We report an experimental investigation and comparison with simulation of the x-ray focusing of a flat, square profile microchannel plate. We use x rays with an energy of ~1.5 keV from a laser-produced plasma. The images were recorded with x-ray film. We find the focal structure to be consistent with theoretical expectations. The angular resolution of the focus is 0.96 mrad, which is a major improvement over previous results. The measured peak intensity gain is 27 ± 4, which is ~33% of that for a perfect optic.