If the quality of the brush is not inferior, the reasons are:
1. Write big characters with a small pen.
2. The brush was not licked properly before writing. As the saying goes, "Printing the ink lightly, focusing on the pen" (Gao: in northern dialect, means "licking the pen"). Before writing, be sure to lick the brush well, that is, smooth the bristles.
3. I wrote too many words in one dip in ink, and there was no more ink in the pen tip, so I still had to write hard.
Licking the pen: After dipping it in ink, stroke the bristles of the pen on an inkstone or a special pen licker until it looks like a new pen you just bought - stuck with peach glue.