FIELD: jet printing equipment. SUBSTANCE: semitone point-contact screen has plurality of semitone cells corresponding to required tones. Each of semitone cell has plurality of addressable points, with at least part of addressable points being "switched on" for designating semitone point-contact screen. Part of "switched-on" points designating middle portion of semitone point-contact screen is selectively "switched-off" to form thinned semitone point-contact screen. Thinned semitone cells may be kept in memory as classification signs (typesetting signs in digital form) and may be searched for and retrieved by jet printing system for printing semitone pictures with increased addressing extent. EFFECT: improved quality of picture by increased variety of shades. 7 cl, 12 dwg
