An eraser is a fixed knife with a total length of approx. 15 cm and a " convex " (rounded) blade, which is often double-edged in the front area. The handle can be made of wood or plastic and is often widened at the end in order to smooth the machined area.
Erasers are also popular for fine cutting work.
The use of an eraser requires skill in handling in order to damage the writing / drawing carrier as little as possible and to carry out the "shave" as inconspicuously as possible. It is also required that the user is able to keep the knife in a sharp state or to sharpen it.
- Helmut Winkler: Technical drawing, device and machine drawing. Fachbuch-Verlag, 1966, page 28.