There isn't much documentation about Giovanni Grevembroch, but we know he was probably born in Venice, in a family of Flemish origins (van Grevenbroeck), all of them being painters or draftsmen, although of modest results and recognition.
Pietro Gardenigo, a noble Venetian, established himself as Grevembroch's patron, when he was just a 23 year old artist, and gave him hospitality (and a salary, I imagine) for quite a bit of time.
Gardenigo himself was sort of an historian, keeping a diary all along his life of what he was seeing happening in Venice, and put together 38 volumes (Notorii) plus 26 volumes (Commemoriali) of relevants events in Venice to which he had attended in person.
This help/collaboration allowed Grevembroch to take the time to prepare what is known to be his main accomplishment, to which he dedicated 20 years of his watercolor painting.
In the four volumes that came out there is a collection of watercolors and commentaries about how the people in Venice dressed, for work and leisure, and not only the noble classes, but just about everybody.
A total of 648 watercolors, with commentary for each image, collected in the four books of "Gli abiti de veneziani di quasi ogni età con diligenza raccolti e dipinti nel secolo XVIII"
Giovanni Grevembroch's work can be found at the "Biblioteca Civici Musei Veneziani - Museo Correr" in Venice.
