Q: Can this pen be used with ink cartridges?
No, it can only be filled with bottled fountain pen ink.
Q: Does this pen use Japanese or Western nib sizing?
All TWSBI fountain pen nibs are made in Germany and use Western nib sizing standards.
Q: How do I clean out the ink that is stuck between the inner and outer caps of this pen?
The TWSBI pen's cap can be taken apart for cleaning. To clean your pen's cap, follow these steps:
1. Wrap a wide rubber band around the eraser end of a wooden pencil. It is best to try to cover the metal band around the pencil with the wrapped rubber band to prevent accidental scratching of your TWSBI cap.
2. Gently but firmly stick the eraser end of the pencil into the cap of your TWSBI pen, as far as the pencil will go.
3. Slowly pull the pencil away from the cap, with the goal of taking the inner cap with the pencil. You may need to repeat steps 2-3 a few times before the cap will pop out.
4. Rinse, soak, and dry the caps.
5. Remove the rubber band from the wooden pencil.
6. Gently but firmly push the inner cap back into the outer cap, using the eraser end of the wooden pencil. Be careful not to scratch the inner cap with any part of the wooden pencil.