Gertrude Barrer studied with Will Barnet at the Art Students League in the mid-1940s and in 1946 exhibited with the Indian Space painters in the "8 and a Totem Pole" show at Gallerie Neuf. Reviewing her first solo show at the gallery in 1947, Clement Greenberg praised Barrer as "one of the most promising painters in the country."
During the late 40s Barrer served as art editor of Iconograph magazine, one of the earliest of the artist-run magazines.

Barrer's abstracted forms were invariably based in nature, even as they became increasingly expressionistic. Her work was included in the 1950 Whitney Biennial and Samuel Kootz'"New Talent" show in 1951.