Abstract: A method and apparatus (10) is provided for opening sheets of a signature (7) preparatory to its transport to a thread sewing machine. A plurality of suction plates (30, 32, 34, 36) are spaced from a conveying surface (12), each suction plate having a working surface facing the conveying surface. A plurality of emergent plates (58, 60, 62, 64), corresponding to the suction plates, are provided alongside the conveying surface and are substantially coplanar thereto. The suction plates have respective pivotal mounts (86, 88, 90, 92) proximate their midpoints. At or about the time the signature is positioned in proximity to a suction plate, suction is induced through the suction plate, and an associated emergent plate is actuated to present the signature to the suction plate, bringing a signature sheet into engagement with the working surface of the suction plate.