Greta Hällfors-Sipilä's (1899-1974) production is characterised by colour-intensive watercolours and drawings in a naive spirit. She painted mainly landscapes, but also still lifes and interiors. She was influenced by impressionism, cubism, the Russian avant-garde and neo-primitivism, and artists such as Henri Matisse and Marc Chagall, among others. Hällfors-Sipilä was long overshadowed by her husband, the artist Sulho Sipilä (1895-1949), and it was not until later that she achieved the appreciation of art critics. Subsequent research has shown that Sulho Sipilä signed some of Greta's works in his own name.

Greta Hällfors-Sipilä was diagnosed with schizophrenia in 1946 and was admitted to the Kellokoski mental hospital, where she remained until her death.