After 1490 the number of printers and stationers increased rapidly. Panzer enumerates no fewer than eighty-five printers, and nearly 800 books executed during the fifteenth century; and there is no doubt that his estimate is considerably under the mark. The most important productions of the Parisian press at that time were service-books, of which enormous numbers were issued. The best known publisher of such works was Simon Vostre, who, with the assistance of the printer Philip Pigouchet, began to issue _Books of Hours_, printed on vellum, with exquisite borders and illustrations. These books began to be issued about 1488, and commence with an almanac for the years 1488 to 1508. In many cases the printers did not take the trouble to make new almanacs, but were content to copy the old; indeed, we find the same almanac in use ten years later. This has led to a great deal of confusion in the bibliography of the subject, for it is a common custom of librarians and cataloguers to ascribe the printing of a book of this class to the date which occurs first in the almanac, when there is no date given in the colophon. The most celebrated publishers of these books were Simon Vostre, Philippe Pigouchet, Antoine Verard, Thielman Kerver, Gilles Hardouyn, Guillaume Eustace, Guillaume Godard, and François Regnault. Vostre and Verard do not seem themselves to have printed, but were merely publishers, far the most important printer being Pigouchet. Of the nine or ten _Books of Hours_ for the use of Sarum, printed abroad during the fifteenth century, Pigouchet probably printed half, and all but two were printed in Paris. In examining early foreign-printed English service-books, it is curious to notice that while nearly all the _Horæ_ were printed at Paris, the majority of Breviaries were printed at Venice, and only two at Paris. No _Horæ_ is known to have been printed at Venice. The end of the century saw the commencement of the celebrated Ascensian press, the rival in some ways of the Aldine. The founder, Jodocus Badius Ascensius (Josse Bade of Asch), was a man of great learning, and was for a time professor of humanity at Lyons, and press-corrector to Trechsel, whose daughter he married. Trechsel died in 1498, and in 1499, at the invitation of Robert Gaguin, Badius came to Paris and established himself there as a teacher of Greek and a printer. It was not, however, till 1504 that the Ascensian press became important.