Including trademarks in books became crucial after the invention of the printing press; without stringent copyright laws, rival publishers could repurpose superiorly edited texts with impunity. Aldus Manutius of Venice, who employed Erasmus as a proofreader, called attention to his company’s “sign of the dolphin wound round the anchor.” Florentine printers were aping the mark, but in the frauds, “the head of the dolphin is turned to the left, whereas that of ours is well known to be turned to the right.”