Interesting discovery re: Gutenberg
Based on computer analysis of his first printed books, this study argues that, while he invented moveable type (in the West), he didn't make the full breakthrough to using copper moulds to easily create the lead type. Rather, each lead character had to be hand-crafted in plaster before being cast. Since you needed a fair number of them, and they wore down in use, Gutenberg's process was far more efficient than hand-copying, but still rather expensive and slow.
The authors suggest that the use of metal molds actually was invented by another printer, in Italy, about 20 years later. You cut an iron die of the letter, hammered it into copper, and used the copper to cast the lead character. Now you could get characters as fast as you could pour lead, and one shop could furnish type for many presses.