An apparatus is provided for planar flow casting of metal ribbon. The apparatus comprises a movable chill surface, a reservoir for holding molten metal and a slotted nozzle whose lips are located close to the chill surface. In operation, molten metal is forced through the nozzle onto the chill surface to form a melt puddle. Rapid cooling of the molten metal results in the formation of a continuous ribbon. Ribbon contour is controlled through the use of nozzle designs that provide reproducible configuration of the melt puddle and reduce turbulent air flow over the molten metal surface.