I Demonstrated for the Illinois Watercolor Society in June, where I splashed paint on my Steam engine with a #16 brush to simulate rust and peeling paint. i did it small first before the demo to make sure it would work (11"x16"). I then demonstrated on a full sheet (22" x 30"). Here is the small one, the Demo and the finished peice (they look quite similar).
Peter Jablokow
Watercolor Artist