Abstract: Disclosed is a clean air hood for disposition above the print head of a fluid jet printing apparatus having an orifice plate on one side of the print head for forming a plurality of droplet streams. The droplet streams flow past charge and deflection electrode means as well as a fluid catcher whereby uncharged droplets are deposited on a substrate. The clean air hood includes an interior baffle for directing clean air through the hood for issuance through a pair of laterally spaced slots along opposite sides of the hood whereby the air curtains formed thereby straddle the print head. In operation, the air curtains flow along opposite sides of the print head and opposite sides of the droplet streams ot maintain a clean air region about the electrode means and dampen any tendency of particulate matter carried by the substrate from migrating into the region of the electrodes. The print bar is rotated 180.degree.