Two authors of books of etchings and drawings on what to see in Rome (Vedute di Roma or Views of Rome), Vasi and Piranese, were immensely popular with real and armchair travelers. Of the two, Giuseppe Vasi had the bigger sales: no upper class traveler would leave home without a lavishly bound copy. (New, specially commissioned bindings and/or thick, tooled leather slipcases were a necessity to show how rich you were, and, if it weighed more, the servants wouldn't complain.) Giambatista Piranesi for a while was a student of Vasi, but he struck out on his own after an argument. Although Piranesi was not as popular as Vasi in their own time, Piranesi's reputation has aged better, because he also produced volumes of illustrations for more specialized academic and architectural audiences.
Eventually, Vasi published a map and a series of "itineraries" for eight days in which the "Grand Tourist" could see all of the sites that Vasi had illustrated. There were hundreds, so doing Vasi's Roman itineraries might have been really exhausting -- and there were still ten more cities to see on the Grand Tour! But don't worry about the poor aristocrats. Most of them just sat in their carriages during mad dashes from site to site, and hardly any of them even got out of the carriage when they arrived. The idea was to see the thing, not to really visit and explore. In fact, the idea really was to be able to say that you had seen Rome, not necessarily to really do it. Lazier travelers might sit in cafes around the Piazza di Spagna, and, with their Vasi and Piranesi books in hand, listen to what their locally hired or fellow-traveling guides had to say about what they could have seen if they had the energy to ride around town. Those who were most vapid didn't even come down from their hired shaded carriages in the Piazza di Spagna: they had their drinks and guides brought to them. (Those carriages are still there for hire at exorbitant prices.)
When the travelers got home they would conspicuously display their books and repeat a few platitudes from the illustration captions. That and the vast assortment of souvenirs that many of the visitors brought home with them would ensure that everyone would know that they had made the Grand Tour and were truly upper class.
But why should we worry about these old illustrations? Well, first of all because they are interesting and precise views of many things that are harder to see today than they were 250 years ago: there has been lots of new construction since then and some of the sites are either no longer visible, no longer there, or remodeled past caring. Secondly, they can still serve the same purposes for which they were intended, introductions to sites yet to be seen and reminders we can take with us when the sad day may come when we have to leave the Eternal City.
The first impressions of Piranesi's and Vasi's works are almost all in Rome. Some are in the Vatican Museums, but a great many (hundreds!) of Piranesi's are in the long corridor outside the second floor apartments formerly occupied by visiting Cardinals at the Quirinale Palace. It's virtually impossible to get into that part of the Palace, and, even if you do get in, there's no way to ever get the time to really get a good look at them. A "first impression" is just what it sounds like -- the first image on paper made by a carved or etched block, and it's usually considered the best because there is no wear on the carving or etching and because first and early strikes were almost always supervised by the artist. It's possible to have more than one first impression if the artist makes more than one etching or block of the same view or if he reworks a block or etching to renew printing clarity. This is done to allow more copies to be printed -- Vasi had to do this because of his popularity, and there are subtle differences in the prints in consecutive editions. Reputable artists, including Vasi and Piranesi, were careful to mark their work to indicate that this had been done. Prints made from the same block are numbered and the best prints usually have lower numbers.
Unless you are an expert, it's considered wise to buy acknowledged modern reproductions. If you want to buy an early print (as opposed to a modern reprint) by any of the well known artists, be very cautious. Buy only from big houses and always insist on a written guarantee of authenticity with the ability to return the item for a full refund if it's later determined to be a fake. Reputable dealers routinely give such guarantees, but auction houses, even the biggest and best known, often do not. You might have really big money to spend, but be especially wary of any claims that a first impression is on sale -- they seldom come up for sale and when they do they are almost always sold from one collection to another, not on the open market. Really good modern fakes of old prints are rare -- counterfeiters have found there is a ready market for inferior fakes, so why make the effort to make good fakes? Older fakes are more of a problem: books of prints were very popular when they first came out, so counterfeits, even with the same paper and ink types, might be produced at the same time and city as originals were made. Some artists even brought suit against their own printers alleging that they copied etchings or printed extra copies -- thatâs another reason why art prints and art books were numbered. Finally, it's a truism that prints of Rome are more expensive in Rome than in other places. Better prices are often available in New York, London, and Munich (and these days, on the Internet) than in Rome.
Reprints of the Vasi and Piranesi books are available at better Rome bookstores and from Internet booksellers, but they too can be pretty pricey. Reproductions of prints from the original volumes and almost all of the drawings are available for free viewing on the Internet, although they are always, necessarily, of smaller scale than the originals, and that limits reproductive detail. Pretty good quality reprints can be made at home from some sites that give higher density views, especially if you are handy with a photo enhancement program.
Some quite useful Internet sites are:
Vasi's Map, divided into 16 tiles, each of which can be expanded by clicking a link below the map. The resulting larger scale maps show the numbers and names of Vasi's "views", and links below the maps lead you to corresponding pages where you can view the Vasi drawing and modern photos of the same site. It is at: http://members.tripod.com/romeartlover/Map.html.
Vasi's eight one-day itineraries with links to the same pages in the reference above: http://members.xoom.com/romeartlover/index.html
A modern Veduta di Roma from Kalervo Koskimies of the Sibelius Academy in Helsinki, Finland. Each link goes to a page containing old illustrations (Including Vasi and Piranesi) and modern (1999) photographs of sites in Rome. http://www.siba.fi/~kkoskim/rooma/pages/.
A site offering old Piranesi prints for sale at high, but market prices: http://www.allinsongallery.com/piranesi/