Enrico Crispolti, Lucio Fontana Catalogue raisonné des peintures, sculptures et environnements spatiaux, Brussels, 1974, Vol. II, page 202, ill. page 203; Enrico Crispolti, Lucio Fontana Catalogo generale, Milan 1986, Vol. II, page 691 with ill.Enrico Crispolti, Fontana Catalogo ragionato di sculture, dipinti, ambientazioni, Milan, 2006, Vol. II, page 884, with ill. The phenomenology of slashes, which are almost always monochrome, is defined by the quantity and variety of the slashes themselves, which vary from the single, scanted, and slightly arched one, according to a gestural trajectory, to the vertical slash of nigh architectural absoluteness, from a cadence in pairs following the same rhythm to multiple slashes with different, opposing directions, or rhythmically iterated. The slashes represent one of the cycles to which Fontana entrusted a sort of personal diary of moods and thoughts through lines written constantly on the reverse of the pictures from 1964 onwards. Such writings, which helped identify the authenticity of the works, contain references to nature, describe encounters or facts in Fontana’s life, or record external facts with references to space enterprises or sporting events, or are puns. However, from 1966 onwards, biographical references and a gradual reduction to domestic life reveal a progressive concentration on himself. The present work belongs to this period, the solemnity of the single vertical slash, the power and absoluteness of the gesture manifest themselves on a canvas of a rich, bright yellow, inventing a new pictorial language. Art will remain eternal as a gesture, but it will die as matter....We believe in freeing art from matter, in freeing the sense of eternity from the preoccupation of immortality. And we do not care whether a gesture, once it has been completed, lives for a moment or a millennium, because we are genuinely convinced that once it has been done, it is eternal... Lucio Fontana (First Manifesto of Spacialism, May 1947)