[3][4] He was a "friend and patron of many leading artists", from Picasso to Henry Moore and Wyndham Lewis,[5][6][7] and he played "an important role in spreading knowledge and appreciation of modern art" in Britain during the 1920s and 1930s.
[8] When Jäschke, a German citizen, was interned during the First World War, Zwemmer was left in charge of the business until 1918.
[4] Zwemmer's bookshop for a long period was the main place in London where modern and avant-garde art could be explored and where books and journals on the new artists such as Gauguin, Van Gogh and Matisse, and with the latest criticism regarding their work, could be obtained.
Zwemmer's was the only place in London where one would be "likely to see" livres d'artiste, Wyndham Lewis's The Enemy and Stanley Morison's typographical journal The Fleuron.
[6] The bookshop's display windows were famous for the bold imagery and the bright colours of the books and artworks on show.
[7] Sir Kenneth Clark and Sir Anthony Blunt both testified to the value of this bookshop in its early days to the "scholarly student of art history" while Henry Moore, John Piper and Graham Sutherland spoke of the "inspiration" its art books gave young sculptors and painters.
[4] They were often produced as international co-editions with distinguished European or American art publishers, which led to economies of scale and a great publicity exposure for the books.
[8][14] Through his gallery, as through his bookselling and publishing, Anton Zwemmer's constant goal was to "support the recent work of modern artists".
[4] In the postwar period the gallery promoted younger and emerging British artists including John Bratby[8] and Harold Cheesman,[3] the latter being a pupil of the English surrealist Paul Nash.