Becoming a half-orphan at an early age, Lohse grows up in poor conditions. He gets by with occasional jobs, and from 1918 to 1922, he completes an apprenticeship as an advertising illustrator under Max Dalang. At the same time, he attends classes at the Kunstgewerbeschule Zurich. Yet, he cannot realize his dream to study art in Paris. In the 1930s, Lohse becomes one of the pioneers of modern Swiss graphic art; as a graphic artist and book designer, and as a painter he works on curvatures and diagonal constructions at this time.

In 1937, he and Leo Leuppi found the artist group allianz, to which Camille Graeser also belongs. Throughout his life it is important to him to bring together architects, graphic artists and artists in associations and groups to promote the socio-political importance of culture. During World War II he is also politically involved in the resistance and supports emigrants through illegal activities. Additionally, he is part of an antifascist organisation. Artistically, he develops standardised pictorial means during the war: additive vertical rows, rhythmic, serial structures, equality of colour quantities, modular orders. After the war he participates in numerous exhibitions, biennials and the documenta, and organises exhibition formats himself. He often designs books and magazines and is responsible for their editing. In 1962, he becomes a member of the exhibition commission of the Kunsthaus Zurich.

In the course of his career he has received various Swiss and foreign prizes and awards for his art and for his political commitment to art and culture. These include his appointment as Commandeur de l’Ordre des Arts et des Lettres de la République Française by the Minister of Culture. In 1987, one year before his death, the Richard Paul Lohse Foundation is established in Zurich.