Sistine Chapel ceiling restoration began on 7 November 1984. The restoration complete, the chapel was re-opened to the public on 8 April 1994. The part of the restoration in the Sistine Chapel that has caused the most concern is the ceiling, painted by Michelangelo. The emergence of the brightly coloured Ancestors of Christ from the gloom sparked a reaction of fear that the processes being employed in the cleaning were too severe and removed the original intent of the artist. The problem lies in the analysis and understanding of the techniques utilised by Michelangelo, and the technical response of the restorers to
Illusionistic ceiling painting sotto in sù". This was the prototype of illusionistic ceiling painting that was to become an important element of Italian baroque. Correggio at Parma took the illusionistic ceiling a step farther in his frescoes of Christ and the Apostles for the cupola at the San Giovanni Evangelista and in the "Assumption of the Virgin" in the dome of the Cathedral of Parma, which is Correggio's most famous work (1520–24); in these frescos Correggio treats the entire surface as the vast and frameless vault of heaven in which the figures float. In a visual continuity between the architectural interior and its