Rubber is the most abundant ingredient found in erasers. It can be either natural or synthetic, depending on the type of eraser. Natural rubber comes from latex, which is produced by a tree called Hevea Brasilienesis. Synthetic rubber, on the other hand, is made up of a combination of many different chemicals including styrene and butadiene.
Sulfur is a very important substance in erasers because it helps the rubber become stronger and more resistant to heat. Without this, erasers would melt easily when exposed to direct sunlight.
Vegetable oil is added to erasers because it softens the rubber and makes it flake away easily. This way, when the eraser is rubbed on a piece of paper, the dirty rubber is left behind and discarded.
Some erasers have different ingredients in them that make them perform a wider variety of functions. For example, to remove stronger marks such as ink, pumice is added to the rubber to make it more stiff and abrasive. All erasers also include some type of pigment to determine their color. White is produced by adding a zinc titanium oxide, and red is produced with an iron oxide.