How can an eraser erase writing?
If you look at a pencil drawing with a magnifying glass or a microscope, you will see fine pencil grains lined up in rows on the paper.
When the eraser is used to rub the surface of the paper, the fine grains of pencil on the surface of the paper are rubbed away, and the writing is erased.
In the case of writing with a ballpoint pen or sign pen, the ink penetrates not only the surface of the paper but also the inside of the paper, so no matter how much you rub the surface with an eraser, the writing will remain.
By the way, there are two types of erasers in use today: rubber and plastic.
The rubber erasers erase by scraping off the surface of the paper, while the plastic erasers erase by grabbing the pencil by the pencil's grain.
Today, most of the erasers we use are made of plastic. The name "eraser" seems strange for a product made of plastic, so these days it is often called a "character eraser.
