Uncovering the Science Behind Erasers: Why Do They Only Work for Pencil Marks?

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    Eraser Work
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Erasers work by rubbing graphite off the surface of the paper, as graphite sits in a thin layer above it. Unlike graphite, ink penetrates the paper, making it impossible to erase without damaging the surface. The rubber material of erasers provides good traction, effectively gripping the graphite to remove it. This traction is similar to how tires grip the road. Therefore, erasers are specifically designed to work with pencil marks but not with ink.
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How does an eraser (rubber, for non-US) work? Any why it works only for pencil(or graphite) , not for pen?
 
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jobyts said:
How does an eraser (rubber, for non-US) work? Any why it works only for pencil(or graphite) , not for pen?

the eraser rubs the graphite off the paper. graphite is a solid and sits on top of the paper (in a thin layer). that's why you can rub it off without destroying the paper underneath.

You can't rub off ink, because it dyes the paper--i.e., gets below the surface of the paper.
 
And rubber is used for the same reason it is used in bicycle and automobile tires; because it has good traction. It "grips" the graphite just like tires grip the road.
 

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