How did printer’s marks and colophons identify early printed books?

In the early days of printing, identifying the origin and production of a book relied on two primary devices: the colophon and the printer’s mark.12

The Colophon

The colophon was an inscription placed at the end of a book that served as a vital record of its creation. Printer-publishers used these entries to document the location and date of publication, assert credit for their work, and occasionally advertise the merits of the volume. In some instances, printers even used the colophon to protect their property rights against rival publishers. While early colophons were simple statements of fact, they eventually evolved into more elaborate essays that included prefaces or dedications.12

The Printer’s Mark

The printer’s mark was an identifying device, such as a monogram or emblem, included in the book to signify the printer's identity. Used from the very beginning of the typographic era, these marks provided a visual signature for the printer-publisher.12

By approximately 1480, some of the information traditionally found in the colophon began to shift to the front of the book, eventually leading to the development of the title page.12