Around 1950 Bo moved to Paris. There he studied printmaking techniques under Stanley William Hayter, director of Atelier 17. 

Beginning in 1952, Bo produced etchings and aquatints as illustrations for books by many renowned authors including Victor Hugo and Hans Christian Anderson. In the mid 1950s. Bo began exhibiting his individual prints and paintings in Paris and began working as an illustrator for the French magazine, Le Monde. Having internationally established his reputation as a printmaker by 1960, Lars Bo exhibited his work in England, Japan and the United States.