Abstract: One or more wheel-air bustling devices are adjustably mounted between successive printing units of a multicolor printing press, to form adjustable bustles or ridges in the printed paper web. The bustles effectively shrink the width of the web, back to its original width, so that the previously printed color image is brought into precise registration with the next printed color image. Each bustling device comprises a body adjustably clamped to a supporting rod, a hollow tubular externally threaded stem movable through a guide opening in the body, an internally threaded adjusting knob received around the stem and rotatably retained on the body for longitudinally adjusting the stem, an air nozzle mounted on the upper end of the stem for directing an air jet against the web to form a longitudinal bustle or ridge therein, and a bustle wheel mounted on a bustle frame which is adjustable along the stem to raise and lower the wheel between operative and inoperative positions.