Koreans set up "Juja Printing House", type manufacturing and printing organ, in 1403, rapidly developing printing technology by mass-producing different kinds of metal types.

They were the first in the world to produce lead type in 1436.

They distributed types on copperplates before accurately fixing them. This printing technology gave an origin to the modern typesetting.

The True Record of the Ri Dynasty says in this regard: The sizes of the copperplate and types are so consistent with each other that hundreds of papers can be printed accurately in a day.

An exhibition called "History of Books" was held in Paris under the sponsorship of UNESCO in 1972.

The ancient book "Jikjisimgyong" on display there testified to the fact that Korea was the first to invent metal type and the printing technology was disseminated all over the world from Korea.