Fiberglass eraser refill Erase ink on transparent paper Removes small rust stains (e.g. in the car and at home) Round tip The quality of an eraser and using the correct eraser are crucial for optimal results. Basically, two different materials are used to make erasers: rubber and plastic. All rubber erasers and most plastic erasers manufactured by Faber-Castell are PVC free. Faber-Castell PVC-free erasers do not contain phthalate which is a harmful plasticizer. Phthalates have been found to cause several undesirable effects when exposed to the human body. The balanced plastic blend ensures smooth, smear-free erasing.