The instrument focal plane mask program at the Large Binocular Telescope

Facility Instruments at the Large Binocular Telescope (LBT) include two spectrograph pairs, the LBT Near-IR Spectroscopic Utility with Camera and Integral Field Unit for Extragalactic Research (LUCI), a near-infrared imager and spectrograph pair, and the Multi-Object Double Spectrograph (MODS), a pair of dual-beam long-slit spectrographs. Both spectrograph designs utilize focal plane masks for long-slit and multi-slit observations. This paper describes the mask configuration and specification process for each instrument, as well as the steps in mask fabrication, handling, and installation.