But that was not the case in the past.
In the old days, there were no erasers, but instead, people used "bread crumbs. It is astonishing that people used food to erase letters.
However, about 250 years ago, a British scientist named Priestley discovered that rubbing a rubber on a pencil erased the letters.
Later, improvements were made, and the eraser as we know it today was created. As the name suggests, rubber is the main material used to make erasers. First, raw rubber from rubber trees is thoroughly kneaded. Then, sulfur, plant oil, and various other ingredients are mixed in, left for a few days, and further kneaded. The mixture is then stretched into a long stick shape, and finally mixed once more with sulfur and heated to produce the final product. The eraser is made by cutting it into pieces of appropriate size.
Recently, however, erasers called "plastic erasers" have become more common. This is a new type of eraser made mainly from plastic, unlike the erasers mentioned above. Plastic erasers are more convenient than rubber erasers because they can be easily colored and scented.