We describe a design for bolometric detectors of infrared and mm-wave radiation produced in large-format filled arrays by standard planar lithography. A square grid of metallized silicon nitride absorbs the radiation. The bolometer suspension, sensor, and wiring occupy a small fraction of the area. We have produced a 1024 element array of fully released and suspended 1.5 mm x 1.5 mm bolometer micromeshes with a filling factor of 88%. We describe a voltage-biased superconducting bolometer built as a prototype for one array element. We have measured noise equivalent power = 2.3 x 10(-17) W/root Hz, tau = 24 ms, and G = 2.7 x 10(-11) W/K at 304 mK. (C) 2000 American Institute of Physics. [S0003-6951(00)00947-5].