In comparison to the previous period, private libraries were usually of a narrower and less universal scope due to changing standards in research and collecting, the increase in scholarly,scientific and other books, and the growing significance of institutional libraries (Koninklijke Bibliotheek, university libraries, town libraries, and libraries of associations and societies).

Humanities libraries focussed on the Greek and Latin classics, the Bible and the Church Fathers, in the form of manuscripts, first editions and annotated text editions. This ideal gradually gave way to a less static and uniform type of library in which the modern languages (such as Dutch literature and history) played an important part.

Latin thus lost its position to the vernacular as the most important language: Dutch became the first language, followed by French, German and, at a later stage, English. This also implied that an increased proportion of books came from the Netherlands (or the Low Countries).

In addition to libraries of professionals (such as that of the medical doctor H.C. à Roy), collections were formed by collectors who specialised in one or more fields: alba amicorum, autographs by famous persons, bindings, Elzeviers, children's books and popular books, pamphlets, plays, etc. Several of these collections explored new fields, a development also stimulated by the antiquarian trade with its thematic catalogues of a high bibliographical level (Frederik Muller). This development obviously led to a rise in price of hitherto unknown and unloved works and less wealthy new collectors shifted their field of activity.

The most extraordinary collection of this period is possibly that of Baron Van Westreenen (1783-1848) of The Hague, who not only by his clothes, but also by the character of his collection (combining medieval manuscripts and early printed books from all over Western Europe with antique coins and Egyptian, Greek and Roman antiquities), showed that did not follow the fashion of his days. For half a century, he managed to ignore, with a tenacious perseverance, the changing trends, pursuing a goal that would have been ambitious even for an institutional library, resulting in a museum founded by him that to this very day commands astonishment and admiration.

Our knowledge of private book collections in this period is based essentially on some library catalogues and on the numerous auction catalogues usually drawn up after the death of the owner. Research has been conducted primarily into private collections that have been integrated entirely or in part in institutional libraries.

Little is yet known about the books owned by the less fortunate. It is clear, however, that in the second half of the nineteenth century the increasing degree of literacy and declining book prices made it possible for increasing numbers of people to build their own, generally modest, libraries. The Wereldbibliotheek, a society for good and inexpensive reading matter, founded in 1905 by Leo Simons was in keeping with this development.