Abstract: A method for casting the print head of an ink jet printer employs a lost mold open at two opposite sides, one side being covered by transparent film onto which mold needles are lowered by means of a micro manipulator. The tips of the mold needles are imaged onto photodetectors, which furnishes signals for controlling operation of a micro manipulator for accurately positioning the tips of the mold needles. After the mold needles are inserted in position, the mold is filled with liquid synthetic material which, on hardening, forms the print head with micro channel ink conduits correctly defined by the positions of the mold needles.