Representation consisting of a copy (as of an engraving) made by laying paper over something and rubbing it with charcoal WordNet 3.0 & Open English WordNet

A rubbing is a reproduction of the texture of a surface created by placing a piece of paper or similar material over the subject and then rubbing the paper with something to deposit marks, most commonly charcoal or pencil but also various forms of blotted and rolled ink, chalk, wax, and many other substances. Wikipedia

An art technique Wikipedia Disambiguation

An impression of an embossed or incised surface made by placing a piece of paper over it and rubbing with graphite, crayon or other coloring agent. Wiktionary

Impression of an embossed or incised surface. Wiktionary (translation)