The establishment of the Republic did not bring about any change in the practice of piracy which was quite usual in the Dutch book trade as well. On the contrary, pirate printing increased in proportion to the rapid growth in book production during the Golden Age. In as far as the reprinting of foreign books was concerned, this activity actually contribute greatly to the international success of Dutch publishers. Many foreign titles of all genres were reissued here shortly after they appeared, but the most lucrative were publications which could be sold in large numbers on the market abroad, such as bibles, editions of the classics and French novels and plays. Pseudonyms were often used for the reprinting of foreign works which gradually gained the status of a trademark. One of the best known pseudonyms used by Dutch printers in this period was that of the fictitious publisher from Cologne, Pierre Marteau.

Of course, Dutch publications were also reprinted abroad, but most damage was done by domestic pirated editions. There were various motives for this. For some publishers it was a way of earning a living. Others used piracy to undermine the competition or to pursue personal vendettas of which the piracy war between the Amsterdam booksellers Blaeu and Janssonius in the first half of the seventeenth century was a prime example.

People were not, however, defenceless against these practices. In addition to the usual countermeasures such as lowering the price of one's own edition or the inclusion of a printer's device, the author was sometimes asked to place his signature as a hallmark. Another novel strategy of defence was to publicise the names of pirates in advertisements in newspapers and journals. The traditional weapon of retribution was given new meaning when publishers made collective agreements. In 1660, a bookseller from The Hague and thirteen of his colleagues from Leiden entered into an agreement to counteract piracy; in 1710 a large group of printers and booksellers from five cities entered into a similar contract.

The only legal protection of copyright offered in the Republic, was by patent or privilege. Up until the mid-seventeenth century the States-General were the major issuing body of privileges. The patents of the States-General offered protection against reprinting within the territory of the Republic, but were usually valid only for a few years. Transgressors were punished by confiscation of their editions and a fine. As a result of a conflict over the patented edition of the Dutch Authorised Version of the Bible, the Statenbijbel (1637), the provinces began to issue more and more privileges. Holland, the province in which most publishers were established, gradually took over the position of the States-General. The duration of the privilege was set at fifteen years and the fine at 300 guilders. The privileges of the other provinces and the patents issued by the towns generally only related to books with a regional or local appeal.

Privileges were mainly requested for publications publishers had high expectations of or which had proven successful in the past. The number of books patented by the States-General and the States of Holland for the period 1585-1725 amounted to no more than a few thousand, a modest portion of the total book production. Among these were, moreover, many renewals.

A major difference from the provision of privileges elsewhere was that the patents in the Republic were seldom used as a form of preventive censorship. Obtaining a patent was not mandatory, nor was the publisher able to derive official approval for the content from the privilege issued. The privileges were only meant as a protection of copyright. In dubious cases, however, the opinion of a competent authority, such as a theological faculty, was sometimes requested. Refusal to allow a privilege was in most cases due to the advice of a local booksellers' guild if granting the privilege was considered to infringe the rights of another publisher.