It was the son of a designer and sign painter in leipzig, germany, who applied the new design approaches to a wide audience of printers, typesetters, and designers through his book die neue typographie (the new typography).

It was Jan Tschichold, the son of a designer and sign painter in Leipzig, Germany, who applied the new design approaches to a wide audience of printers, typesetters, and designers through his book Die Neue Typographie (The New Typography).

Explanation:

Jan Tschichold was a German typographer, author of the work Die neue Typographie (The new typography) that laid the foundations of the current typography, possibly being the most famous book on the subject of the twentieth century.

With the passage of time the avant-garde movements caught his attention and it was then that he began to see the typography from another point of view and even in 1925 he published an article called Elementare Typographie in the magazine Typographische Mitteilungen where he explained a series of principles or beliefs that he had developed himself.

In Munich he made several posters for cinema and in 1928 he designed and published his first book called Die neue Typographie. This book was mainly directed towards typographic designers and it exposed some of the main principles of the modern movement in relation to typography.

b) to encourage free trade