1991
After 27 years big paintings are produced once again (so-called Chromatische Konstellationen)
The City Museum of Art in Düsseldorf purchases the ZERO-Raum from the documenta III in Kassel from 1964 with works by Mack, Piene and Uecker.

1992
Resigns from the Academy of Arts, Berlin
Works on the paintings for Hohelied Salomos
Great Culture Award from the Rheinischen Sparkassenverbandes

1994
Participation in the Bodensee conference (Topic: Culture and the Economy, Opposites or Symbiotic) with Max Bill
Lectures on the occasion of the foundation of the Dortmunder Kunstverein

1997
Working holiday in the deserts of Oman
Production of various profane glass windows
Intensive work on around 200 ceramic sculptures which are created in this year

1998
Comprehensive suite of paper works to Goethe's West-Östlicher Diwan

1998-1999
Multiple lithographs are created

1999
On the occasion of the 250th anniversary of the birth of Johann W. von Goethe the elaborate artistic book Mack - Ein Buch der Bilder zum West-Östlichen Divan from Johann Wolfgang  v. Goethe is published
Lectures in the Goethe Museum, Düsseldorf