Einar Jolin is best known for his Expressionist and slightly naive style. In 1908, after studying at Konstfack, the big art school in Stockholm and at Konstnärförbundets målarskola, Jolin went to study at Henri Matisse's academy in Paris, together with two of his artist friends, Isaac Grünewald and Einar Nerman. He remained there until 1914 when he returned to Sweden.
Jolin was credited with bringing Expressionism to Sweden. But his style developed differently from traditional Expressionists, in that he simplified his motifs in an almost primitive way, painting an imagined reality rather than raw emotions. His paintings of Stockholm during the 1910s and 1920s in his trademark naive style, many of them using a soft grey palette, are now highly sought after. In 1915, the Hewarth Walden gallery, Der Sturm in Berlin, presented an exhibition, Schwedishe Expressionisten (Swedish Expressionism). Jolin participated with six paintings, three of which were vistas of Stockholm.
Jolin continued to travel extensively including to Africa and the West Indies but he particularly loved the Mediterranean notably Capri which he visited on several occasions and where he also exhibited his work. Jolin usually stayed at Villa San Michele, the home of well-known Swedish doctor and psychiatrist, Axel Munthe.
Jolin had several exhibitions at Stockholm's main contemporary art gallery, Liljevalchs konsthall in Stockholm and in 1954, he toured the United States with an exhibition. Dag Hammarsjöld purchased one of his works for his office in the United Nations building.