Knowledge of erasers
Can you erase the character of a ballpoint pen ?
These days I often see an Plastic Eraser that can erase the ink of a ballpoint pen like a pencil. This is how it is erased on earth, and the ink of the ballpoint pen is scraped off the paper. Therefore, the paper becomes hangnail after erasing it.
Because the abrasive particles contained in the sand are coarse, they play a role like sandpaper. In our company, ES-510, 512N is put out in the sand.
The usual Plastic Eraser is “stick and take”, but in this case, “cut and take”, the paper becomes thinner that minute.