You can read more about Master Copies here, but essentially the idea of a master copy in art is to try to reproduce the artwork of an artist that you like in order to better understand why they drew/painted the artwork in a specific way. The idea isn’t just to replicate but to learn by doing this and thus grow as an artist. I must admit I’m skeptical as to whether or not this will actually work, but I’m willing to give it a shot anyway. These drawings were made with a combination of brush/fountain pen, and are the work of mangaka Hiroshi Hirata in book 2 of the Satsuma Gishiden.
Master Copies : Satsuma Gishiden