The central idea Correggio developed across his Parma commissions, small and large, was to make a ceiling disappear. Rather than framing a scene within a painted architectural border, as earlier ceiling painters had done, Correggio removed the sense of a hard upper boundary altogether, replacing it with what appeared to be an opening onto real sky^[1]. Andrea Mantegna had experimented with a related effect decades earlier in the Camera degli Sposi in Mantua, painting an oculus through which foreshortened putti and spectators seem to look down into the room below, and Correggio is recorded as having studied that model closely before developing his own, more ambitious versions of the same illusion^[2][1].

The scale and setting of Correggio's ceiling projects grew considerably after his early work for private patrons. His fresco of Christ and the apostles in the cupola of San Giovanni Evangelista, painted around 1520 to 1522, dissolved an entire dome roughly thirty by twenty-seven feet across and a hundred feet above the floor, removing the usual lantern that would have lit the space and replacing it with a painted glory of light at the centre^[1]. The Assumption of the Virgin in the dome of Parma Cathedral, completed a few years later, pushed the same idea further still, filling the cathedral's dome with soaring, weightless figures that seem entirely free of gravity^[3][4]. Both projects rest on the same basic conceptual move as the small painted trellis of San Paolo: make the architecture seem to open directly onto the divine, whether that divinity takes the mythological form of putti in a garden or the religious form of Christ ascending into glory.

Correggio, properly Antonio Allegri, spent almost the whole of his working life in and around Parma, a relatively minor art centre by the standards of Florence, Rome or Venice, yet one where he had access, at some remove, to the innovations of Leonardo, Michelangelo and Raphael and to the Venetian colourists of his own generation^[5]. He absorbed these influences without directly copying any of them, developing instead his own soft, blended modelling of light, later admirers coming to see him as one of the most progressive painters of the entire Renaissance despite his comparative geographic isolation^[4]. His illusionistic ceiling technique had no immediate successors in his own lifetime and was largely overshadowed for decades by Mannerism, but from around 1600 it began to be recognised as a direct ancestor of Baroque ceiling decoration, and Correggio's reputation rose accordingly^[5].