Equality in a social context encompasses various aspects, including social justice, equality between genders, religions, and cultures, and the acceptance of diversity. With regard to the Kunstsammlung Nordrhein-Westfalen and the further development of its collection in the area of early modernism, the term “equality” is to be understood primarily as a goal with regard to the presentation of women artists, who had already played an important role in this period. In 1962, Werner Schmalenbach (1920–2010) acquired the first work for the Kunstsammlung Nordrhein-Westfalen: the painting Le métro aérien (1955) by the Portuguese painter Helena Vieira da Silva (1908–1992). Until the 1990s, she and Lee Bontecou (b. 1931), whose untitled sculpture from 1959/60 was added as a donation in 1971, remained the only women artists represented in the collection. This low number is shocking today, but much less evidence that there were no innovative and talented female artists at the time than that women were not perceived by the art world in the same way as their male colleagues because of their gender.

For several years now, women artists and their achievements have been honored in the Kunstsammlung Nordrhein-Westfalen through numerous exhibitions and acquisitions, and the strong disparity has begun to be corrected. Since 2017, roughly fifty percent of the exhibitions have thus been dedicated to women artists. With regard to acquisitions, the proportion of works by women artists has been substantially increased. In the current collection presentation, works by Helen Frankenthaler (1928–2011) can be seen alongside paintings by Mark Rothko (1903–1970). Hanging in close proximity to works by Kenneth Noland (1924–2010) and Jackson Pollock (1912–1956) are paintings by Carmen Herrera (b. 1915), a Cuban-American painter and pioneer of geometric abstraction in the United States whose oeuvre was featured in a comprehensive retrospective in 2017. Henri Matisse (1869–1954) meets Etel Adnan (b. 1925), while Wassily Kandinsky (1866–1944) encounters Nevin Aladağ (b. 1972). Recent acquisitions also include works by Lutz Bacher (?–2019), Cao Fei (b. 1978), Isa Genzken (b. 1948), and Lygia Pape (1927–2004).