An engraving laser assembly comprises a tubular rail defining a plenum in an interior of the rail. A carriage is operatively associated with to the tubular rail for axial movement along the rail. A focusing optic is mounted to the carriage for focusing a laser beam to a focal point on an engraving plane operatively with the carriage. A gas inlet is operatively associated with the tubular rail and the inlet is configured for attachment to a source of pressurized gas to provide pressurized gas to the plenum. A plurality of holes are provided in the tubular rail in fluid communication with the plenum. The holes are configured so that, with a source of pressurized gas attached to the gas inlet, a stream of pressurized gas is directed from each hole toward the engraving plane.