In one sentence, describe what the following article is about:

When you are not using your pen, keep the cap on it. This will prevent your pen from drying out. If you leave your fountain pen lying down, the ink will dry up in the nib. If you are planning to store your pen for longer than about a week, you should remove the ink so that it doesn’t dry up. Remove the ink cartridge and clean out the nib. Allow the nib to dry fully before storing the pen. Then you can store this pen in a pen case. If you leave the ink in the pen, the ink’s acids will mix with oxygen and start oxidizing the nib. Pen cases are intended to allow pens to lie flat. This is not beneficial for pens that have ink in them, since it will allow the ink to settle in the nib. Use these pen cases if you have already removed the ink, or if the pen is brand-new and you haven’t installed an ink cartridge yet.

Summary:
Keep the cap on the pen. Store your pen pointing upwards in a cup or other pen holder. Remove ink for long-term storage. Store unfilled pens in a pen case.