a) In case a pen tip gets scratched

• The pen tip has a very delicate structure in which a fine ball is assembled at the tip of a thin metal pipe. Therefore, even if you penetrate objects with a pen tip, draw a line with a metal ruler, or just drop the pen tip to the floor, the pen tip will be easily scratched.
• If the pen tip gets scratched and the ball does not rotate evenly, the writing line will be blurred. Also, when the ball does not turn, the ink will not come out.
• If you write with the pen at too much of an angle, parts that hold the ball wear on the paper surface, and ink may not come out.