As the rubber grabs the graphite particles, small pieces of combined rubber and graphite get left behind. Do you feel them getting warmer the longer you rub? The warmth you feel is the heat generated by the force of friction created by the rough surfaces of your hands rubbing together.Īs the abrasives in your eraser are rubbed against paper, friction produces heat, which helps the rubber become sticky enough to hold onto the graphite particles. Try rubbing your hands together right now. The sticky rubber in the eraser grabs and holds on to the graphite particles.Įrasers work because of friction. The softeners in the eraser help to prevent the paper from tearing. 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. Finally, abrasives, like pumice or quartzite, are added, along with dye to give the eraser a particular color. The rubber is usually combined with sulfur to make it last longer.Ī softener, such as vegetable oil, is also usually added to make the eraser more flexible. While pencils are filled with graphite, erasers are made mostly of rubber, although plastic and vinyl are sometimes used. When you write with a pencil, graphite particles from the pencil rub off and stick to the fibers of the paper you're writing on. It's actually a mineral called ' graphite,' which is made up of carbon. Although we call the black stuff in pencils “ lead,' it's not the real metal known as lead.

Have you ever stopped to think about exactly how that little pink piece of rubber at the end of your pencil is able to erase what you've written? Is it magic? Nope! There's a perfectly logical, scientific answer.īefore we get to how erasers work, though, let's learn a bit about what exactly is on the paper that you're erasing. The important thing is to learn from them… and erase them as soon as possible once you spot them!

Oops! Not quite… now where did I put that eraser?

Eraser