Proun (project for the approval of the new) is a neologism invented by El Lissitzky to refer to the new artistic system he invented, which connected the idea of a geometric plane with the laws of constructive construction of a three-dimensional form. Proun's plastic idea was born at the end of 1919; the term, consonant with the name of the UNOVIS group, Lissitzky came up with in the fall of 1920.

The impetus for the birth of the prouns was Malevich's assignment given to Lissitzky in Vitebsk - the translation of Suprematism into three-dimensional forms: three-dimensional constructions were to lay the foundations for the architectural concept of the future. In late 1919 - early 1920 Lissitzky experimented with the spatial interpretation of Suprematism. The virtuoso transformation of a plane into volume and back, visual dissolution of a plane, the effect of transparency, the interpenetration of volumetric and flat figures solved the problem of creating a new plastic concept of the relationship between an object and space.

Proun motifs were often repeated and varied in different techniques - easel graphics, painting and lithography.