I don't like to use hair dryers at all. On most of the papers I typically use, I will just let them dry under a window fan set to 'low'. The only exception I make to this is when I use papers that seem too absorbent, and you need to dry the coating before it sinks too deeply into the paper fibers. In general papers that sink in the wash fall into this absorbent category, while papers that float in the wash do best if you just let them dry at ambient temperature under a little moving air.