1. Unscrew the pen.
2. Take out the ink absorber or used ink bag.
3. Insert the smaller end of the ink bag into the handle of the pen holder, and make sure to clip it into place.
Turn the pen back, flick it a few times or let it stand for a few minutes to write.
Extended data
Ink bag pen: ink bag pen does not need to absorb ink, and can be used by inserting a special ink bag.
Ink absorption principle: after the air in the pen bag is squeezed out, the air pressure in the pen bag is less than the external air pressure, and the external air pressure squeezes the pen water.
Maintenance of pen
When writing, pad some manuscript paper under the paper to enhance the elasticity of the pen tip and reduce friction. Don't write on hard objects such as metal to avoid damaging the nib. Avoid mixing different inks in daily use, so as not to precipitate and block pens. The pen should be cleaned once a month or so to keep the ink flowing. If carbon ink is used, wash it more. Pens should be cleaned and preserved if they are not used for a long time. And don't use too much force when writing.
References:
Baidu encyclopedia-pen