Cock specialised in the documentation of classical antiquity. His series of Roman ruins, including multiple views of the Colosseum and the Forum of Nerva, introduced the architecture of Rome to a Northern audience. These etchings and engravings use precise line work to record the decay of ancient structures. He often included small figures to provide a sense of scale against the massive stone arches. His work focused on topographical accuracy rather than idealised compositions. This approach created a new standard for architectural printmaking.

Modern collectors value Cock for his clear, architectural style. His prints of Roman ruins provide a sense of historical perspective and structural balance. The monochromatic nature of his engravings allows them to fit into contemporary interior designs. These works offer a connection to the origins of European print culture and the early fascination with archaeology. They remain popular because they combine technical skill with the quiet atmosphere of ancient sites.