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.
The Fust and Schoeffer device was printed in red and comprises two heraldic shields suspended from a branch. The shields bear a saltire (a diagonal cross) and a chevron surrounded by three stars. Perhaps these are based on Fust and Schoeffer's individual coats of arms.
Their mark was copied by — or it inspired — a number of other fifteenth-century printers, including, Gerard Leeu (1447–1492), Johannes Veldener (1475–1483), and Michael Wenssler (1493).
Most fifteenth-century printers' marks were relatively small and usually appeared on a title-page or accompanying a colophon at the end of the book. Perhaps the largest fifteenth-century example of a printers' device belongs to Erhard Ratdolt (1447–1528). His mark was first used from about 1494 in a Latin and German Psalter, long after he had left Venice and returned to his native Augsburg in south Germany. An entire page is devoted to his device, and in every instance that I have seen it is printed in two colors, black and red.
Center stage is a naked Mercury, a well-placed star (representing the planet*) affording him some dignity. He holds aloft a staff entwined by serpents, a caduceus. In Greek mythology, Hermes, son of Zeus, is depicted holding a caduceus. But in Roman iconography it is Mercury who bears it aloft. In addition to being messenger to the gods, Mercury, at least for the Romans, was also the god-patron of commerce and the merchant, thus lending his name to "mercantilism."
Although it appears that Ratdolt was the first to employ Mercury and the caduceus, a caduceus (and what I can only assume is Mercury's hand) was employed as a printer's mark in Basel by the printer-publisher, Johann Froben (ca. 1460–1527) from about 1516, and earlier by Johannes Tacuinus in Venice from about 1505.
Ratdolt's mark undoubtedly influenced Peter Liechtenstein, another printer in Venice in the subsequent century, whose own device resembles Ratdolt's both in scale and design.
One of my favorite printers' marks is that used on some title-pages by the brilliant Simon de Colines between 1520 and 1527. A beautiful scene of a family of rabbits frolicking at the base of a tree. Why rabbits?
Kay Amert (2012), p. 17.
For Melchior Sessa of the Venetian Sessa publishing dynasty, a cat (perhaps the resident print-shop kitty) was the centerpiece of his printers' mark.
From the last quarter of the fifteenth century we begin to witness a steady separation of the facets of the 'book industry' into distinct practices of printing, publishing, and bookselling. Nowadays, very few printing companies, save a number of letterpress shops, use a printers' mark. Instead the printers' device, despite the nomenclature, is most commonly employed as a 'publishing mark', the Penguin of Penguin Random House, being perhaps one of the most instantly recognizable contemporary examples.
And however it is used today, and whether it is a rabbit, a penguin, or a cat, it all began more than 500 years ago with Gutenberg's industrious and talented successors, Schoeffer and Fust.
Kay Amert (2012): The Scythe and the Rabbit: Simon de Colines and the Culture of the Book in Renaissance Paris
* In medieval and Renaissance astronomy the planets and stars were all alike labelled stars, although they were separated into two groups: The fixed stars (what we today call stars) and the wandering stars, or planets. The word planet is from the Greek 'astēr planētēs' (ἀστήρ πλανήτης) meaning 'wandering star.'
Caduceus is encoded in Unicode at code point U+2624. ੀ