The first two of these oil sketches were originally on one large canvas with five others (Late Gallery 2959, 2990-2, 3026); the compositions were separated in about 1914. The others come from nine further examples similar in style, technique and type of canvas (Tate Gallery 3380-8) which are not recorded as having been originally joined. The I856 Schedule of the Turner Bequest does, however, list four 'Roll[s] containing 4 subjects': , only two of which are accounted for by the Cowes sketches, one of which in fact contained five compositions (see Nos.311-19); the other two rolls could have been that mentioned above together with one containing the other sketches. In addition the second group of Italian sketches shares with the first the peculiarity of having been tacked to some sort of stretcher or support from the front, Turner having gone over the tacks with paint in the process of painting each composition. This suggests that in both cases a large piece of canvas was remounted on a relatively small support each time Turner wanted to paint a new sketch.

Those landscapes that can be identified are Italian and the first sketch was used for the large picture exhibited at the Royal Academy in 1829 (No.482). It seems likely that they were done in Italy during Turner's second visit in 1828-9, the use of large rolls of canvas being presumably for ease of transport as seems to have been the case with the Cowes sketches. However, the canvas is not identical with that of the pictures that were exhibited by Turner in Rome (see Nos.4724), nor did those pictures reach London, having been sent by sea, until after the opening of the 1829 Academy exhibition, but Turner would not have needed the 'Polyphemus' sketch directly in front of him to paint the large picture.

Unlike the Cowes sketches, which seem to have been the direct result of specific experiences even if they were not painted on the spot, these works are essays in composition; even those based on actual landscapes are already of places known to Turner from his travels in Italy in 1819 if not from pictures by other artists: both Lake Nemi and Tivoli (for which see Nos.B35-6) had been painted by Wilson. They are studies in broad areas of strongly contrasted tones of flatly applied colour, occasionally enlivened, as in the case of Lake Nemi, by a flurry of heavy impasto. The subjects range from recognisable Italian landscapes, through the Polyphemus' sketch which uses landscape motives based on what Turner could have seen in Italy, to the Claudian sea-port which depends entirely on his knowledge of the work of another artist. Differing in size one from the other, and not adhering to any of the standard sizes usually used by Turner, these are works that can definitely be described as sketches rather than unfinished' paintings which could have been carried further. For a work very similar in composition and, it would seem, date, but of quite different purpose see ‘Rocky Bay with Figures’ (No.483).