> The first thing that most people do when they look at a book is flip through it to see if it has pictures. In the hand press period, fully half of the investment in printing a book went onto its paper. If you wanted to substantially illustrate the book with engravings, it as much as doubled the cost of production.
Copper plate engraving was the most favored illustrative process from the late 1500s to the beginning of the nineteenth century. Here we see a copper-plate engraver at work, cutting away what would appear on the page (termed “intaglio” printing, as opposed to “relief” printing, done by a wood engraver, who cuts away what does NOT appear).
The heavy copper plates would then be used in a different sort of press, shown here. These printers were most often specialists, and therefore subcontractors, as it were.