Cause of ink leakage from ballpoint pen

b) In case from the back of the pen

b-3) In case exposed to high temperature

(Followers : Gel-like end plug moving to the pen tip side with consumption of ink)

When you store the pen in a car exposed to high temperature, such as the interior of the car (especially the dashboard), the air inside the ink and the follower may expand and push the ink or follower from the end of the pen.