This work aims to revise the way we use and conceptualize manuscripts cartographic documents used in scholar research, especially because we rarely are able to distinguish they are originals or copis. In the Rio de la Plata area during the 18th and 19th centuries the manuscript copies were a part of the method of geographical knowledge transmition more adapted for always-scanty exchequer of the Spanish crown or the precarious institutional organization of the by-the-recently created Viceroyalty of the United Provinces. The copyists of maps were draftsmen or painters who knew the process of reproduction from "a uniform squared pattern to assimilate all the information of the original one". They started from a grid, on which the drown measured points that lead to the process of geometrical abstraction required in copying and producing maps. In this respect we consider that the Cartesian system served not onlyas a technical procedure, but also as a way of thinking and to know the mapped territory. Which are the parameters to determine the genuineness? Do copies lack of verisimilitude or public acknowledge? Maps were (and will continue being) defined less by its formal characteristics that for the particular conditions of its production and reception. This work is specifically focused on the copies for considering they celebrate his condition of immutabiles and they configure intellectual procedures of repetition that allow us to do or to change the ways of doing.