Topic summary
Quadratura

Extracted from the Wikipedia article Illusionistic ceiling painting.
Quadratura
Quadratura, a term which was introduced in the seventeenth century and is also normally used in English, became popular with Baroque artists. Although it can also refer to the "opening up" of walls through architectural illusion, the term is most commonly associated with Italian ceiling painting. Unlike other trompe-l'œil techniques or precedent di sotto in sù ceiling decorations, which often rely on intuitive artistic approaches to deception, quadratura is directly tied to seventeenth-century theories of perspective and the representation of architectural space. Due to its reliance on perspective theory, it more fully unites architecture, painting and sculpture and gives a more overwhelming impression of illusionism than earlier examples.