 At one time Kaplan was supervisor of design in a glassware factory and this gave him an interest in the third dimension which was later to blossom in his ceramics and sculptures.From the 1950s onwards Kaplan's artworks concentrated on Jewish themes, despite constant and often serious opposition and obstruction from the Soviet cultural authorities.Amongst these works are his cover and illustrations to the "Jewish Folksongs" of Dmitri Shostakovich (1977), illustrations to Aleichem's "Tevye the Milkman" (3 series, 1957–1966), "The Enchanted Tailor" (1954–57) and "Song of Songs" (1962), and an extensive series of coloured lithographs (printed in London in 1961) on the old Jewish Passover song "Chad Gadya" ("One Kid Goat").