When was guttenbergs invention of the printing press and movable metal type allowing mass production books?

Johannes Gutenberg did not invent the printing press. The printing press was invented in China centuries before Gutenberg.

Gutenberg's innovation was movable metal type. This allowed for the mass production of books by making it easier to set and reuse individual letters.

While the exact date is disputed, Gutenberg's invention of movable metal type is generally accepted to have taken place around 1440.