
- “It happened to most of us: Our favourite ball point pen is suddenly out of ink. We search for another ball point pen to swap the refill. Only to discover: the refills are different. The new one does not fit. Well if the O.pen is your favourite pen this won’t happen again.” The pen fits to all available refills:

- ↑ This pen can hold different kinds of refills. The inner tube has an insert thread to lock the refill in place with a set screw.
- The images show different prototypes testing the same idea. It works. ↑
- Need a cap? A short piece of silicone tube will do. (See image with the black caps)
Meta info
- O.pen is one out of six open design pens by studio Mifactori
- Please visit the original post by the designer to learn more about Penopen and how to make it and to see iterations of it. Initial post backup.pdf
- Pictures by Mifactori, CC-BY-4.0
- Disclaimer

Universal Parts
O.Pen
047.1 – Tube ⌀6mm, 18mm
046.2 – M3 knurled bolt 10mm
046.1 – M3 set screw 16mm
045.1 – Tube ⌀ ~8mm, ~130mm
NOTE: This set has more than one model. Not all parts in the list are required to assemble each version.






















