You probably don't want to shine an ultraviolet light on your upholstered library furniture

A New Laundry Worry: Invisible Stains. (The New York Times, 2/14/2013)

Excerpt:    In a series of online-only videos shot in a mock documentary style, “Inside Dirt: The Dirty Truth About Your Clean Laundry,” a crusading filmmaker (played by the actor Jim Annan) declares what he calls “a state of detergency” and confronts consumers at places like gyms and laundromats. To demonstrate that clean-looking clothes may be soiled, he holds an ultraviolet light up to shirts, revealing spots primarily on armpits.



Oh, for those simpler days, when stains were visible.