An optical copying device was likely used because the Valverde illustrations are mirror images of those in the Fabrica. The full title is Andreae Vesalii Bruxellensis, scholae medicorum Patauinae professoris, de Humani corporis fabrica Libri septem (Andreas Vesalius of Brussels, professor at the school of medicine at Padua, on the fabric of the Human body in seven Books).De humani corporis fabrica libri septem (Latin for "On the fabric of the human body in seven books") is a set of books on human anatomy written by Andreas Vesalius (1514–1564) and published in 1543.
The collection of books is based on his Paduan lectures, during which he deviated from common practice by dissecting a corpse to illustrate what he was discussing.
Dissections had previously been performed by a barber surgeon under the direction of a doctor of medicine, who was not expected to perform manual labour.
Vesalius's magnum opus presents a careful examination of the organs and the complete structure of the human body.
This would not have been possible without the many advances that had been made during the Renaissance, including artistic developments in literal visual representation and the technical development of printing with refined woodcut engravings.
Because of these developments and his careful, immediate involvement, Vesalius was able to produce illustrations superior to any produced previously. The first book constitutes about a quarter of the entire collection.