"In this latest issue of Cahiers d'Art featuring Philippe Parreno, the artist revisits 30 years of exhibition practice through an assemblage of rarely-seen images of his work. They are not a collection of artworks, but the by-products of Parreno's practice (weather stations and sensors of all types, shadows cast by works, computer programs, loudspeakers, or exhibition viewers...) They are devices used to collect data and inform the exhibition process, at the center or in the periphery of his work. The selected images come in pairs, each one functioning as the counterpoint to the one facing it. Side by side they reveal connections and expose a continuity within a complex system of creation. The patterns and motifs assembled in this volume reveal the spectral agents seen in the pictures that Parreno has been collecting throughout his career. As a collection of elements that appear and reappear in the artist's work, this number of Cahiers d'Art will explore the nature of his process, its raison d'être, and its motive. A conversation between Philippe Parreno and Hans Ulrich Obrist will expand on the artist's vision for this issue of la revue.