A printer's mark, device, emblem or insignia was a symbol used as a trademark by early printers starting in the 15th century.
The first printer's mark is found in the 1457 Mainz Psalter by Johann Fust and Peter Schöffer. One of the most well-known old printer's marks is the dolphin and anchor, first used by the Venetian printer Aldus Manutius as his mark in 1502.
The database Printers' Devices of the Ancient Book Section of the Library of the University of Barcelona, was launched in October 1998. The University of Florida libraries also provide digital access to printers' devices and include The University of Chicago devices that have appeared on the cover of their publication The Library Quarterly. 
Printers' devices have been incorporated in American library buildings, as a reflection of the British Arts and Crafts Movement.