Druckermarke des Peter Schöffer am Ende von Valerius Maximus, 1471 (Wikipedia)
The very first printers’ mark or printers’ device dates back almost to the very beginning of Western typography. In Mainz, Fust and Schoeffer, employed a printers’ mark in a Bible that they published in 1462. There is an earlier example in their Mainz Psalter of 1457, though many now believe that it was perhaps stamped in at a later date. Either way, Fust and Schoeffer are the first printers to use such a device, a kind of trademark that was employed to guard against piracy and that served as a seal of quality. …
Dazu weiters http://ilovetypography.com/2015/03/22/the-first-printers-mark/
Siehe auch: http://de.wikipedia.org/wiki/Druckermarke