By no means all books printed during this period have survived. Natural disasters, wars and human carelessness have taken their toll here as well. In general, much has been lost of the printed matter that was produced in large impressions, such as ephemera and popular reading material. 'The more there were, the less there are', often seems to be the rule. We know, for example, of some almanacs, a genre which was brought onto the market in print-runs of 10,000 or more, only that they existed; not a single copy has survived.
The extant book production of the period between 1585 and 1725 is estimated at 125,000 to 150,000 different editions. There are, however, very few contemporary sources which provide insight into the number of book titles and editions which were published during this period; and those which have survived cannot claim completeness or bibliographical reliability. The only work which attempted completeness, at least in name, is the Catalogus universalis, a publication by the Amsterdam bookseller Broer Jansz, which covers the years 1639-1651. However, publications not distributed via the book trade such as occasional poetry, academic texts and official publications, and cheap and topical printed matter such as pamphlets, newspapers, almanacs and auction catalogues were not included, nor were, by any means, all publications meeting the criteria of the Catalogus universalis. Nevertheless, a cautious estimate based on this catalogue indicates that of the 'real books', the books which were bought in bookshops and which were retained after reading, more than 80% can still be found today. This percentage is also confirmed for the rest of the period from lists of titles from other sources such as publisher's lists and stock lists of individual booksellers, book auction catalogues, estate inventories, 'book lists in books' and suchlike.
Other figures certainly apply to the less regular books which were not or only occasionally referred to in the sources mentioned. It has been calculated, for example, that of printed auction catalogues no more than 10% has survived. As with other consumption books such as almanacs and occasional poetry, they were mostly thrown away after they had served their purpose. The loss of schoolbooks, music books, prayer books and suchlike is also large because they suffered greatly from intensive use. For the whole category of popular literature (prose novels, songbooks, 'real' literature in cheaper editions, and travelogues) there is often only a single copy known of a particular edition which means that whole editions have certainly disappeared entirely.
Old institutional libraries such as the university libraries collected of old primarily scholarly and scientific books and works by recognised men of letters. Devotional literature, sermons, cheap bibles, psalm books and 'Boeren-Catsen' (cheap editions of the work of Jacob Cats) were for a long time not part of their collection strategy. This also had a great influence on the survival rate. Political and religious pamphlets were considered from early on to be a major historical source and are therefore - in spite of their often tatty appearance - preserved in relatively large numbers. The editions of ordinances and proclamations were mostly intended for government bodies. They can still be found in large numbers in archives but to a lesser extent in libraries. Large contemporary private collections were often dispersed later.
