Lithography, which has developed into one of the world's most popular processes for mass-producing images, was invented not by an engineer or a trained printer, but by a writer. The process, however, has its origin in a humble laundry list. Its inventor, Aloys Senefelder (1771-1834), was a struggling German playwright whose family had little money. Unable to afford the cost of printing his plays, he began to experiment with ways of engraving the manuscripts himself. Senefelder met with little success until one day in 1796, when, asked to take down a laundry list by his mother, he wrote the list in grease pencil on a polished limestone slab with which he had been experimenting. It occurred to him that he could use the water-repellent qualities of the grease coating to produce an acid etching on the slab. Over two years, he ultimately arrived at a different approach based on...