Knowledge of ballpoint pens
The life of the written character
Oil is said to have more than 50 years when it is a normal storage state as a document. At present, it has been more than 50 years after the release of ballpoint pen , but the documents of those days are still present. However, please note that it becomes thin in about six months when it is a place in direct sunlight.
Because the pigment ink of the water and the neutral is the same ingredient as “ink”, it is expected to have in hundreds of years.