A multibeam backlight and multiview display employ a filling fraction of a diffraction grating to control diffractive scattering efficiency. The multibeam backlight includes a light guide configured to guide light and a plurality of multibeam elements, a multibeam element of the multibeam element plurality including a diffraction grating. The multibeam element is configured to diffractively scatter a portion of the guided light out of the light guide as directional light beams having different directions corresponding to different view directions of a multiview display. A filling fraction of diffractive features within the diffraction grating is configured to control a diffractive scattering efficiency of the multibeam element. The multiview display further includes an array of light valves configured to modulate the directional light beams to provide a multiview image. The filling fraction may be a ratio of diffractive features to filling features within the diffraction grating.