the collecting tray of a ink - jet printer is equipped with a guard to prevent the paper immediately after exiting from the printer to fall to the bottom of the tray . the guard is much narrower than the width of the tray so that the guard tilts the paper . a succeeding sheet of paper pushes the tilted paper until the tilted paper is pushed beyond the end of the guard and falls to the bottom of the tray after a time delay for the ink to dry .