In the course of the acquisition of the collection of Dorothee and Konrad Fischer, the archive was also donated to the Kunstsammlung Nordrhein-Westfalen. The archive includes business correspondence, letters from artists, photographs, and printed materials that once belonged to Galerie Konrad Fischer.

Konrad Fischer (1939–1996) studied art with Gerhard Richter and Sigmar Polke at the Academy of Art in Düsseldorf before he decided to open a gallery for contemporary art together with his wife Dorothee (1937–2015) in 1967. In a passageway, which he remodeled and enclosed, on Neubrückstraße in the old town of Düsseldorf, he hosted exhibitions of young international artists. Galerie Fischer presented Minimal and Conceptual Art, and it quickly became one of the pioneers of the European avant-garde in which site-specific works, institutional critique, and questions about authorship expanded the traditional notion of the artwork. The gallery also showed artists such as Lawrence Weiner and Sol LeWitt, who occasionally even left the execution of a work entirely in the hands of someone else. With the increasing disintegration of the boundaries between document and work, the differences between collection and archive also began to blur. This indistinguishability is what defines the structure of the Dorothee and Konrad Fischer Collection and Archive.

Thanks to the help of the Zentralarchiv für deutsche und internationale Kunstmarktforschung (Central Archive for the Research of the German and International Art Market, ZADIK) in Cologne, the Dorothee and Konrad Fischer Archive is now catalogued and digitized. Researchers can now access the digital archive, along with other major collections of modern art history, at the ZADIK. The originals, which are permanently stored in a room in K21 designed specifically for this purpose, can be viewed in continually changing thematic presentations that also relate to the museum’s collection.