From the 1660s onwards, the lecture notes contain scientific engravings. These are very interesting for research, because they illustrate, among other things, how education was trying to connect with scientific discoveries and inventions.
Most of the printers of the engravings are known. Chronologically, they are: Hieronymus Tielemans (active from 1653 onwards), Lambert Blendeff (ca. 1650-1721), Michael Hayé (active after 1661), Petrus Denique (1683-1746) and his son Aegidius Peter (1717-1774) and C.H. Becker (active in the second half of the 18th century).
Firstly, the engravings offer visual information to the students who had to memorize the course material. There was, however, not always a clear connection between the text and the illustrations. Sometimes it seems as if some students just added engravings to their notes to make them look more attractive.
The engravings by Peter Denique contained astronomical and optical plates and appear to be linked to the information that the students needed to study for their exams. The link with the course material became even more clear after the curriculum reform in 1764. The course material was then replaced by new treatises and consequently, there was a need of new engravings. These were most often produced by C.H. Becker and were clearly designed together with some professors, like Jan Pieter Minckelers.