Precision writing line control platen for high resolution ink jet printing

1. Field of the Invention An ink jet printer jets ink onto a section of a front side of a print medium. The ink jet printer includes an ink jetting printhead facing the front side of the print medium. A media support apparatus opposes the printhead. The media support apparatus includes a substantially flexible body having an outer surface engaging a back side of the print medium such that the section of the print medium receiving the ink is substantially flat. A substantially rigid elongate element engages the body and has a length direction substantially perpendicular to a feed direction of the print medium. The elongate element provides at least a portion of the outer surface of the body with a predetermined degree of straightness.