The great architectural etchings of Giovanni Battista Piranesi are significant in the history of art for several reasons. In the first place, Piranesi’s enthusiastic celebration of the ruins of Imperial Rome provided an important impulse in the preservation and restoration of important architectural sites. His views of Rome also document the development of Baroque Rome. Secondly, his dynamic vision of classicism contributed richly to the emergence of the classical style in the 18th and early 19th centuries. His friendship with Robert Adam provided a direct link between his aesthetic and the development of British architecture and decorative arts. Finally, Piranesi commanded a graphic technique that remains unsurpassed, and his finest plates reveal the communicative force that is possible in this medium. Piranesi is best known as the visionary and imaginative artist of the famous Carceri (stylized romantic prisons), but in his time he was an architect, archaeologist, and antiquities dealer as well. He established a studio for the restoration of Roman antiquities and functioned as a dealer, all the while etching magnificent renderings of the items he purveyed. Piranesi made sketches directly on the site of those famous scenes represented in his magnificent views of Rome. He would mark the play of light and shade at various times of day and would also return to these sites to study the appearance of the structures in the softer light of the moon. The sketches he produced on site are mere indications, realized in a kind of visual shorthand that would stimulate his memory when he began work on the actual process of etching. Before beginning work on the copperplate itself, he would prepare a loose drawing, the size of the etching, in which he would mark out the basic parts of the composition. He would then either trace this drawing onto the copperplate or prick through the paper to the surface, which he had coated with varnish, wax, and linseed oil.