1. Method 1: Paper towel method: prepare several pieces of paper towels, stack them together, with a thickness of about 3 mm, and then lightly draw them with a pen core for about 10 second. The principle is that the reason why the refill is not used for a long time is that the pen oil freezes the pen beads, but the rough surface of the paper towel can effectively drive the pen beads to rotate, so that the oil can be used normally.
2. Method 2: Heating method: heat the pen tip with "hot water", "hair dryer" and "lighter", and then draw a few times on the paper.
3. Method 3: Replacement method: When one of the neutral refills is running out of ink, and the other refill can't write but has enough ink, the nib can be replaced to realize waste utilization.