Where both are available to the watercolourist, is there anything to choose between hard or soft water?

Ian King replies: Water quality varies enormously across the country. Artists living in hard water areas often use wetting agents to help their washes flow more evenly. In soft water areas, washes should flow perfectly well without any additional help. One important note: never resort to using detergent or water softener as a wetting agent - these will completely destroy the gelatine sizing on your paper surface, leaving it resembling blotting paper.