A vintage Helen Frankenthaler, American, 1928 to 2011, exhibition poster for her show in 1969 at the Whitney Museum of American Art. Framed. Helen Frankenthaler, an abstract expressionist painter, was a major contributor to the history of postwar American painting. Having exhibited her work for over six decades from the early 1950s, she spanned several generations of abstract painters while continuing to produce vital and ever-changing new work. American Abstract Art Poster Collectibles.