Abstract: A novel adjustable width paperboard or corrugated paper tray having a tray telescopically associated with a tray support. Engagement devices, preferably in the form of a plurality of spaced serrations or triangular shaped projections associated with each inner wall of the tray support and with the inner wall of the tray, are integrally formed with the tray and the tray support and matingly engage with each other in a fashion that can be disengaged so that the tray can be moved to a desired width and the serrations re-engaged to lock the tray in the desired position.