Restoration of the Sistine Chapel frescoes smoke and exhaust fumes of the city, being "much dirtier than the ceiling proper". The building was a little unstable and had already shifted considerably prior to Michelangelo's work of 1508, causing cracking of the ceiling, the crack in the "Judith" pendentive being so large that it had to be filled with bricks and mortar before painting. The upper part of the ceiling provided Michelangelo an irregular surface due to cracks and water seepage. Continued ingress of water from the roof and from unroofed exterior walkways above the ceiling level had caused seepage which carried down salts from the building
Illusionistic ceiling painting Sant'Ignazio, Rome. Illusionistic ceiling painting belongs to the general class of illusionism in art—art designed to create accurate representations of reality. Di sotto in sù (or "sotto in su"), which means "seen from below" or "from below, upward" in Italian, developed in late Quattrocento Italian Renaissance painting, notably in Andrea Mantegna's Camera degli Sposi in Mantua and in frescoes by Melozzo da Forlì. Italian terminology for this technique reflects the latter artist's influence and is called "prospettiva melozziana", or "Melozzo's perspective". Another notable use is by Antonio da Correggio in the Duomo of Parma, which foreshadows Baroque grandeur. The technique