Ink of ballpoint pens
■ Oily ink
In JIS, it is possible to write out well even after 15 months from the date of manufacture. The product of the Tombow is guaranteed 24 months. Because there is a lot sign in the wick, it becomes important to confirm it at the time of the purchase.
It is said that the oil can usually be written normally for five years though the longevity is especially long, and depends on the preservation state. Avoid hot and humid places when saving.