The disclosed device comprises a roller, rotatably mounted on a pivotable arm, for maintaining rolling contact with the edges of sheets being adhesively laminated. One of the sheets is rather stiff board and the other a thin gauge sheet covering one side of the board. As the laminated sheets advance the roller, which is in pressure engagement with the edges of the board parallel to the direction of movement, moves laterally inwardly to also provide rolling contact with the lateral trailing edge of the board. In doing so the corners of the thin wrap are pressed tightly against the edges of the board to produce well defined corners.