It sounds like a fairy tale when we talk about pencil and eraser in the era of computer where we write and delete with a stroke of key every now and then.But sometimes your past gives you more happiness through nostalgia than present and the same goes with pencil and eraser. To understand how eraser works we first need to understand how pencil actually writes on the paper.

Pencil leads are made up of "graphite" which is made up of carbon. The paper on which we write comprises of sticky fiber particles. When we write with pencil on the paper the graphite particle of pencil rub off and stick to the fibers of the paper.This sticky phenomenon forms the basic for eraser to work.

Erasers are basically made up of rubber. The rubber particles in eraser is more stickier than the fiber particles on the paper (it should be). So when the eraser is rubbed onto the pencil mark, the graphite sticks to the eraser preferentially over the paper, Erasers pick up graphite particles, thus removing them from the surface of the paper.Hence, eraser works because the polymers that make them up are stickier than the particles of paper -- so graphite particles end up getting stuck to the eraser instead.

Apart from rubber an eraser also comprises of sulfur to make it last longer,A softener, such as vegetable oil,usually added to make the eraser more flexible and Finally, abrasives, like pumice or quartzite, are added, along with dye to give the eraser a particular color.

When you rub an eraser across a pencil mark, the abrasives in the eraser gently scratch the surface fibers of the paper to loosen the graphite particles. The softeners in the eraser help to prevent the paper from tearing. The sticky rubber in the eraser grabs and holds on to the graphite particles.