The line is pencil, and the wash is ivory black watercolor mixed with water in a film can, whose snap-on lid never leaks. It’s one of the easiest ways to get started with painting on the spot, because the tools are so simple. It all fits in your pocket.
May I show you a page from my wife Jeanette’s sketchbook? The line is from a ballpoint pen, and the washes are raw sienna, ultramarine, and burnt umber watercolors. She was thinking of the colors that John Singer Sargent used in his Venetian watercolors (too bad it's Poughkeepsie, not Venice). To see more Sargents, visit the post on “warm and cool.”